Nowadays, we call it "GUP-fast", the external interface includes functions
like "get_user_pages_fast()", and we renamed all internal functions to
reflect that as well.
Let's make the config option reflect that.
Link: https://lkml.kernel.org/r/20240402125516.223131-3-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Cc: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The access_error() of vma is already checked under per-VMA lock, if it is
a bad access, directly handle error, no need to retry with mmap_lock
again. In order to release the correct lock, pass the mm_struct into
bad_area_access_error(). If mm is NULL, release vma lock, or release
mmap_lock. Since the page faut is handled under per-VMA lock, count it as
a vma lock event with VMA_LOCK_SUCCESS.
Link: https://lkml.kernel.org/r/20240403083805.1818160-8-wangkefeng.wang@huawei.com
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
When memory is being placed, mmap() will take care to respect the guard
gaps of certain types of memory (VM_SHADOWSTACK, VM_GROWSUP and
VM_GROWSDOWN). In order to ensure guard gaps between mappings, mmap()
needs to consider two things:
1. That the new mapping isn't placed in an any existing mappings guard
gaps.
2. That the new mapping isn't placed such that any existing mappings
are not in *its* guard gaps.
The longstanding behavior of mmap() is to ensure 1, but not take any care
around 2. So for example, if there is a PAGE_SIZE free area, and a mmap()
with a PAGE_SIZE size, and a type that has a guard gap is being placed,
mmap() may place the shadow stack in the PAGE_SIZE free area. Then the
mapping that is supposed to have a guard gap will not have a gap to the
adjacent VMA.
Now that the vm_flags is passed into the arch get_unmapped_area()'s, and
vm_unmapped_area() is ready to consider it, have VM_SHADOW_STACK's get
guard gap consideration for scenario 2.
Link: https://lkml.kernel.org/r/20240326021656.202649-14-rick.p.edgecombe@intel.com
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Aneesh Kumar K.V <aneesh.kumar@kernel.org>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Deepak Gupta <debug@rivosinc.com>
Cc: Guo Ren <guoren@kernel.org>
Cc: Helge Deller <deller@gmx.de>
Cc: H. Peter Anvin (Intel) <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Naveen N. Rao <naveen.n.rao@linux.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
When memory is being placed, mmap() will take care to respect the guard
gaps of certain types of memory (VM_SHADOWSTACK, VM_GROWSUP and
VM_GROWSDOWN). In order to ensure guard gaps between mappings, mmap()
needs to consider two things:
1. That the new mapping isn't placed in an any existing mappings guard
gaps.
2. That the new mapping isn't placed such that any existing mappings
are not in *its* guard gaps.
The longstanding behavior of mmap() is to ensure 1, but not take any care
around 2. So for example, if there is a PAGE_SIZE free area, and a mmap()
with a PAGE_SIZE size, and a type that has a guard gap is being placed,
mmap() may place the shadow stack in the PAGE_SIZE free area. Then the
mapping that is supposed to have a guard gap will not have a gap to the
adjacent VMA.
Add x86 arch implementations of arch_get_unmapped_area_vmflags/_topdown()
so future changes can allow the guard gap of type of vma being placed to
be taken into account. This will be used for shadow stack memory.
Link: https://lkml.kernel.org/r/20240326021656.202649-13-rick.p.edgecombe@intel.com
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Aneesh Kumar K.V <aneesh.kumar@kernel.org>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Deepak Gupta <debug@rivosinc.com>
Cc: Guo Ren <guoren@kernel.org>
Cc: Helge Deller <deller@gmx.de>
Cc: H. Peter Anvin (Intel) <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Naveen N. Rao <naveen.n.rao@linux.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Future changes will need to add a new member to struct
vm_unmapped_area_info. This would cause trouble for any call site that
doesn't initialize the struct. Currently every caller sets each member
manually, so if new ones are added they will be uninitialized and the core
code parsing the struct will see garbage in the new member.
It could be possible to initialize the new member manually to 0 at each
call site. This and a couple other options were discussed. Having some
struct vm_unmapped_area_info instances not zero initialized will put those
sites at risk of feeding garbage into vm_unmapped_area(), if the
convention is to zero initialize the struct and any new field addition
missed a call site that initializes each field manually. So it is useful
to do things similar across the kernel.
The consensus (see links) was that in general the best way to accomplish
taking into account both code cleanliness and minimizing the chance of
introducing bugs, was to do C99 static initialization. As in: struct
vm_unmapped_area_info info = {};
With this method of initialization, the whole struct will be zero
initialized, and any statements setting fields to zero will be unneeded.
The change should not leave cleanup at the call sides.
While iterating though the possible solutions a few archs kindly acked
other variations that still zero initialized the struct. These sites have
been modified in previous changes using the pattern acked by the
respective arch.
So to be reduce the chance of bugs via uninitialized fields, perform a
tree wide change using the consensus for the best general way to do this
change. Use C99 static initializing to zero the struct and remove and
statements that simply set members to zero.
Link: https://lkml.kernel.org/r/20240326021656.202649-11-rick.p.edgecombe@intel.com
Link: https://lore.kernel.org/lkml/202402280912.33AEE7A9CF@keescook/#t
Link: https://lore.kernel.org/lkml/j7bfvig3gew3qruouxrh7z7ehjjafrgkbcmg6tcghhfh3rhmzi@wzlcoecgy5rs/
Link: https://lore.kernel.org/lkml/ec3e377a-c0a0-4dd3-9cb9-96517e54d17e@csgroup.eu/
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Aneesh Kumar K.V <aneesh.kumar@kernel.org>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Deepak Gupta <debug@rivosinc.com>
Cc: Guo Ren <guoren@kernel.org>
Cc: Helge Deller <deller@gmx.de>
Cc: H. Peter Anvin (Intel) <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Naveen N. Rao <naveen.n.rao@linux.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The mm_struct contains a function pointer *get_unmapped_area(), which is
set to either arch_get_unmapped_area() or arch_get_unmapped_area_topdown()
during the initialization of the mm.
Since the function pointer only ever points to two functions that are
named the same across all arch's, a function pointer is not really
required. In addition future changes will want to add versions of the
functions that take additional arguments. So to save a pointers worth of
bytes in mm_struct, and prevent adding additional function pointers to
mm_struct in future changes, remove it and keep the information about
which get_unmapped_area() to use in a flag.
Add the new flag to MMF_INIT_MASK so it doesn't get clobbered on fork by
mmf_init_flags(). Most MM flags get clobbered on fork. In the
pre-existing behavior mm->get_unmapped_area() would get copied to the new
mm in dup_mm(), so not clobbering the flag preserves the existing behavior
around inheriting the topdown-ness.
Introduce a helper, mm_get_unmapped_area(), to easily convert code that
refers to the old function pointer to instead select and call either
arch_get_unmapped_area() or arch_get_unmapped_area_topdown() based on the
flag. Then drop the mm->get_unmapped_area() function pointer. Leave the
get_unmapped_area() pointer in struct file_operations alone. The main
purpose of this change is to reorganize in preparation for future changes,
but it also converts the calls of mm->get_unmapped_area() from indirect
branches into a direct ones.
The stress-ng bigheap benchmark calls realloc a lot, which calls through
get_unmapped_area() in the kernel. On x86, the change yielded a ~1%
improvement there on a retpoline config.
In testing a few x86 configs, removing the pointer unfortunately didn't
result in any actual size reductions in the compiled layout of mm_struct.
But depending on compiler or arch alignment requirements, the change could
shrink the size of mm_struct.
Link: https://lkml.kernel.org/r/20240326021656.202649-3-rick.p.edgecombe@intel.com
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Aneesh Kumar K.V <aneesh.kumar@kernel.org>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Deepak Gupta <debug@rivosinc.com>
Cc: Guo Ren <guoren@kernel.org>
Cc: Helge Deller <deller@gmx.de>
Cc: H. Peter Anvin (Intel) <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Naveen N. Rao <naveen.n.rao@linux.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The comment in the code explains the reasons. We took a different
approach comparing to pmd_pfn() by providing a fallback function.
Another option is to provide some lower level config options (compare to
HUGETLB_PAGE or THP) to identify which layer an arch can support for such
huge mappings. However that can be an overkill.
[peterx@redhat.com: fix loongson defconfig]
Link: https://lkml.kernel.org/r/20240403013249.1418299-4-peterx@redhat.com
Link: https://lkml.kernel.org/r/20240327152332.950956-6-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Tested-by: Ryan Roberts <ryan.roberts@arm.com>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andrew Jones <andrew.jones@linux.dev>
Cc: Aneesh Kumar K.V (IBM) <aneesh.kumar@kernel.org>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: James Houghton <jthoughton@google.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Rik van Riel <riel@surriel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
follow_phys is only used by two callers in arch/x86/mm/pat/memtype.c.
Move it there and hardcode the two arguments that get the same values
passed by both callers.
[david@redhat.com: conflict resolutions]
Link: https://lkml.kernel.org/r/20240403212131.929421-4-david@redhat.com
Link: https://lkml.kernel.org/r/20240324234542.2038726-4-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Fei Li <fei1.li@intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "mm/mm_init.c: refactor free_area_init_core()".
In function free_area_init_core(), the code calculating
zone->managed_pages and the subtracting dma_reserve from DMA zone looks
very confusing.
From git history, the code calculating zone->managed_pages was for
zone->present_pages originally. The early rough assignment is for
optimize zone's pcp and water mark setting. Later, managed_pages was
introduced into zone to represent the number of managed pages by buddy.
Now, zone->managed_pages is zeroed out and reset in mem_init() when
calling memblock_free_all(). zone's pcp and wmark setting relying on
actual zone->managed_pages are done later than mem_init() invocation. So
we don't need rush to early calculate and set zone->managed_pages, just
set it as zone->present_pages, will adjust it in mem_init().
And also add a new function calc_nr_kernel_pages() to count up free but
not reserved pages in memblock, then assign it to nr_all_pages and
nr_kernel_pages after memmap pages are allocated.
This patch (of 6):
Variable dma_reserve and its usage was introduced in commit 0e0b864e06
("[PATCH] Account for memmap and optionally the kernel image as holes").
Its original purpose was to accounting for the reserved pages in DMA zone
to make DMA zone's watermarks calculation more accurate on x86.
However, currently there's zone->managed_pages to account for all
available pages for buddy, zone->present_pages to account for all present
physical pages in zone. What is more important, on x86, calculating and
setting the zone->managed_pages is a temporary move, all zone's
managed_pages will be zeroed out and reset to the actual value according
to how many pages are added to buddy allocator in mem_init(). Before
mem_init(), no buddy alloction is requested. And zone's pcp and watermark
setting are all done after mem_init(). So, no need to worry about the DMA
zone's setting accuracy during free_area_init().
Hence, remove memblock_find_dma_reserve() to stop calculating and
setting dma_reserve.
Link: https://lkml.kernel.org/r/20240325145646.1044760-1-bhe@redhat.com
Link: https://lkml.kernel.org/r/20240325145646.1044760-2-bhe@redhat.com
Signed-off-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
After redefining alloc_pages, all uses of that name are being replaced.
Change the conflicting names to prevent preprocessor from replacing them
when it's not intended.
Link: https://lkml.kernel.org/r/20240321163705.3067592-18-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Tested-by: Kees Cook <keescook@chromium.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alex Gaynor <alex.gaynor@gmail.com>
Cc: Alice Ryhl <aliceryhl@google.com>
Cc: Andreas Hindborg <a.hindborg@samsung.com>
Cc: Benno Lossin <benno.lossin@proton.me>
Cc: "Björn Roy Baron" <bjorn3_gh@protonmail.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Gary Guo <gary@garyguo.net>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wedson Almeida Filho <wedsonaf@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This API is not used anymore, drop it for the whole tree.
Link: https://lkml.kernel.org/r/20240318200404.448346-13-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Bjorn Andersson <andersson@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Fabio Estevam <festevam@denx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Konrad Dybcio <konrad.dybcio@linaro.org>
Cc: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Cc: Lucas Stach <l.stach@pengutronix.de>
Cc: Mark Salter <msalter@redhat.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This patch partly reverts below commits:
3a194f3f8a ("mm/hugetlb: make pud_huge() and follow_huge_pud() aware of non-present pud entry")
cbef8478be ("mm/hugetlb: pmd_huge() returns true for non-present hugepage")
Right now, pXd_huge() definition across kernel is unclear. We have two
groups that think differently on swap entries:
- x86/sparc: Allow pXd_huge() to accept swap entries
- all the rest: Doesn't allow pXd_huge() to accept swap entries
This is so confusing. Since the sparc helpers seem to be added in 2016,
which is after x86's (2015), so sparc could have followed a trend. x86
proposed such swap handling in 2015 to resolve hugetlb swap entries hit in
GUP, but now GUP guards swap entries with !pXd_present() in all layers so
we should be safe.
We should define this API properly, one way or another, rather than keep
them defined differently across archs.
Gut feeling tells me that pXd_huge() shouldn't include swap entries, and it
turns out that I am not the only one thinking so, the question was raised
when the current pmd_huge() for x86 was proposed by Ville Syrjälä:
https://lore.kernel.org/all/Y2WQ7I4LXh8iUIRd@intel.com/
I might also be missing something obvious, but why is it even necessary
to treat PRESENT==0+PSE==0 as a huge entry?
It is also questioned when Jason Gunthorpe reviewed the other patchset on
swap entry handlings:
https://lore.kernel.org/all/20240221125753.GQ13330@nvidia.com/
Revert its meaning back to original. It shouldn't have any functional
change as we should be ready with guards on !pXd_present() explicitly
everywhere.
Note that I also dropped the "#if CONFIG_PGTABLE_LEVELS > 2", it was there
probably because it was breaking things when 3a194f3f8a was proposed,
according to the report here:
https://lore.kernel.org/all/Y2LYXItKQyaJTv8j@intel.com/
Now we shouldn't need that.
Instead of reverting to _PAGE_PSE raw check, leverage pXd_leaf().
Link: https://lkml.kernel.org/r/20240318200404.448346-5-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Bjorn Andersson <andersson@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: David S. Miller <davem@davemloft.net>
Cc: Fabio Estevam <festevam@denx.de>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Konrad Dybcio <konrad.dybcio@linaro.org>
Cc: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Cc: Lucas Stach <l.stach@pengutronix.de>
Cc: Mark Salter <msalter@redhat.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Currently, the enforce_vmpl0() function uses a set argument when modifying
the VMPL1 permissions used to test for VMPL0. If the guest is not running
at VMPL0, the guest self-terminates.
The function is just a wrapper for a fixed RMPADJUST function. Eliminate
the function and perform the RMPADJUST directly.
No functional change.
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/ed01ddf04bfb475596b24b634fd26cffaa85173a.1713974291.git.thomas.lendacky@amd.com
The snp_init() function in boot/compressed/sev.c is local to that file, is
not called from outside of the file and is independent of the snp_init()
function in kernel/sev.c. Change the name to better differentiate when
each function is used.
Move the renamed snp_init() and related functions up in the file to avoid
having to add a forward declaration and make the function static.
No functional change.
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/afda29585c2724b9698003f24cefa77eb35f4ffb.1713974291.git.thomas.lendacky@amd.com
Ending a struct name with "layout" is a little redundant, so shorten the
snp_secrets_page_layout name to just snp_secrets_page.
No functional change.
[ bp: Rename the local pointer to "secrets" too for more clarity. ]
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/bc8d58302c6ab66c3beeab50cce3ec2c6bd72d6c.1713974291.git.thomas.lendacky@amd.com
Explicitly disallow enabling mitigations at runtime for kernels that were
built with CONFIG_CPU_MITIGATIONS=n, as some architectures may omit code
entirely if mitigations are disabled at compile time.
E.g. on x86, a large pile of Kconfigs are buried behind CPU_MITIGATIONS,
and trying to provide sane behavior for retroactively enabling mitigations
is extremely difficult, bordering on impossible. E.g. page table isolation
and call depth tracking require build-time support, BHI mitigations will
still be off without additional kernel parameters, etc.
[ bp: Touchups. ]
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20240420000556.2645001-3-seanjc@google.com
Rename x86's to CPU_MITIGATIONS, define it in generic code, and force it
on for all architectures exception x86. A recent commit to turn
mitigations off by default if SPECULATION_MITIGATIONS=n kinda sorta
missed that "cpu_mitigations" is completely generic, whereas
SPECULATION_MITIGATIONS is x86-specific.
Rename x86's SPECULATIVE_MITIGATIONS instead of keeping both and have it
select CPU_MITIGATIONS, as having two configs for the same thing is
unnecessary and confusing. This will also allow x86 to use the knob to
manage mitigations that aren't strictly related to speculative
execution.
Use another Kconfig to communicate to common code that CPU_MITIGATIONS
is already defined instead of having x86's menu depend on the common
CPU_MITIGATIONS. This allows keeping a single point of contact for all
of x86's mitigations, and it's not clear that other architectures *want*
to allow disabling mitigations at compile-time.
Fixes: f337a6a21e ("x86/cpu: Actually turn off mitigations by default for SPECULATION_MITIGATIONS=n")
Closes: https://lkml.kernel.org/r/20240413115324.53303a68%40canb.auug.org.au
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reported-by: Michael Ellerman <mpe@ellerman.id.au>
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Acked-by: Borislav Petkov (AMD) <bp@alien8.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240420000556.2645001-2-seanjc@google.com
New CPU #defines encode vendor and family as well as model.
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://lore.kernel.org/r/20240424181507.41693-1-tony.luck@intel.com
New CPU #defines encode vendor and family as well as model.
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://lore.kernel.org/r/20240424181506.41673-1-tony.luck@intel.com
The TDX guest platform takes one bit from the physical address to
indicate if the page is shared (accessible by VMM). This bit is not part
of the physical_mask and is not preserved during mprotect(). As a
result, the 'shared' bit is lost during mprotect() on shared mappings.
_COMMON_PAGE_CHG_MASK specifies which PTE bits need to be preserved
during modification. AMD includes 'sme_me_mask' in the define to
preserve the 'encrypt' bit.
To cover both Intel and AMD cases, include 'cc_mask' in
_COMMON_PAGE_CHG_MASK instead of 'sme_me_mask'.
Reported-and-tested-by: Chris Oo <cho@microsoft.com>
Fixes: 41394e33f3 ("x86/tdx: Extend the confidential computing API to support TDX guests")
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/all/20240424082035.4092071-1-kirill.shutemov%40linux.intel.com
cpu_feature_enabled(X86_FEATURE_OSPKE) does not necessarily reflect
whether CR4.PKE is set on the CPU. In particular, they may differ on
non-BSP CPUs before setup_pku() is executed. In this scenario, RDPKRU
will #UD causing the system to hang.
Fix by checking CR4 for PKE enablement which is always correct for the
current CPU.
The scenario happens by inserting a WARN* before setup_pku() in
identiy_cpu() or some other diagnostic which would lead to calling
__show_regs().
[ bp: Massage commit message. ]
Signed-off-by: David Kaplan <david.kaplan@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20240421191728.32239-1-bp@kernel.org
In our production environment, after removing monitor groups, those
unused RMIDs get stuck in the limbo list forever because their
llc_occupancy is always larger than the threshold. But the unused RMIDs
can be successfully freed by turning up the threshold.
In order to know how much the threshold should be, perf can be used to
acquire the llc_occupancy of RMIDs in each rdt domain.
Instead of using perf tool to track llc_occupancy and filter the log
manually, it is more convenient for users to use tracepoint to do this
work. So add a new tracepoint that shows the llc_occupancy of busy RMIDs
when scanning the limbo list.
Suggested-by: Reinette Chatre <reinette.chatre@intel.com>
Suggested-by: James Morse <james.morse@arm.com>
Signed-off-by: Haifeng Xu <haifeng.xu@shopee.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: James Morse <james.morse@arm.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Link: https://lore.kernel.org/r/20240408092303.26413-3-haifeng.xu@shopee.com
Now only the pseudo-locking part uses tracepoints to do event tracking,
but other parts of resctrl may need new tracepoints. It is unnecessary
to create separate header files and define CREATE_TRACE_POINTS in
different c files which fragments the resctrl tracing.
Therefore, give the resctrl tracepoint header file a generic name to
support its use for tracepoints that are not specific to pseudo-locking.
No functional change.
Suggested-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Haifeng Xu <haifeng.xu@shopee.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Link: https://lore.kernel.org/r/20240408092303.26413-2-haifeng.xu@shopee.com
The per-resource MSR update functions cat_wrmsr(), mba_wrmsr_intel(),
and mba_wrmsr_amd() all take three arguments:
(struct rdt_domain *d, struct msr_param *m, struct rdt_resource *r)
struct msr_param contains pointers to both struct rdt_resource and struct
rdt_domain, thus only struct msr_param is necessary.
Pass struct msr_param as a single parameter. Clean up formatting and
fix some fir tree declaration ordering.
No functional change.
Suggested-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Babu Moger <babu.moger@amd.com>
Tested-by: Maciej Wieczor-Retman <maciej.wieczor-retman@intel.com>
Link: https://lore.kernel.org/r/20240308213846.77075-3-tony.luck@intel.com
reset_all_ctrls() and resctrl_arch_update_domains() use on_each_cpu_mask()
to call rdt_ctrl_update() on potentially one CPU from each domain.
But this means rdt_ctrl_update() needs to figure out which domain to
apply changes to. Doing so requires a search of all domains in a resource,
which can only be done safely if cpus_lock is held. Both callers do hold
this lock, but there isn't a way for a function called on another CPU
via IPI to verify this.
Commit
c0d848fcb0 ("x86/resctrl: Remove lockdep annotation that triggers
false positive")
removed the incorrect assertions.
Add the target domain to the msr_param structure and call
rdt_ctrl_update() for each domain separately using
smp_call_function_single(). This means that rdt_ctrl_update() doesn't
need to search for the domain and get_domain_from_cpu() can safely
assert that the cpus_lock is held since the remaining callers do not use
IPI.
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: James Morse <james.morse@arm.com>
Reviewed-by: Babu Moger <babu.moger@amd.com>
Tested-by: Maciej Wieczor-Retman <maciej.wieczor-retman@intel.com>
Link: https://lore.kernel.org/r/20240308213846.77075-2-tony.luck@intel.com
Optimize virt_spin_lock() to use simpler and faster:
atomic_try_cmpxchg(*ptr, &val, new)
instead of:
atomic_cmpxchg(*ptr, val, new) == val
The x86 CMPXCHG instruction returns success in the ZF flag, so
this change saves a compare after the CMPXCHG.
Also optimize retry loop a bit. atomic_try_cmpxchg() fails iff
&lock->val != 0, so there is no need to load and compare the
lock value again - cpu_relax() can be unconditinally called in
this case. This allows us to generate optimized:
1f: ba 01 00 00 00 mov $0x1,%edx
24: 8b 03 mov (%rbx),%eax
26: 85 c0 test %eax,%eax
28: 75 63 jne 8d <...>
2a: f0 0f b1 13 lock cmpxchg %edx,(%rbx)
2e: 75 5d jne 8d <...>
...
8d: f3 90 pause
8f: eb 93 jmp 24 <...>
instead of:
1f: ba 01 00 00 00 mov $0x1,%edx
24: 8b 03 mov (%rbx),%eax
26: 85 c0 test %eax,%eax
28: 75 13 jne 3d <...>
2a: f0 0f b1 13 lock cmpxchg %edx,(%rbx)
2e: 85 c0 test %eax,%eax
30: 75 f2 jne 24 <...>
...
3d: f3 90 pause
3f: eb e3 jmp 24 <...>
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Waiman Long <longman@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20240422120054.199092-1-ubizjak@gmail.com
Macros __arch{,_try}_cmpxchg64_emu() are almost identical to their
local variants __arch{,_try}_cmpxchg64_emu_local(), differing only
by lock prefixes.
Merge these two macros by introducing additional macro parameters
to pass lock location and lock prefix from their respective static
inline functions.
No functional change intended.
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lore.kernel.org/r/20240417175830.161561-1-ubizjak@gmail.com
Commit a72bbec70d ("crash: hotplug support for kexec_load()")
introduced a new kexec flag, `KEXEC_UPDATE_ELFCOREHDR`. Kexec tool uses
this flag to indicate to the kernel that it is safe to modify the
elfcorehdr of the kdump image loaded using the kexec_load system call.
However, it is possible that architectures may need to update kexec
segments other then elfcorehdr. For example, FDT (Flatten Device Tree)
on PowerPC. Introducing a new kexec flag for every new kexec segment
may not be a good solution. Hence, a generic kexec flag bit,
`KEXEC_CRASH_HOTPLUG_SUPPORT`, is introduced to share the CPU/Memory
hotplug support intent between the kexec tool and the kernel for the
kexec_load system call.
Now we have two kexec flags that enables crash hotplug support for
kexec_load system call. First is KEXEC_UPDATE_ELFCOREHDR (only used in
x86), and second is KEXEC_CRASH_HOTPLUG_SUPPORT (for all architectures).
To simplify the process of finding and reporting the crash hotplug
support the following changes are introduced.
1. Define arch specific function to process the kexec flags and
determine crash hotplug support
2. Rename the @update_elfcorehdr member of struct kimage to
@hotplug_support and populate it for both kexec_load and
kexec_file_load syscalls, because architecture can update more than
one kexec segment
3. Let generic function crash_check_hotplug_support report hotplug
support for loaded kdump image based on value of @hotplug_support
To bring the x86 crash hotplug support in line with the above points,
the following changes have been made:
- Introduce the arch_crash_hotplug_support function to process kexec
flags and determine crash hotplug support
- Remove the arch_crash_hotplug_[cpu|memory]_support functions
Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Acked-by: Baoquan He <bhe@redhat.com>
Acked-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240326055413.186534-3-sourabhjain@linux.ibm.com
In the event of memory hotplug or online/offline events, the crash
memory hotplug notifier `crash_memhp_notifier()` receives a
`memory_notify` object but doesn't forward that object to the
generic and architecture-specific crash hotplug handler.
The `memory_notify` object contains the starting PFN (Page Frame Number)
and the number of pages in the hot-removed memory. This information is
necessary for architectures like PowerPC to update/recreate the kdump
image, specifically `elfcorehdr`.
So update the function signature of `crash_handle_hotplug_event()` and
`arch_crash_handle_hotplug_event()` to accept the `memory_notify` object
as an argument from crash memory hotplug notifier.
Since no such object is available in the case of CPU hotplug event, the
crash CPU hotplug notifier `crash_cpuhp_online()` passes NULL to the
crash hotplug handler.
Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Acked-by: Baoquan He <bhe@redhat.com>
Acked-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240326055413.186534-2-sourabhjain@linux.ibm.com
We have W=1 warnings on 64-bit because the pid is only
used in branches on 32-bit; move it inside to get rid of
the warnings.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Reviewed-by: Tiwei Bie <tiwei.btw@antgroup.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Start switching iomap_copy routines over to use #define and arch provided
inline/macro functions instead of weak symbols.
Inline functions allow more compiler optimization and this is often a
driver hot path.
x86 has the only weak implementation for __iowrite32_copy(), so replace it
with a static inline containing the same single instruction inline
assembly. The compiler will generate the "mov edx,ecx" in a more optimal
way.
Remove iomap_copy_64.S
Link: https://lore.kernel.org/r/1-v3-1893cd8b9369+1925-mlx5_arm_wc_jgg@nvidia.com
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
These functions are not called explicitly. Let's just workaround
the -Wmissing-prototypes warnings by declaring them locally similar
to what was done in arch/x86/kernel/asm-offsets_32.c.
This will address below -Wmissing-prototypes warnings:
./arch/x86/um/shared/sysdep/kernel-offsets.h:9:6: warning: no previous prototype for ‘foo’ [-Wmissing-prototypes]
arch/um/os-Linux/main.c:187:7: warning: no previous prototype for ‘__wrap_malloc’ [-Wmissing-prototypes]
arch/um/os-Linux/main.c:208:7: warning: no previous prototype for ‘__wrap_calloc’ [-Wmissing-prototypes]
arch/um/os-Linux/main.c:222:6: warning: no previous prototype for ‘__wrap_free’ [-Wmissing-prototypes]
arch/x86/um/user-offsets.c:17:6: warning: no previous prototype for ‘foo’ [-Wmissing-prototypes]
Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
This will address below -Wmissing-prototypes warnings:
arch/um/kernel/initrd.c:18:12: warning: no previous prototype for ‘read_initrd’ [-Wmissing-prototypes]
arch/um/kernel/um_arch.c:408:19: warning: no previous prototype for ‘read_initrd’ [-Wmissing-prototypes]
arch/um/os-Linux/start_up.c:301:12: warning: no previous prototype for ‘parse_iomem’ [-Wmissing-prototypes]
arch/x86/um/ptrace_32.c:15:6: warning: no previous prototype for ‘arch_switch_to’ [-Wmissing-prototypes]
arch/x86/um/ptrace_32.c:101:5: warning: no previous prototype for ‘poke_user’ [-Wmissing-prototypes]
arch/x86/um/ptrace_32.c:153:5: warning: no previous prototype for ‘peek_user’ [-Wmissing-prototypes]
arch/x86/um/ptrace_64.c:111:5: warning: no previous prototype for ‘poke_user’ [-Wmissing-prototypes]
arch/x86/um/ptrace_64.c:171:5: warning: no previous prototype for ‘peek_user’ [-Wmissing-prototypes]
arch/x86/um/syscalls_64.c:48:6: warning: no previous prototype for ‘arch_switch_to’ [-Wmissing-prototypes]
arch/x86/um/tls_32.c:184:5: warning: no previous prototype for ‘arch_switch_tls’ [-Wmissing-prototypes]
Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
This will address below -Wmissing-prototypes warnings:
arch/um/kernel/mem.c:202:8: warning: no previous prototype for ‘pgd_alloc’ [-Wmissing-prototypes]
arch/um/kernel/mem.c:215:7: warning: no previous prototype for ‘uml_kmalloc’ [-Wmissing-prototypes]
arch/um/kernel/process.c:207:6: warning: no previous prototype for ‘arch_cpu_idle’ [-Wmissing-prototypes]
arch/um/kernel/process.c:328:15: warning: no previous prototype for ‘arch_align_stack’ [-Wmissing-prototypes]
arch/um/kernel/reboot.c:45:6: warning: no previous prototype for ‘machine_restart’ [-Wmissing-prototypes]
arch/um/kernel/reboot.c:51:6: warning: no previous prototype for ‘machine_power_off’ [-Wmissing-prototypes]
arch/um/kernel/reboot.c:57:6: warning: no previous prototype for ‘machine_halt’ [-Wmissing-prototypes]
arch/um/kernel/skas/mmu.c:17:5: warning: no previous prototype for ‘init_new_context’ [-Wmissing-prototypes]
arch/um/kernel/skas/mmu.c:60:6: warning: no previous prototype for ‘destroy_context’ [-Wmissing-prototypes]
arch/um/kernel/skas/process.c:36:12: warning: no previous prototype for ‘start_uml’ [-Wmissing-prototypes]
arch/um/kernel/time.c:807:15: warning: no previous prototype for ‘calibrate_delay_is_known’ [-Wmissing-prototypes]
arch/um/kernel/tlb.c:594:6: warning: no previous prototype for ‘force_flush_all’ [-Wmissing-prototypes]
arch/x86/um/bugs_32.c:22:6: warning: no previous prototype for ‘arch_check_bugs’ [-Wmissing-prototypes]
arch/x86/um/bugs_32.c:44:6: warning: no previous prototype for ‘arch_examine_signal’ [-Wmissing-prototypes]
arch/x86/um/bugs_64.c:9:6: warning: no previous prototype for ‘arch_check_bugs’ [-Wmissing-prototypes]
arch/x86/um/bugs_64.c:13:6: warning: no previous prototype for ‘arch_examine_signal’ [-Wmissing-prototypes]
arch/x86/um/elfcore.c:10:12: warning: no previous prototype for ‘elf_core_extra_phdrs’ [-Wmissing-prototypes]
arch/x86/um/elfcore.c:15:5: warning: no previous prototype for ‘elf_core_write_extra_phdrs’ [-Wmissing-prototypes]
arch/x86/um/elfcore.c:42:5: warning: no previous prototype for ‘elf_core_write_extra_data’ [-Wmissing-prototypes]
arch/x86/um/elfcore.c:63:8: warning: no previous prototype for ‘elf_core_extra_data_size’ [-Wmissing-prototypes]
arch/x86/um/fault.c:18:5: warning: no previous prototype for ‘arch_fixup’ [-Wmissing-prototypes]
arch/x86/um/os-Linux/mcontext.c:7:6: warning: no previous prototype for ‘get_regs_from_mc’ [-Wmissing-prototypes]
arch/x86/um/os-Linux/tls.c:22:6: warning: no previous prototype for ‘check_host_supports_tls’ [-Wmissing-prototypes]
Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
This will also fix the warnings like:
warning: no previous prototype for ‘fork_handler’ [-Wmissing-prototypes]
140 | void fork_handler(void)
| ^~~~~~~~~~~~
Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
The MWAITX and MONITORX instructions generate the same #VC error code as
the MWAIT and MONITOR instructions, respectively. Update the #VC handler
opcode checking to also support the MWAITX and MONITORX opcodes.
Fixes: e3ef461af3 ("x86/sev: Harden #VC instruction emulation somewhat")
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/453d5a7cfb4b9fe818b6fb67f93ae25468bc9e23.1713793161.git.thomas.lendacky@amd.com
New CPU #defines encode vendor and family as well as model.
Update the example usage comment in arch/x86/kernel/cpu/match.c
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20240416211941.9369-4-tony.luck@intel.com
To avoid adding a slew of new macros for each new Intel CPU family
switch over from providing CPU model number #defines to a new
scheme that encodes vendor, family, and model in a single number.
[ bp: s/casted/cast/g ]
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20240416211941.9369-3-tony.luck@intel.com
Refactor struct cpuinfo_x86 so that the vendor, family, and model
fields are overlaid in a union with a 32-bit field that combines
all three (together with a one byte reserved field in the upper
byte).
This will make it easy, cheap, and reliable to check all three
values at once.
See
https://lore.kernel.org/r/Zgr6kT8oULbnmEXx@agluck-desk3
for why the ordering is (low-to-high bits):
(vendor, family, model)
[ bp: Move comments over the line, add the backstory about the
particular order of the fields. ]
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20240416211941.9369-2-tony.luck@intel.com
There are two menu entries for X86_EXTENDED_PLATFORM, one for X86_32 and
the other for X86_64.
These entries are nearly identical, with the only difference being the
platform list in the help message.
While this structure was intended by commit
8425091ff8 ("x86: improve the help text of X86_EXTENDED_PLATFORM"),
there is no need to duplicate the entire config entry. Instead, provide
a little more clarification in the help message.
[ bp: Massage. ]
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20240204100719.42574-1-masahiroy@kernel.org
-----BEGIN PGP SIGNATURE-----
iQIzBAABCgAdFiEEzv7L6UO9uDPlPSfHEsHwGGHeVUoFAmYk064ACgkQEsHwGGHe
VUo+Gg/9GvZD7InmNHQx+TZORbCphljcx110JxB0wh6l1hTdqy57VbLjZtnztCVt
EkFGku/5DEDLQVDD1VHvR6w8w3rayqBAhbGApnJfVGEDJfqyYBGXG4Nhx6qsJD5F
YBtgk+HZjZ7G5kmGlokgNKXmh4NadUwADbkBaV+iSXBQs+Teld1THJFylO7ju+rZ
jUttExna3YhsiHdcRwBhlxFwHm0SXsd591n9slTxNoIRg19SVAvfkYmcoL2W70c0
qtHtaVS37sHInFuVzI53W82hNfGLLgPt+vkQEtiG00CwR4956I2LkorsfAG3JwAA
CPlbgO3ypwWSJjSdRrvYkjn7pw9JtlMQMpVh+ypaMgQ1zucb6FpDEzHnAA4lbgNW
u31ALXlqhUcnKC/3HZC+vPQosRNSyBP2rWtNNdMZ3YKrW4vU/5zII+4foZj9kv3u
irH27Suh6aKMc1y6THNDZmwcgJIFRtvr3K1fm7WwM0z5qz5uNq3sOW5RIQTTL3ti
+lW7pK1NqUHZhTsOs09+kt/M7vfxyrMqk5qma18kgdgkaRCwCSJLcPGICVCM5WmD
mnLsbs15PIKdN4cwfqeC0KzWr/xroPn1VHiWgU9zZeXcEVss0+UDcMbopQERsXH0
6AJV5A0/H/PVfDFKs5aTdwzQXB3LKG2AGdGoX7KpN8vtHf5TFt4=
=YLBT
-----END PGP SIGNATURE-----
Merge tag 'sched_urgent_for_v6.9_rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fix from Borislav Petkov:
- Add a missing memory barrier in the concurrency ID mm switching
* tag 'sched_urgent_for_v6.9_rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched: Add missing memory barrier in switch_mm_cid
- Print the correct error code when FRED reports a bad event type
- Add a FRED-specific INT80 handler without the special dances that need
to happen in the current one
- Enable the using-the-default-return-thunk-but-you-should-not warning
only on configs which actually enable those special return thunks
- Check the proper feature flags when selecting BHI retpoline mitigation
-----BEGIN PGP SIGNATURE-----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=53Ih
-----END PGP SIGNATURE-----
Merge tag 'x86_urgent_for_v6.9_rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Borislav Petkov:
- Fix CPU feature dependencies of GFNI, VAES, and VPCLMULQDQ
- Print the correct error code when FRED reports a bad event type
- Add a FRED-specific INT80 handler without the special dances that
need to happen in the current one
- Enable the using-the-default-return-thunk-but-you-should-not warning
only on configs which actually enable those special return thunks
- Check the proper feature flags when selecting BHI retpoline
mitigation
* tag 'x86_urgent_for_v6.9_rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/cpufeatures: Fix dependencies for GFNI, VAES, and VPCLMULQDQ
x86/fred: Fix incorrect error code printout in fred_bad_type()
x86/fred: Fix INT80 emulation for FRED
x86/retpolines: Enable the default thunk warning only on relevant configs
x86/bugs: Fix BHI retpoline check
without OBJECT_FILES_NON_STANDARD. This fixes a warning
"Unpatched return thunk in use. This should not happen!" when running
KVM selftests.
* Fix a mostly benign bug in the gfn_to_pfn_cache infrastructure where KVM
would allow userspace to refresh the cache with a bogus GPA. The bug has
existed for quite some time, but was exposed by a new sanity check added in
6.9 (to ensure a cache is either GPA-based or HVA-based).
* Drop an unused param from gfn_to_pfn_cache_invalidate_start() that got left
behind during a 6.9 cleanup.
* Fix a math goof in x86's hugepage logic for KVM_SET_MEMORY_ATTRIBUTES that
results in an array overflow (detected by KASAN).
* Fix a bug where KVM incorrectly clears root_role.direct when userspace sets
guest CPUID.
* Fix a dirty logging bug in the where KVM fails to write-protect SPTEs used
by a nested guest, if KVM is using Page-Modification Logging and the nested
hypervisor is NOT using EPT.
x86 PMU:
* Drop support for virtualizing adaptive PEBS, as KVM's implementation is
architecturally broken without an obvious/easy path forward, and because
exposing adaptive PEBS can leak host LBRs to the guest, i.e. can leak
host kernel addresses to the guest.
* Set the enable bits for general purpose counters in PERF_GLOBAL_CTRL at
RESET time, as done by both Intel and AMD processors.
* Disable LBR virtualization on CPUs that don't support LBR callstacks, as
KVM unconditionally uses PERF_SAMPLE_BRANCH_CALL_STACK when creating the
perf event, and would fail on such CPUs.
Tests:
* Fix a flaw in the max_guest_memory selftest that results in it exhausting
the supply of ucall structures when run with more than 256 vCPUs.
* Mark KVM_MEM_READONLY as supported for RISC-V in set_memory_region_test.
-----BEGIN PGP SIGNATURE-----
iQFIBAABCAAyFiEE8TM4V0tmI4mGbHaCv/vSX3jHroMFAmYjdqcUHHBib256aW5p
QHJlZGhhdC5jb20ACgkQv/vSX3jHroPNRAgAh1AdKBAWnq9bFN2Np1kSAcRAk3bs
REDq/0iD1T9TvIwEmE1lHaRuqvCSO15WW+DKvbs7TS8zA0DyY7X/x8sIIy5YzZ5C
bQ+JXiqk55OAj0sPskBpCvE5qEreuU8qAit57+8OseKWs57EICvJjrfsRnHlmIub
pgGas3I42LjIgsuZRr2kjv+GrvaiikW+wWK6sq3CvPzTtHV196d26AK5l4NOoLkY
0FTbBIYUSJ7wxs92xuTed5mZ7JFZdsa5DVMXF5MRZ9W6g2vZCLbqCNRddRhSAsl0
gKmqZkuPTB7AnGQbJ2h/aKFT0ydsguzqbbKq62sK7ft5f1CUlbp9luDC9w==
=99rq
-----END PGP SIGNATURE-----
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm fixes from Paolo Bonzini:
"This is a bit on the large side, mostly due to two changes:
- Changes to disable some broken PMU virtualization (see below for
details under "x86 PMU")
- Clean up SVM's enter/exit assembly code so that it can be compiled
without OBJECT_FILES_NON_STANDARD. This fixes a warning "Unpatched
return thunk in use. This should not happen!" when running KVM
selftests.
Everything else is small bugfixes and selftest changes:
- Fix a mostly benign bug in the gfn_to_pfn_cache infrastructure
where KVM would allow userspace to refresh the cache with a bogus
GPA. The bug has existed for quite some time, but was exposed by a
new sanity check added in 6.9 (to ensure a cache is either
GPA-based or HVA-based).
- Drop an unused param from gfn_to_pfn_cache_invalidate_start() that
got left behind during a 6.9 cleanup.
- Fix a math goof in x86's hugepage logic for
KVM_SET_MEMORY_ATTRIBUTES that results in an array overflow
(detected by KASAN).
- Fix a bug where KVM incorrectly clears root_role.direct when
userspace sets guest CPUID.
- Fix a dirty logging bug in the where KVM fails to write-protect
SPTEs used by a nested guest, if KVM is using Page-Modification
Logging and the nested hypervisor is NOT using EPT.
x86 PMU:
- Drop support for virtualizing adaptive PEBS, as KVM's
implementation is architecturally broken without an obvious/easy
path forward, and because exposing adaptive PEBS can leak host LBRs
to the guest, i.e. can leak host kernel addresses to the guest.
- Set the enable bits for general purpose counters in
PERF_GLOBAL_CTRL at RESET time, as done by both Intel and AMD
processors.
- Disable LBR virtualization on CPUs that don't support LBR
callstacks, as KVM unconditionally uses
PERF_SAMPLE_BRANCH_CALL_STACK when creating the perf event, and
would fail on such CPUs.
Tests:
- Fix a flaw in the max_guest_memory selftest that results in it
exhausting the supply of ucall structures when run with more than
256 vCPUs.
- Mark KVM_MEM_READONLY as supported for RISC-V in
set_memory_region_test"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (30 commits)
KVM: Drop unused @may_block param from gfn_to_pfn_cache_invalidate_start()
KVM: selftests: Add coverage of EPT-disabled to vmx_dirty_log_test
KVM: x86/mmu: Fix and clarify comments about clearing D-bit vs. write-protecting
KVM: x86/mmu: Remove function comments above clear_dirty_{gfn_range,pt_masked}()
KVM: x86/mmu: Write-protect L2 SPTEs in TDP MMU when clearing dirty status
KVM: x86/mmu: Precisely invalidate MMU root_role during CPUID update
KVM: VMX: Disable LBR virtualization if the CPU doesn't support LBR callstacks
perf/x86/intel: Expose existence of callback support to KVM
KVM: VMX: Snapshot LBR capabilities during module initialization
KVM: x86/pmu: Do not mask LVTPC when handling a PMI on AMD platforms
KVM: x86: Snapshot if a vCPU's vendor model is AMD vs. Intel compatible
KVM: x86: Stop compiling vmenter.S with OBJECT_FILES_NON_STANDARD
KVM: SVM: Create a stack frame in __svm_sev_es_vcpu_run()
KVM: SVM: Save/restore args across SEV-ES VMRUN via host save area
KVM: SVM: Save/restore non-volatile GPRs in SEV-ES VMRUN via host save area
KVM: SVM: Clobber RAX instead of RBX when discarding spec_ctrl_intercepted
KVM: SVM: Drop 32-bit "support" from __svm_sev_es_vcpu_run()
KVM: SVM: Wrap __svm_sev_es_vcpu_run() with #ifdef CONFIG_KVM_AMD_SEV
KVM: SVM: Create a stack frame in __svm_vcpu_run() for unwinding
KVM: SVM: Remove a useless zeroing of allocated memory
...
On x86, the ordinary, position dependent small and kernel code models
only support placement of the executable in 32-bit addressable memory,
due to the use of 32-bit signed immediates to generate references to
global variables. For the kernel, this implies that all global variables
must reside in the top 2 GiB of the kernel virtual address space, where
the implicit address bits 63:32 are equal to sign bit 31.
This means the kernel code model is not suitable for other bare metal
executables such as the kexec purgatory, which can be placed arbitrarily
in the physical address space, where its address may no longer be
representable as a sign extended 32-bit quantity. For this reason,
commit
e16c2983fb ("x86/purgatory: Change compiler flags from -mcmodel=kernel to -mcmodel=large to fix kexec relocation errors")
switched to the large code model, which uses 64-bit immediates for all
symbol references, including function calls, in order to avoid relying
on any assumptions regarding proximity of symbols in the final
executable.
The large code model is rarely used, clunky and the least likely to
operate in a similar fashion when comparing GCC and Clang, so it is best
avoided. This is especially true now that Clang 18 has started to emit
executable code in two separate sections (.text and .ltext), which
triggers an issue in the kexec loading code at runtime.
The SUSE bugzilla fixes tag points to gcc 13 having issues with the
large model too and that perhaps the large model should simply not be
used at all.
Instead, use the position independent small code model, which makes no
assumptions about placement but only about proximity, where all
referenced symbols must be within -/+ 2 GiB, i.e., in range for a
RIP-relative reference. Use hidden visibility to suppress the use of a
GOT, which carries absolute addresses that are not covered by static ELF
relocations, and is therefore incompatible with the kexec loader's
relocation logic.
[ bp: Massage commit message. ]
Fixes: e16c2983fb ("x86/purgatory: Change compiler flags from -mcmodel=kernel to -mcmodel=large to fix kexec relocation errors")
Fixes: https://bugzilla.suse.com/show_bug.cgi?id=1211853
Closes: https://github.com/ClangBuiltLinux/linux/issues/2016
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Fangrui Song <maskray@google.com>
Acked-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/all/20240417-x86-fix-kexec-with-llvm-18-v1-0-5383121e8fb7@kernel.org/
To support TDX, KVM is enhanced to operate with #VE. For TDX, KVM uses the
suppress #VE bit in EPT entries selectively, in order to be able to trap
non-present conditions. However, #VE isn't used for VMX and it's a bug
if it happens. To be defensive and test that VMX case isn't broken
introduce an option ept_violation_ve_test and when it's set, BUG the vm.
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
Message-Id: <d6db6ba836605c0412e166359ba5c46a63c22f86.1705965635.git.isaku.yamahata@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Dump the contents of the #VE info data structure and assert that #VE does
not happen, but do not yet do anything with it.
No functional change intended, separated for clarity only.
Extracted from a patch by Isaku Yamahata <isaku.yamahata@intel.com>.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
TDX will use a different shadow PTE entry value for MMIO from VMX. Add a
member to kvm_arch and track value for MMIO per-VM instead of a global
variable. By using the per-VM EPT entry value for MMIO, the existing VMX
logic is kept working. Introduce a separate setter function so that guest
TD can use a different value later.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
Message-Id: <229a18434e5d83f45b1fcd7bf1544d79db1becb6.1705965635.git.isaku.yamahata@intel.com>
Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
To make use of the same value of shadow_mmio_mask and shadow_present_mask
for TDX and VMX, add Suppress-VE bit to shadow_mmio_mask and
shadow_present_mask so that they can be common for both VMX and TDX.
TDX will require shadow_mmio_mask and shadow_present_mask to include
VMX_SUPPRESS_VE for shared GPA so that EPT violation is triggered for
shared GPA. For VMX, VMX_SUPPRESS_VE doesn't matter for MMIO because the
spte value is defined so as to cause EPT misconfig.
Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
Message-Id: <97cc616b3563cd8277be91aaeb3e14bce23c3649.1705965635.git.isaku.yamahata@intel.com>
Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
For TD guest, the current way to emulate MMIO doesn't work any more, as KVM
is not able to access the private memory of TD guest and do the emulation.
Instead, TD guest expects to receive #VE when it accesses the MMIO and then
it can explicitly make hypercall to KVM to get the expected information.
To achieve this, the TDX module always enables "EPT-violation #VE" in the
VMCS control. And accordingly, for the MMIO spte for the shared GPA,
1. KVM needs to set "suppress #VE" bit for the non-present SPTE so that EPT
violation happens on TD accessing MMIO range. 2. On EPT violation, KVM
sets the MMIO spte to clear "suppress #VE" bit so the TD guest can receive
the #VE instead of EPT misconfiguration unlike VMX case. For the shared GPA
that is not populated yet, EPT violation need to be triggered when TD guest
accesses such shared GPA. The non-present SPTE value for shared GPA should
set "suppress #VE" bit.
Add "suppress #VE" bit (bit 63) to SHADOW_NONPRESENT_VALUE and
REMOVED_SPTE. Unconditionally set the "suppress #VE" bit (which is bit 63)
for both AMD and Intel as: 1) AMD hardware doesn't use this bit when
present bit is off; 2) for normal VMX guest, KVM never enables the
"EPT-violation #VE" in VMCS control and "suppress #VE" bit is ignored by
hardware.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com>
Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Message-Id: <a99cb866897c7083430dce7f24c63b17d7121134.1705965635.git.isaku.yamahata@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The TDX support will need the "suppress #VE" bit (bit 63) set as the
initial value for SPTE. To reduce code change size, introduce a new macro
SHADOW_NONPRESENT_VALUE for the initial value for the shadow page table
entry (SPTE) and replace hard-coded value 0 for it. Initialize shadow page
tables with their value.
The plan is to unconditionally set the "suppress #VE" bit for both AMD and
Intel as: 1) AMD hardware uses the bit 63 as NX for present SPTE and
ignored for non-present SPTE; 2) for conventional VMX guests, KVM never
enables the "EPT-violation #VE" in VMCS control and "suppress #VE" bit is
ignored by hardware.
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
Message-Id: <acdf09bf60cad12c495005bf3495c54f6b3069c9.1705965635.git.isaku.yamahata@intel.com>
[Remove unnecessary CONFIG_X86_64 check. - Paolo]
Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
x86_64 has the "interesting" property that the instruction size is
generally a bit shorter for instructions that operate on the 32-bit (or
less) part of registers, or registers that are in the original set of 8.
This patch adjusts the AES-XTS code to take advantage of that property
by changing the LEN parameter from size_t to unsigned int (which is all
that's needed and is what the non-AVX implementation uses) and using the
%eax register for KEYLEN.
This decreases the size of aes-xts-avx-x86_64.o by 1.2%.
Note that changing the kmovq to kmovd was going to be needed anyway to
make the AVX10/256 code really work on CPUs that don't support 512-bit
vectors (since the AVX10 spec says that 64-bit opmask instructions will
only be supported on processors that support 512-bit vectors).
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
- For conditionally subtracting 16 from LEN when decrypting a message
whose length isn't a multiple of 16, use the cmovnz instruction.
- Fold the addition of 4*VL to LEN into the sub of VL or 16 from LEN.
- Remove an unnecessary test instruction.
This results in slightly shorter code, both source and binary.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Decrease the amount of code specific to the different AES variants by
"right-aligning" the sequence of round keys, and for AES-128 and AES-192
just skipping irrelevant rounds at the beginning.
This shrinks the size of aes-xts-avx-x86_64.o by 13.3%, and it improves
the efficiency of AES-128 and AES-192. The tradeoff is that for AES-256
some additional not-taken conditional jumps are now executed. But these
are predicted well and are cheap on x86.
Note that the ARMv8 CE based AES-XTS implementation uses a similar
strategy to handle the different AES variants.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Since aesni_xts_enc() and aesni_xts_dec() are very similar, generate
them from a macro that's passed an argument enc=1 or enc=0. This
reduces the length of aesni-intel_asm.S by 112 lines while still
producing the exact same object file in both 32-bit and 64-bit mode.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
When encrypting a message whose length isn't a multiple of 16 bytes,
encrypt the last full block in the main loop. This works because only
decryption uses the last two tweaks in reverse order, not encryption.
This improves the performance of decrypting messages whose length isn't
a multiple of the AES block length, shrinks the size of
aes-xts-avx-x86_64.o by 5.0%, and eliminates two instructions (a test
and a not-taken conditional jump) when encrypting a message whose length
*is* a multiple of the AES block length.
While it's not super useful to optimize for ciphertext stealing given
that it's rarely needed in practice, the other two benefits mentioned
above make this optimization worthwhile.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Instead of loading the message words into both MSG and \m0 and then
adding the round constants to MSG, load the message words into \m0 and
the round constants into MSG and then add \m0 to MSG. This shortens the
source code slightly. It changes the instructions slightly, but it
doesn't affect binary code size and doesn't seem to affect performance.
Suggested-by: Stefan Kanthak <stefan.kanthak@nexgo.de>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
- Load the SHA-256 round constants relative to a pointer that points
into the middle of the constants rather than to the beginning. Since
x86 instructions use signed offsets, this decreases the instruction
length required to access some of the later round constants.
- Use punpcklqdq or punpckhqdq instead of longer instructions such as
pshufd, pblendw, and palignr. This doesn't harm performance.
The end result is that sha256_ni_transform shrinks from 839 bytes to 791
bytes, with no loss in performance.
Suggested-by: Stefan Kanthak <stefan.kanthak@nexgo.de>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
MSGTMP[0-3] are used to hold the message schedule and are not temporary
registers per se. MSGTMP4 is used as a temporary register for several
different purposes and isn't really related to MSGTMP[0-3]. Rename them
to MSG[0-3] and TMP accordingly.
Also add a comment that clarifies what MSG is.
Suggested-by: Stefan Kanthak <stefan.kanthak@nexgo.de>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
To avoid source code duplication, do the SHA-256 rounds using macros.
This reduces the length of sha256_ni_asm.S by 153 lines while still
producing the exact same object file.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Access the AES round keys using offsets -7*16 through 7*16, instead of
0*16 through 14*16. This allows VEX-encoded instructions to address all
round keys using 1-byte offsets, whereas before some needed 4-byte
offsets. This decreases the code size of aes-xts-avx-x86_64.o by 4.2%.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The codegen for is_mov_percpu_addr instruction works for rax/r8 registers
only. Fix it to generate proper x86 byte code for other registers.
Fixes: 7bdbf74463 ("bpf: add special internal-only MOV instruction to resolve per-CPU addrs")
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240417214406.15788-1-alexei.starovoitov@gmail.com
Fix cpuid_deps[] to list the correct dependencies for GFNI, VAES, and
VPCLMULQDQ. These features don't depend on AVX512, and there exist CPUs
that support these features but not AVX512. GFNI actually doesn't even
depend on AVX.
This prevents GFNI from being unnecessarily disabled if AVX is disabled
to mitigate the GDS vulnerability.
This also prevents all three features from being unnecessarily disabled
if AVX512VL (or its dependency AVX512F) were to be disabled, but it
looks like there isn't any case where this happens anyway.
Fixes: c128dbfa0f ("x86/cpufeatures: Enable new SSE/AVX/AVX512 CPU features")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lore.kernel.org/r/20240417060434.47101-1-ebiggers@kernel.org
Add a FRED-specific INT80 handler and document why it differs from the
current one. Eventually, the common bits will be unified once FRED hw is
available and it turns out that no further changes are needed but for
now, keep the handlers separate for everyone's sanity's sake.
[ bp: Zap duplicated commit message, massage. ]
Fixes: 55617fb991 ("x86/entry: Do not allow external 0x80 interrupts")
Suggested-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Signed-off-by: Xin Li (Intel) <xin@zytor.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20240417174731.4189592-1-xin@zytor.com
The using-default-thunk warning check makes sense only with
configurations which actually enable the special return thunks.
Otherwise, it fires on unrelated 32-bit configs on which the special
return thunks won't even work (they're 64-bit only) and, what is more,
those configs even go off into the weeds when booting in the
alternatives patching code, leading to a dead machine.
Fixes: 4461438a84 ("x86/retpoline: Ensure default return thunk isn't used at runtime")
Reported-by: Klara Modin <klarasmodin@gmail.com>
Reported-by: Erhard Furtner <erhard_f@mailbox.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Klara Modin <klarasmodin@gmail.com>
Link: https://lore.kernel.org/r/78e0d19c-b77a-4169-a80f-2eef91f4a1d6@gmail.com
Link: https://lore.kernel.org/r/20240413024956.488d474e@yea
Clean up SVM's enter/exit assembly code so that it can be compiled
without OBJECT_FILES_NON_STANDARD. The "standard" __svm_vcpu_run() can't
be made 100% bulletproof, as RBP isn't restored on #VMEXIT, but that's
also the case for __vmx_vcpu_run(), and getting "close enough" is better
than not even trying.
As for SEV-ES, after yet another refresher on swap types, I realized
KVM can simply let the hardware restore registers after #VMEXIT, all
that's missing is storing the current values to the host save area
(they are swap type B). This should provide 100% accuracy when using
stack frames for unwinding, and requires less assembly.
In between, build the SEV-ES code iff CONFIG_KVM_AMD_SEV=y, and yank out
"support" for 32-bit kernels in __svm_sev_es_vcpu_run, which was
unnecessarily polluting the code for a configuration that is disabled
at build time.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
- Fix a mostly benign bug in the gfn_to_pfn_cache infrastructure where KVM
would allow userspace to refresh the cache with a bogus GPA. The bug has
existed for quite some time, but was exposed by a new sanity check added in
6.9 (to ensure a cache is either GPA-based or HVA-based).
- Drop an unused param from gfn_to_pfn_cache_invalidate_start() that got left
behind during a 6.9 cleanup.
- Disable support for virtualizing adaptive PEBS, as KVM's implementation is
architecturally broken and can leak host LBRs to the guest.
- Fix a bug where KVM neglects to set the enable bits for general purpose
counters in PERF_GLOBAL_CTRL when initializing the virtual PMU. Both Intel
and AMD architectures require the bits to be set at RESET in order for v2
PMUs to be backwards compatible with software that was written for v1 PMUs,
i.e. for software that will never manually set the global enables.
- Disable LBR virtualization on CPUs that don't support LBR callstacks, as
KVM unconditionally uses PERF_SAMPLE_BRANCH_CALL_STACK when creating the
virtual LBR perf event, i.e. KVM will always fail to create LBR events on
such CPUs.
- Fix a math goof in x86's hugepage logic for KVM_SET_MEMORY_ATTRIBUTES that
results in an array overflow (detected by KASAN).
- Fix a flaw in the max_guest_memory selftest that results in it exhausting
the supply of ucall structures when run with more than 256 vCPUs.
- Mark KVM_MEM_READONLY as supported for RISC-V in set_memory_region_test.
- Fix a bug where KVM incorrectly thinks a TDP MMU root is an indirect shadow
root due KVM unnecessarily clobbering root_role.direct when userspace sets
guest CPUID.
- Fix a dirty logging bug in the where KVM fails to write-protect TDP MMU
SPTEs used for L2 if Page-Modification Logging is enabled for L1 and the L1
hypervisor is NOT using EPT (if nEPT is enabled, KVM doesn't use the TDP MMU
to run L2). For simplicity, KVM always disables PML when running L2, but
the TDP MMU wasn't accounting for root-specific conditions that force write-
protect based dirty logging.
-----BEGIN PGP SIGNATURE-----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=0hRN
-----END PGP SIGNATURE-----
Merge tag 'kvm-x86-fixes-6.9-rcN' of https://github.com/kvm-x86/linux into HEAD
- Fix a mostly benign bug in the gfn_to_pfn_cache infrastructure where KVM
would allow userspace to refresh the cache with a bogus GPA. The bug has
existed for quite some time, but was exposed by a new sanity check added in
6.9 (to ensure a cache is either GPA-based or HVA-based).
- Drop an unused param from gfn_to_pfn_cache_invalidate_start() that got left
behind during a 6.9 cleanup.
- Disable support for virtualizing adaptive PEBS, as KVM's implementation is
architecturally broken and can leak host LBRs to the guest.
- Fix a bug where KVM neglects to set the enable bits for general purpose
counters in PERF_GLOBAL_CTRL when initializing the virtual PMU. Both Intel
and AMD architectures require the bits to be set at RESET in order for v2
PMUs to be backwards compatible with software that was written for v1 PMUs,
i.e. for software that will never manually set the global enables.
- Disable LBR virtualization on CPUs that don't support LBR callstacks, as
KVM unconditionally uses PERF_SAMPLE_BRANCH_CALL_STACK when creating the
virtual LBR perf event, i.e. KVM will always fail to create LBR events on
such CPUs.
- Fix a math goof in x86's hugepage logic for KVM_SET_MEMORY_ATTRIBUTES that
results in an array overflow (detected by KASAN).
- Fix a flaw in the max_guest_memory selftest that results in it exhausting
the supply of ucall structures when run with more than 256 vCPUs.
- Mark KVM_MEM_READONLY as supported for RISC-V in set_memory_region_test.
- Fix a bug where KVM incorrectly thinks a TDP MMU root is an indirect shadow
root due KVM unnecessarily clobbering root_role.direct when userspace sets
guest CPUID.
- Fix a dirty logging bug in the where KVM fails to write-protect TDP MMU
SPTEs used for L2 if Page-Modification Logging is enabled for L1 and the L1
hypervisor is NOT using EPT (if nEPT is enabled, KVM doesn't use the TDP MMU
to run L2). For simplicity, KVM always disables PML when running L2, but
the TDP MMU wasn't accounting for root-specific conditions that force write-
protect based dirty logging.
Many architectures' switch_mm() (e.g. arm64) do not have an smp_mb()
which the core scheduler code has depended upon since commit:
commit 223baf9d17 ("sched: Fix performance regression introduced by mm_cid")
If switch_mm() doesn't call smp_mb(), sched_mm_cid_remote_clear() can
unset the actively used cid when it fails to observe active task after it
sets lazy_put.
There *is* a memory barrier between storing to rq->curr and _return to
userspace_ (as required by membarrier), but the rseq mm_cid has stricter
requirements: the barrier needs to be issued between store to rq->curr
and switch_mm_cid(), which happens earlier than:
- spin_unlock(),
- switch_to().
So it's fine when the architecture switch_mm() happens to have that
barrier already, but less so when the architecture only provides the
full barrier in switch_to() or spin_unlock().
It is a bug in the rseq switch_mm_cid() implementation. All architectures
that don't have memory barriers in switch_mm(), but rather have the full
barrier either in finish_lock_switch() or switch_to() have them too late
for the needs of switch_mm_cid().
Introduce a new smp_mb__after_switch_mm(), defined as smp_mb() in the
generic barrier.h header, and use it in switch_mm_cid() for scheduler
transitions where switch_mm() is expected to provide a memory barrier.
Architectures can override smp_mb__after_switch_mm() if their
switch_mm() implementation provides an implicit memory barrier.
Override it with a no-op on x86 which implicitly provide this memory
barrier by writing to CR3.
Fixes: 223baf9d17 ("sched: Fix performance regression introduced by mm_cid")
Reported-by: levi.yun <yeoreum.yun@arm.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> # for arm64
Acked-by: Dave Hansen <dave.hansen@linux.intel.com> # for x86
Cc: <stable@vger.kernel.org> # 6.4.x
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20240415152114.59122-2-mathieu.desnoyers@efficios.com
Introduce arch_try_cmpxchg64_local() for 64-bit and 32-bit targets
to improve code using cmpxchg64_local(). On 64-bit targets, the
generated assembly improves from:
3e28: 31 c0 xor %eax,%eax
3e2a: 4d 0f b1 7d 00 cmpxchg %r15,0x0(%r13)
3e2f: 48 85 c0 test %rax,%rax
3e32: 0f 85 9f 00 00 00 jne 3ed7 <...>
to:
3e28: 31 c0 xor %eax,%eax
3e2a: 4d 0f b1 7d 00 cmpxchg %r15,0x0(%r13)
3e2f: 0f 85 9f 00 00 00 jne 3ed4 <...>
where a TEST instruction after CMPXCHG is saved. The improvements
for 32-bit targets are even more noticeable, because double-word
compare after CMPXCHG8B gets eliminated.
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Waiman Long <longman@redhat.com>
Link: https://lore.kernel.org/r/20240414161257.49145-1-ubizjak@gmail.com
When running as Xen PV guest in some cases W^X violation WARN()s have
been observed. Those WARN()s are produced by verify_rwx(), which looks
into the PTE to verify that writable kernel pages have the NX bit set
in order to avoid code modifications of the kernel by rogue code.
As the NX bits of all levels of translation entries are or-ed and the
RW bits of all levels are and-ed, looking just into the PTE isn't enough
for the decision that a writable page is executable, too.
When running as a Xen PV guest, the direct map PMDs and kernel high
map PMDs share the same set of PTEs. Xen kernel initialization will set
the NX bit in the direct map PMD entries, and not the shared PTEs.
Fixes: 652c5bf380 ("x86/mm: Refuse W^X violations")
Reported-by: Jason Andryuk <jandryuk@gmail.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20240412151258.9171-5-jgross@suse.com
Modify _lookup_address_cpa() to no longer use lookup_address(), but
only lookup_address_in_pgd().
This is done in preparation of using lookup_address_in_pgd_attr().
No functional change intended.
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20240412151258.9171-4-jgross@suse.com
Fix show_fault_oops() to not only look at the leaf PTE for detecting
NX violations, but to use the effective NX value returned by
lookup_address_in_pgd_attr() instead.
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20240412151258.9171-3-jgross@suse.com
Add lookup_address_in_pgd_attr() doing the same as the already
existing lookup_address_in_pgd(), but returning the effective settings
of the NX and RW bits of all walked page table levels, too.
This will be needed in order to match hardware behavior when looking
for effective access rights, especially for detecting writable code
pages.
In order to avoid code duplication, let lookup_address_in_pgd() call
lookup_address_in_pgd_attr() with dummy parameters.
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20240412151258.9171-2-jgross@suse.com
- Follow up fixes for the BHI mitigations code.
- Fix !SPECULATION_MITIGATIONS bug not turning off
mitigations as expected.
- Work around an APIC emulation bug when the kernel is built with
Clang and run as a SEV guest.
- Follow up x86 topology fixes.
Note that there's minor cleanups included in the BHI fixes,
which we'd normally delay to the next merge window, but the
BHI mitigations code is new and will be backported widely,
so we thought it would be better to have a unified codebase
at this stage. (Let me know if that assumption is wrong and
I'll rebase it.)
Signed-off-by: Ingo Molnar <mingo@kernel.org>
-----BEGIN PGP SIGNATURE-----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=2ig7
-----END PGP SIGNATURE-----
Merge tag 'x86-urgent-2024-04-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull misc x86 fixes from Ingo Molnar:
- Follow up fixes for the BHI mitigations code
- Fix !SPECULATION_MITIGATIONS bug not turning off mitigations as
expected
- Work around an APIC emulation bug when the kernel is built with Clang
and run as a SEV guest
- Follow up x86 topology fixes
* tag 'x86-urgent-2024-04-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/cpu/amd: Move TOPOEXT enablement into the topology parser
x86/cpu/amd: Make the NODEID_MSR union actually work
x86/cpu/amd: Make the CPUID 0x80000008 parser correct
x86/bugs: Replace CONFIG_SPECTRE_BHI_{ON,OFF} with CONFIG_MITIGATION_SPECTRE_BHI
x86/bugs: Remove CONFIG_BHI_MITIGATION_AUTO and spectre_bhi=auto
x86/bugs: Clarify that syscall hardening isn't a BHI mitigation
x86/bugs: Fix BHI handling of RRSBA
x86/bugs: Rename various 'ia32_cap' variables to 'x86_arch_cap_msr'
x86/bugs: Cache the value of MSR_IA32_ARCH_CAPABILITIES
x86/bugs: Fix BHI documentation
x86/cpu: Actually turn off mitigations by default for SPECULATION_MITIGATIONS=n
x86/topology: Don't update cpu_possible_map in topo_set_cpuids()
x86/bugs: Fix return type of spectre_bhi_state()
x86/apic: Force native_apic_mem_read() to use the MOV instruction
data in certain circumstances.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
-----BEGIN PGP SIGNATURE-----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=L86s
-----END PGP SIGNATURE-----
Merge tag 'perf-urgent-2024-04-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf event fix from Ingo Molnar:
"Fix the x86 PMU multi-counter code returning invalid data in certain
circumstances"
* tag 'perf-urgent-2024-04-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/x86: Fix out of range data
Confusingly, X86_FEATURE_RETPOLINE doesn't mean retpolines are enabled,
as it also includes the original "AMD retpoline" which isn't a retpoline
at all.
Also replace cpu_feature_enabled() with boot_cpu_has() because this is
before alternatives are patched and cpu_feature_enabled()'s fallback
path is slower than plain old boot_cpu_has().
Fixes: ec9404e40e ("x86/bhi: Add BHI mitigation knob")
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/ad3807424a3953f0323c011a643405619f2a4927.1712944776.git.jpoimboe@kernel.org
per-CPU SEV data is dominantly accessed from their own local CPUs,
so allocate them node-local to improve performance.
Signed-off-by: Li RongQing <lirongqing@baidu.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Nikunj A Dadhania <nikunj@amd.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Link: https://lore.kernel.org/r/20240412030130.49704-1-lirongqing@baidu.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
There's a new conflict between this commit pending in x86/cpu:
63edbaa48a x86/cpu/topology: Add support for the AMD 0x80000026 leaf
And these fixes in x86/urgent:
c064b536a8 x86/cpu/amd: Make the NODEID_MSR union actually work
1b3108f689 x86/cpu/amd: Make the CPUID 0x80000008 parser correct
Resolve them.
Conflicts:
arch/x86/kernel/cpu/topology_amd.c
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The topology rework missed that early_init_amd() tries to re-enable the
Topology Extensions when the BIOS disabled them.
The new parser is invoked before early_init_amd() so the re-enable attempt
happens too late.
Move it into the AMD specific topology parser code where it belongs.
Fixes: f7fb3b2dd9 ("x86/cpu: Provide an AMD/HYGON specific topology parser")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/878r1j260l.ffs@tglx
A system with NODEID_MSR was reported to crash during early boot without
any output.
The reason is that the union which is used for accessing the bitfields in
the MSR is written wrongly and the resulting executable code accesses the
wrong part of the MSR data.
As a consequence a later division by that value results in 0 and that
result is used for another division as divisor, which obviously does not
work well.
The magic world of C, unions and bitfields:
union {
u64 bita : 3,
bitb : 3;
u64 all;
} x;
x.all = foo();
a = x.bita;
b = x.bitb;
results in the effective executable code of:
a = b = x.bita;
because bita and bitb are treated as union members and therefore both end
up at bit offset 0.
Wrapping the bitfield into an anonymous struct:
union {
struct {
u64 bita : 3,
bitb : 3;
};
u64 all;
} x;
works like expected.
Rework the NODEID_MSR union in exactly that way to cure the problem.
Fixes: f7fb3b2dd9 ("x86/cpu: Provide an AMD/HYGON specific topology parser")
Reported-by: "kernelci.org bot" <bot@kernelci.org>
Reported-by: Laura Nao <laura.nao@collabora.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Laura Nao <laura.nao@collabora.com>
Link: https://lore.kernel.org/r/20240410194311.596282919@linutronix.de
Closes: https://lore.kernel.org/all/20240322175210.124416-1-laura.nao@collabora.com/
CPUID 0x80000008 ECX.cpu_nthreads describes the number of threads in the
package. The parser uses this value to initialize the SMT domain level.
That's wrong because cpu_nthreads does not describe the number of threads
per physical core. So this needs to set the CORE domain level and let the
later parsers set the SMT shift if available.
Preset the SMT domain level with the assumption of one thread per core,
which is correct ifrt here are no other CPUID leafs to parse, and propagate
cpu_nthreads and the core level APIC bitwidth into the CORE domain.
Fixes: f7fb3b2dd9 ("x86/cpu: Provide an AMD/HYGON specific topology parser")
Reported-by: "kernelci.org bot" <bot@kernelci.org>
Reported-by: Laura Nao <laura.nao@collabora.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Laura Nao <laura.nao@collabora.com>
Link: https://lore.kernel.org/r/20240410194311.535206450@linutronix.de
For consistency with the other CONFIG_MITIGATION_* options, replace the
CONFIG_SPECTRE_BHI_{ON,OFF} options with a single
CONFIG_MITIGATION_SPECTRE_BHI option.
[ mingo: Fix ]
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nikolay Borisov <nik.borisov@suse.com>
Link: https://lore.kernel.org/r/3833812ea63e7fdbe36bf8b932e63f70d18e2a2a.1712813475.git.jpoimboe@kernel.org
Unlike most other mitigations' "auto" options, spectre_bhi=auto only
mitigates newer systems, which is confusing and not particularly useful.
Remove it.
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Nikolay Borisov <nik.borisov@suse.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/412e9dc87971b622bbbaf64740ebc1f140bff343.1712813475.git.jpoimboe@kernel.org
x86 CMPXCHG instruction returns success in the ZF flag. Remove
redundant CMP instruction after CMPXCHG that performs the same check.
Also update the function comment to mention the modern version
of the equivalent C code.
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20240412083908.282802-1-ubizjak@gmail.com
TDX uses different ABI to get information about VM exit. Pass intr_info to
the NMI and INTR handlers instead of pulling it from vcpu_vmx in
preparation for sharing the bulk of the handlers with TDX.
When the guest TD exits to VMM, RAX holds status and exit reason, RCX holds
exit qualification etc rather than the VMCS fields because VMM doesn't have
access to the VMCS. The eventual code will be
VMX:
- get exit reason, intr_info, exit_qualification, and etc from VMCS
- call NMI/INTR handlers (common code)
TDX:
- get exit reason, intr_info, exit_qualification, and etc from guest
registers
- call NMI/INTR handlers (common code)
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <0396a9ae70d293c9d0b060349dae385a8a4fbcec.1705965635.git.isaku.yamahata@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM accesses Virtual Machine Control Structure (VMCS) with VMX instructions
to operate on VM. TDX doesn't allow VMM to operate VMCS directly.
Instead, TDX has its own data structures, and TDX SEAMCALL APIs for VMM to
indirectly operate those data structures. This means we must have a TDX
version of kvm_x86_ops.
The existing global struct kvm_x86_ops already defines an interface which
can be adapted to TDX, but kvm_x86_ops is a system-wide, not per-VM
structure. To allow VMX to coexist with TDs, the kvm_x86_ops callbacks
will have wrappers "if (tdx) tdx_op() else vmx_op()" to pick VMX or
TDX at run time.
To split the runtime switch, the VMX implementation, and the TDX
implementation, add main.c, and move out the vmx_x86_ops hooks in
preparation for adding TDX. Use 'vt' for the naming scheme as a nod to
VT-x and as a concatenation of VmxTdx.
The eventually converted code will look like this:
vmx.c:
vmx_op() { ... }
VMX initialization
tdx.c:
tdx_op() { ... }
TDX initialization
x86_ops.h:
vmx_op();
tdx_op();
main.c:
static vt_op() { if (tdx) tdx_op() else vmx_op() }
static struct kvm_x86_ops vt_x86_ops = {
.op = vt_op,
initialization functions call both VMX and TDX initialization
Opportunistically, fix the name inconsistency from vmx_create_vcpu() and
vmx_free_vcpu() to vmx_vcpu_create() and vmx_vcpu_free().
Co-developed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com>
Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Reviewed-by: Yuan Yao <yuan.yao@intel.com>
Message-Id: <e603c317587f933a9d1bee8728c84e4935849c16.1705965634.git.isaku.yamahata@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
By necessity, TDX will use a different register ABI for hypercalls.
Break out the core functionality so that it may be reused for TDX.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
Message-Id: <5134caa55ac3dec33fb2addb5545b52b3b52db02.1705965635.git.isaku.yamahata@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The idea that no parameter would ever be necessary when enabling SEV or
SEV-ES for a VM was decidedly optimistic. The first source of variability
that was encountered is the desired set of VMSA features, as that affects
the measurement of the VM's initial state and cannot be changed
arbitrarily by the hypervisor.
This series adds all the APIs that are needed to customize the features,
with room for future enhancements:
- a new /dev/kvm device attribute to retrieve the set of supported
features (right now, only debug swap)
- a new sub-operation for KVM_MEM_ENCRYPT_OP that can take a struct,
replacing the existing KVM_SEV_INIT and KVM_SEV_ES_INIT
It then puts the new op to work by including the VMSA features as a field
of the The existing KVM_SEV_INIT and KVM_SEV_ES_INIT use the full set of
supported VMSA features for backwards compatibility; but I am considering
also making them use zero as the feature mask, and will gladly adjust the
patches if so requested.
In order to avoid creating *two* new KVM_MEM_ENCRYPT_OPs, I decided that
I could as well make SEV and SEV-ES use VM types. This allows SEV-SNP
to reuse the KVM_SEV_INIT2 ioctl.
And while at it, KVM_SEV_INIT2 also includes two bugfixes. First of all,
SEV-ES VM, when created with the new VM type instead of KVM_SEV_ES_INIT,
reject KVM_GET_REGS/KVM_SET_REGS and friends on the vCPU file descriptor
once the VMSA has been encrypted... which is how the API should have
always behaved. Second, they also synchronize the FPU and AVX state.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Make the non-AVX implementation of AES-XTS (xts-aes-aesni) use the new
glue code that was introduced for the AVX implementations of AES-XTS.
This reduces code size, and it improves the performance of xts-aes-aesni
due to the optimization for messages that don't span page boundaries.
This required moving the new glue functions higher up in the file and
allowing the IV encryption function to be specified by the caller.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Since sha512_transform_rorx() uses ymm registers, execute vzeroupper
before returning from it. This is necessary to avoid reducing the
performance of SSE code.
Fixes: e01d69cb01 ("crypto: sha512 - Optimized SHA512 x86_64 assembly routine using AVX instructions.")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Acked-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Since sha256_transform_rorx() uses ymm registers, execute vzeroupper
before returning from it. This is necessary to avoid reducing the
performance of SSE code.
Fixes: d34a460092 ("crypto: sha256 - Optimized sha256 x86_64 routine using AVX2's RORX instructions")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Acked-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Since nh_avx2() uses ymm registers, execute vzeroupper before returning
from it. This is necessary to avoid reducing the performance of SSE
code.
Fixes: 0f961f9f67 ("crypto: x86/nhpoly1305 - add AVX2 accelerated NHPoly1305")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Acked-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
-----BEGIN PGP SIGNATURE-----
iQFHBAABCgAxFiEEIbPD0id6easf0xsudhRwX5BBoF4FAmYYYPkTHHdlaS5saXVA
a2VybmVsLm9yZwAKCRB2FHBfkEGgXnxhB/4/8c7lFT53VbujFmVA5sNvpP5Ji5Xg
ERhVID7tzDyaVRPr+tpPJIW0Oj/t34SH9seoTYCBCM/UABWe/Gxceg2JaoOzIx+l
LHi73T4BBaqExiXbCCFj8N7gLO5P4Xz6ZZRgwHws1KmMXsiWYmYsbv36eSv9x6qK
+z/n6p9/ubKFNj2/vsvfiGmY0XHayD3NM4Y4toMbYE/tuRT8uZ7D5sqWdRf+UhW/
goRDA5qppeSfuaQu2LNVoz1e6wRmeJFv8OHgaPvQqAjTRLzPwwss28HICmKc8gh3
HDDUUJCHSs1XItSGDFip6rIFso5X/ZHO0d6pV75hOKCisd7lV0qH6NIZ
=k62H
-----END PGP SIGNATURE-----
Merge tag 'hyperv-fixes-signed-20240411' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux
Pull hyperv fixes from Wei Liu:
- Some cosmetic changes (Erni Sri Satya Vennela, Li Zhijian)
- Introduce hv_numa_node_to_pxm_info() (Nuno Das Neves)
- Fix KVP daemon to handle IPv4 and IPv6 combination for keyfile format
(Shradha Gupta)
- Avoid freeing decrypted memory in a confidential VM (Rick Edgecombe
and Michael Kelley)
* tag 'hyperv-fixes-signed-20240411' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
Drivers: hv: vmbus: Don't free ring buffers that couldn't be re-encrypted
uio_hv_generic: Don't free decrypted memory
hv_netvsc: Don't free decrypted memory
Drivers: hv: vmbus: Track decrypted status in vmbus_gpadl
Drivers: hv: vmbus: Leak pages if set_memory_encrypted() fails
hv/hv_kvp_daemon: Handle IPv4 and Ipv6 combination for keyfile format
hv: vmbus: Convert sprintf() family to sysfs_emit() family
mshyperv: Introduce hv_numa_node_to_pxm_info()
x86/hyperv: Cosmetic changes for hv_apic.c
Drop the "If AD bits are enabled/disabled" verbiage from the comments
above kvm_tdp_mmu_clear_dirty_{slot,pt_masked}() since TDP MMU SPTEs may
need to be write-protected even when A/D bits are enabled. i.e. These
comments aren't technically correct.
No functional change intended.
Signed-off-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20240315230541.1635322-4-dmatlack@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Drop the comments above clear_dirty_gfn_range() and
clear_dirty_pt_masked(), since each is word-for-word identical to the
comment above their parent function.
Leave the comment on the parent functions since they are APIs called by
the KVM/x86 MMU.
No functional change intended.
Signed-off-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20240315230541.1635322-3-dmatlack@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Check kvm_mmu_page_ad_need_write_protect() when deciding whether to
write-protect or clear D-bits on TDP MMU SPTEs, so that the TDP MMU
accounts for any role-specific reasons for disabling D-bit dirty logging.
Specifically, TDP MMU SPTEs must be write-protected when the TDP MMU is
being used to run an L2 (i.e. L1 has disabled EPT) and PML is enabled.
KVM always disables PML when running L2, even when L1 and L2 GPAs are in
the some domain, so failing to write-protect TDP MMU SPTEs will cause
writes made by L2 to not be reflected in the dirty log.
Reported-by: syzbot+900d58a45dcaab9e4821@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=900d58a45dcaab9e4821
Fixes: 5982a53926 ("KVM: x86/mmu: Use kvm_ad_enabled() to determine if TDP MMU SPTEs need wrprot")
Cc: stable@vger.kernel.org
Cc: Vipin Sharma <vipinsh@google.com>
Cc: Sean Christopherson <seanjc@google.com>
Signed-off-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20240315230541.1635322-2-dmatlack@google.com
[sean: massage shortlog and changelog, tweak ternary op formatting]
Signed-off-by: Sean Christopherson <seanjc@google.com>
Set kvm_mmu_page_role.invalid to mark the various MMU root_roles invalid
during CPUID update in order to force a refresh, instead of zeroing out
the entire role. This fixes a bug where kvm_mmu_free_roots() incorrectly
thinks a root is indirect, i.e. not a TDP MMU, due to "direct" being
zeroed, which in turn causes KVM to take mmu_lock for write instead of
read.
Note, paving over the entire role was largely unintentional, commit
7a458f0e1b ("KVM: x86/mmu: remove extended bits from mmu_role, rename
field") simply missed that "invalid" could be set.
Fixes: 576a15de8d ("KVM: x86/mmu: Free TDP MMU roots while holding mmy_lock for read")
Reported-by: syzbot+dc308fcfcd53f987de73@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/0000000000009b38080614c49bdb@google.com
Cc: Phi Nguyen <phind.uet@gmail.com>
Link: https://lore.kernel.org/r/20240408231115.1387279-1-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Disable LBR virtualization if the CPU doesn't support callstacks, which
were introduced in HSW (see commit e9d7f7cd97 ("perf/x86/intel: Add
basic Haswell LBR call stack support"), as KVM unconditionally configures
the perf LBR event with PERF_SAMPLE_BRANCH_CALL_STACK, i.e. LBR
virtualization always fails on pre-HSW CPUs.
Simply disable LBR support on such CPUs, as it has never worked, i.e.
there is no risk of breaking an existing setup, and figuring out a way
to performantly context switch LBRs on old CPUs is not worth the effort.
Fixes: be635e34c2 ("KVM: vmx/pmu: Expose LBR_FMT in the MSR_IA32_PERF_CAPABILITIES")
Cc: Mingwei Zhang <mizhang@google.com>
Cc: Jim Mattson <jmattson@google.com>
Tested-by: Mingwei Zhang <mizhang@google.com>
Link: https://lore.kernel.org/r/20240307011344.835640-4-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Add a "has_callstack" field to the x86_pmu_lbr structure used to pass
information to KVM, and set it accordingly in x86_perf_get_lbr(). KVM
will use has_callstack to avoid trying to create perf LBR events with
PERF_SAMPLE_BRANCH_CALL_STACK on CPUs that don't support callstacks.
Reviewed-by: Mingwei Zhang <mizhang@google.com>
Link: https://lore.kernel.org/r/20240307011344.835640-3-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Snapshot VMX's LBR capabilities once during module initialization instead
of calling into perf every time a vCPU reconfigures its vPMU. This will
allow massaging the LBR capabilities, e.g. if the CPU doesn't support
callstacks, without having to remember to update multiple locations.
Opportunistically tag vmx_get_perf_capabilities() with __init, as it's
only called from vmx_set_cpu_caps().
Reviewed-by: Mingwei Zhang <mizhang@google.com>
Link: https://lore.kernel.org/r/20240307011344.835640-2-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
The .change_pte() MMU notifier callback was intended as an
optimization. The original point of it was that KSM could tell KVM to flip
its secondary PTE to a new location without having to first zap it. At
the time there was also an .invalidate_page() callback; both of them were
*not* bracketed by calls to mmu_notifier_invalidate_range_{start,end}(),
and .invalidate_page() also doubled as a fallback implementation of
.change_pte().
Later on, however, both callbacks were changed to occur within an
invalidate_range_start/end() block.
In the case of .change_pte(), commit 6bdb913f0a ("mm: wrap calls to
set_pte_at_notify with invalidate_range_start and invalidate_range_end",
2012-10-09) did so to remove the fallback from .invalidate_page() to
.change_pte() and allow sleepable .invalidate_page() hooks.
This however made KVM's usage of the .change_pte() callback completely
moot, because KVM unmaps the sPTEs during .invalidate_range_start()
and therefore .change_pte() has no hope of finding a sPTE to change.
Drop the generic KVM code that dispatches to kvm_set_spte_gfn(), as
well as all the architecture specific implementations.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Anup Patel <anup@brainfault.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Reviewed-by: Bibo Mao <maobibo@loongson.cn>
Message-ID: <20240405115815.3226315-2-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The DebugSwap feature of SEV-ES provides a way for confidential guests
to use data breakpoints. Its status is record in VMSA, and therefore
attestation signatures depend on whether it is enabled or not. In order
to avoid invalidating the signatures depending on the host machine, it
was disabled by default (see commit 5abf6dceb0, "SEV: disable SEV-ES
DebugSwap by default", 2024-03-09).
However, we now have a new API to create SEV VMs that allows enabling
DebugSwap based on what the user tells KVM to do, and we also changed the
legacy KVM_SEV_ES_INIT API to never enable DebugSwap. It is therefore
possible to re-enable the feature without breaking compatibility with
kernels that pre-date the introduction of DebugSwap, so go ahead.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20240404121327.3107131-14-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The idea that no parameter would ever be necessary when enabling SEV or
SEV-ES for a VM was decidedly optimistic. In fact, in some sense it's
already a parameter whether SEV or SEV-ES is desired. Another possible
source of variability is the desired set of VMSA features, as that affects
the measurement of the VM's initial state and cannot be changed
arbitrarily by the hypervisor.
Create a new sub-operation for KVM_MEMORY_ENCRYPT_OP that can take a struct,
and put the new op to work by including the VMSA features as a field of the
struct. The existing KVM_SEV_INIT and KVM_SEV_ES_INIT use the full set of
supported VMSA features for backwards compatibility.
The struct also includes the usual bells and whistles for future
extensibility: a flags field that must be zero for now, and some padding
at the end.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20240404121327.3107131-13-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
SEV-ES allows passing custom contents for x87, SSE and AVX state into the VMSA.
Allow userspace to do that with the usual KVM_SET_XSAVE API and only mark
FPU contents as confidential after it has been copied and encrypted into
the VMSA.
Since the XSAVE state for AVX is the first, it does not need the
compacted-state handling of get_xsave_addr(). However, there are other
parts of XSAVE state in the VMSA that currently are not handled, and
the validation logic of get_xsave_addr() is pointless to duplicate
in KVM, so move get_xsave_addr() to public FPU API; it is really just
a facility to operate on XSAVE state and does not expose any internal
details of arch/x86/kernel/fpu.
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20240404121327.3107131-12-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20240404121327.3107131-11-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20240404121327.3107131-10-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This simplifies the implementation of KVM_CHECK_EXTENSION(KVM_CAP_VM_TYPES),
and also allows the vendor module to specify which VM types are supported.
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20240404121327.3107131-9-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Some VM types have characteristics in common; in fact, the only use
of VM types right now is kvm_arch_has_private_mem and it assumes that
_all_ nonzero VM types have private memory.
We will soon introduce a VM type for SEV and SEV-ES VMs, and at that
point we will have two special characteristics of confidential VMs
that depend on the VM type: not just if memory is private, but
also whether guest state is protected. For the latter we have
kvm->arch.guest_state_protected, which is only set on a fully initialized
VM.
For VM types with protected guest state, we can actually fix a problem in
the SEV-ES implementation, where ioctls to set registers do not cause an
error even if the VM has been initialized and the guest state encrypted.
Make sure that when using VM types that will become an error.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20240209183743.22030-7-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Isaku Yamahata <isaku.yamahata@intel.com>
Message-ID: <20240404121327.3107131-8-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Right now, the set of features that are stored in the VMSA upon
initialization is fixed and depends on the module parameters for
kvm-amd.ko. However, the hypervisor cannot really change it at will
because the feature word has to match between the hypervisor and whatever
computes a measurement of the VMSA for attestation purposes.
Add a field to kvm_sev_info that holds the set of features to be stored
in the VMSA; and query it instead of referring to the module parameters.
Because KVM_SEV_INIT and KVM_SEV_ES_INIT accept no parameters, this
does not yet introduce any functional change, but it paves the way for
an API that allows customization of the features per-VM.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20240209183743.22030-6-pbonzini@redhat.com>
Reviewed-by: Michael Roth <michael.roth@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20240404121327.3107131-7-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Compute the set of features to be stored in the VMSA when KVM is
initialized; move it from there into kvm_sev_info when SEV is initialized,
and then into the initial VMSA.
The new variable can then be used to return the set of supported features
to userspace, via the KVM_GET_DEVICE_ATTR ioctl.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Isaku Yamahata <isaku.yamahata@intel.com>
Message-ID: <20240404121327.3107131-6-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Allow vendor modules to provide their own attributes on /dev/kvm.
To avoid proliferation of vendor ops, implement KVM_HAS_DEVICE_ATTR
and KVM_GET_DEVICE_ATTR in terms of the same function. You're not
supposed to use KVM_GET_DEVICE_ATTR to do complicated computations,
especially on /dev/kvm.
Reviewed-by: Michael Roth <michael.roth@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Isaku Yamahata <isaku.yamahata@intel.com>
Message-ID: <20240404121327.3107131-5-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
There is no danger to the kernel if 32-bit userspace provides a 64-bit
value that has the high bits set, but for whatever reason happens to
resolve to an address that has something mapped there. KVM uses the
checked version of get_user() and put_user(), so any faults are caught
properly.
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20240404121327.3107131-4-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Stop compiling sev.c when CONFIG_KVM_AMD_SEV=n, as the number of #ifdefs
in sev.c is getting ridiculous, and having #ifdefs inside of SEV helpers
is quite confusing.
To minimize #ifdefs in code flows, #ifdef away only the kvm_x86_ops hooks
and the #VMGEXIT handler. Stubs are also restricted to functions that
check sev_enabled and to the destruction functions sev_free_cpu() and
sev_vm_destroy(), where the style of their callers is to leave checks
to the callers. Most call sites instead rely on dead code elimination
to take care of functions that are guarded with sev_guest() or
sev_es_guest().
Signed-off-by: Sean Christopherson <seanjc@google.com>
Co-developed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20240404121327.3107131-3-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Leave SEV and SEV_ES '0' in kvm_cpu_caps by default, and instead set them
in sev_set_cpu_caps() if SEV and SEV-ES support are fully enabled. Aside
from the fact that sev_set_cpu_caps() is wildly misleading when it *clears*
capabilities, this will allow compiling out sev.c without falsely
advertising SEV/SEV-ES support in KVM_GET_SUPPORTED_CPUID.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Michael Roth <michael.roth@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20240404121327.3107131-2-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
On AMD and Hygon platforms, the local APIC does not automatically set
the mask bit of the LVTPC register when handling a PMI and there is
no need to clear it in the kernel's PMI handler.
For guests, the mask bit is currently set by kvm_apic_local_deliver()
and unless it is cleared by the guest kernel's PMI handler, PMIs stop
arriving and break use-cases like sampling with perf record.
This does not affect non-PerfMonV2 guests because PMIs are handled in
the guest kernel by x86_pmu_handle_irq() which always clears the LVTPC
mask bit irrespective of the vendor.
Before:
$ perf record -e cycles:u true
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.001 MB perf.data (1 samples) ]
After:
$ perf record -e cycles:u true
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.002 MB perf.data (19 samples) ]
Fixes: a16eb25b09 ("KVM: x86: Mask LVTPC when handling a PMI")
Cc: stable@vger.kernel.org
Signed-off-by: Sandipan Das <sandipan.das@amd.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
[sean: use is_intel_compatible instead of !is_amd_or_hygon()]
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-ID: <20240405235603.1173076-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add kvm_vcpu_arch.is_amd_compatible to cache if a vCPU's vendor model is
compatible with AMD, i.e. if the vCPU vendor is AMD or Hygon, along with
helpers to check if a vCPU is compatible AMD vs. Intel. To handle Intel
vs. AMD behavior related to masking the LVTPC entry, KVM will need to
check for vendor compatibility on every PMI injection, i.e. querying for
AMD will soon be a moderately hot path.
Note! This subtly (or maybe not-so-subtly) makes "Intel compatible" KVM's
default behavior, both if userspace omits (or never sets) CPUID 0x0 and if
userspace sets a completely unknown vendor. One could argue that KVM
should treat such vCPUs as not being compatible with Intel *or* AMD, but
that would add useless complexity to KVM.
KVM needs to do *something* in the face of vendor specific behavior, and
so unless KVM conjured up a magic third option, choosing to treat unknown
vendors as neither Intel nor AMD means that checks on AMD compatibility
would yield Intel behavior, and checks for Intel compatibility would yield
AMD behavior. And that's far worse as it would effectively yield random
behavior depending on whether KVM checked for AMD vs. Intel vs. !AMD vs.
!Intel. And practically speaking, all x86 CPUs follow either Intel or AMD
architecture, i.e. "supporting" an unknown third architecture adds no
value.
Deliberately don't convert any of the existing guest_cpuid_is_intel()
checks, as the Intel side of things is messier due to some flows explicitly
checking for exactly vendor==Intel, versus some flows assuming anything
that isn't "AMD compatible" gets Intel behavior. The Intel code will be
cleaned up in the future.
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-ID: <20240405235603.1173076-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The early 64-bit boot code must be entered with a 1:1 mapping of the
bootable image, but it cannot operate without a 1:1 mapping of all the
assets in memory that it accesses, and therefore, it creates such
mappings for all known assets upfront, and additional ones on demand
when a page fault happens on a memory address.
These mappings are created with the global bit G set, as the flags used
to create page table descriptors are based on __PAGE_KERNEL_LARGE_EXEC
defined by the core kernel, even though the context where these mappings
are used is very different.
This means that the TLB maintenance carried out by the decompressor is
not sufficient if it is entered with CR4.PGE enabled, which has been
observed to happen with the stage0 bootloader of project Oak. While this
is a dubious practice if no global mappings are being used to begin
with, the decompressor is clearly at fault here for creating global
mappings and not performing the appropriate TLB maintenance.
Since commit:
f97b67a773 ("x86/decompressor: Only call the trampoline when changing paging levels")
CR4 is no longer modified by the decompressor if no change in the number
of paging levels is needed. Before that, CR4 would always be set to a
consistent value with PGE cleared.
So let's reinstate a simplified version of the original logic to put CR4
into a known state, and preserve the PAE, MCE and LA57 bits, none of
which can be modified freely at this point (PAE and LA57 cannot be
changed while running in long mode, and MCE cannot be cleared when
running under some hypervisors).
This effectively clears PGE and works around the project Oak bug.
Fixes: f97b67a773 ("x86/decompressor: Only call the trampoline when ...")
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lore.kernel.org/r/20240410151354.506098-2-ardb+git@google.com
-----BEGIN PGP SIGNATURE-----
iQFSBAABCAA8FiEEq68RxlopcLEwq+PEeb4+QwBBGIYFAmYTAJYeHHRvcnZhbGRz
QGxpbnV4LWZvdW5kYXRpb24ub3JnAAoJEHm+PkMAQRiG2bEH/jOBXd0ZCz+s9+F4
TbSvDEE8UjitQdEJ5WSBY9CEvFI8OuVQr23gYPUn+gfgqLX0Vsp8HfxL6bBP5Tj6
DSzAkwF/mvIfa6VLFmO1GmvyhYtmWkmbM825tNqKHSNTBc9cCLH3H+780wNtTMwQ
VkB8O3KS/wZBGKSbFfiXW+fT3SkWIMLtdBAaox+vcxHXpiluXxSbxANRD5kTbdG0
UAW9S4+3A0jNk/KeXEvJDqkf7C3ASsjtNPbK+gFDfOXxdNYFTC2IUf93rL61VB4s
C2rtUklcLE8gFDtvkQ8JtGWmDj4pWPEDIyhICKlzP/aKCjXcNzLaoM0GJQYJS+PN
aNevw24=
=318J
-----END PGP SIGNATURE-----
Merge tag 'v6.9-rc3' into x86/boot, to pick up fixes before queueing up more changes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
While syscall hardening helps prevent some BHI attacks, there's still
other low-hanging fruit remaining. Don't classify it as a mitigation
and make it clear that the system may still be vulnerable if it doesn't
have a HW or SW mitigation enabled.
Fixes: ec9404e40e ("x86/bhi: Add BHI mitigation knob")
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/b5951dae3fdee7f1520d5136a27be3bdfe95f88b.1712813475.git.jpoimboe@kernel.org
The ARCH_CAP_RRSBA check isn't correct: RRSBA may have already been
disabled by the Spectre v2 mitigation (or can otherwise be disabled by
the BHI mitigation itself if needed). In that case retpolines are fine.
Fixes: ec9404e40e ("x86/bhi: Add BHI mitigation knob")
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/6f56f13da34a0834b69163467449be7f58f253dc.1712813475.git.jpoimboe@kernel.org
So we are using the 'ia32_cap' value in a number of places,
which got its name from MSR_IA32_ARCH_CAPABILITIES MSR register.
But there's very little 'IA32' about it - this isn't 32-bit only
code, nor does it originate from there, it's just a historic
quirk that many Intel MSR names are prefixed with IA32_.
This is already clear from the helper method around the MSR:
x86_read_arch_cap_msr(), which doesn't have the IA32 prefix.
So rename 'ia32_cap' to 'x86_arch_cap_msr' to be consistent with
its role and with the naming of the helper function.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Nikolay Borisov <nik.borisov@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/9592a18a814368e75f8f4b9d74d3883aa4fd1eaf.1712813475.git.jpoimboe@kernel.org
There's no need to keep reading MSR_IA32_ARCH_CAPABILITIES over and
over. It's even read in the BHI sysfs function which is a big no-no.
Just read it once and cache it.
Fixes: ec9404e40e ("x86/bhi: Add BHI mitigation knob")
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Nikolay Borisov <nik.borisov@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/9592a18a814368e75f8f4b9d74d3883aa4fd1eaf.1712813475.git.jpoimboe@kernel.org
topo_set_cpuids() updates cpu_present_map and cpu_possible map. It is
invoked during enumeration and "physical hotplug" operations. In the
latter case this results in a kernel crash because cpu_possible_map is
marked read only after init completes.
There is no reason to update cpu_possible_map in that function. During
enumeration cpu_possible_map is not relevant and gets fully initialized
after enumeration completed. On "physical hotplug" the bit is already set
because the kernel allows only CPUs to be plugged which have been
enumerated and associated to a CPU number during early boot.
Remove the bogus update of cpu_possible_map.
Fixes: 0e53e7b656 ("x86/cpu/topology: Sanitize the APIC admission logic")
Reported-by: Jonathan Cameron <Jonathan.Cameron@Huawei.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/87ttkc6kwx.ffs@tglx
There is no need to implement arch_atomic_sub() family of inline
functions, corresponding macros can be directly implemented using
arch_atomic_add() inlines with negated argument.
No functional changes intended.
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20240410062957.322614-4-ubizjak@gmail.com
Introduce arch_atomic64_read_nonatomic() for 32-bit targets to load
the value from atomic64_t location in a non-atomic way. This
function is intended to be used in cases where a subsequent atomic
operation will handle the torn value, and can be used to prime the
first iteration of unconditional try_cmpxchg() loops.
Suggested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20240410062957.322614-2-ubizjak@gmail.com
The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is ignored (apart
from emitting a warning) and this typically results in resource leaks.
To improve here there is a quest to make the remove callback return
void. In the first step of this quest all drivers are converted to
.remove_new(), which already returns void. Eventually after all drivers
are converted, .remove_new() will be renamed to .remove().
Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/63c9d1e6b07296916e4218c63f59a2dd6c6b6b16.1712732665.git.u.kleine-koenig@pengutronix.de
The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is ignored (apart
from emitting a warning) and this typically results in resource leaks.
To improve here there is a quest to make the remove callback return
void. In the first step of this quest all drivers are converted to
.remove_new(), which already returns void. Eventually after all drivers
are converted, .remove_new() will be renamed to .remove().
Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/c7d669d8b0c994c77fb4c3bc7bec78aeb8659c74.1712732665.git.u.kleine-koenig@pengutronix.de
The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is ignored (apart
from emitting a warning) and this typically results in resource leaks.
To improve here there is a quest to make the remove callback return
void. In the first step of this quest all drivers are converted to
.remove_new(), which already returns void. Eventually after all drivers
are converted, .remove_new() will be renamed to .remove().
Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/adb9b0aca77d7aa8e54d0a664a4ee290834a60a1.1712732665.git.u.kleine-koenig@pengutronix.de
The definition of spectre_bhi_state() incorrectly returns a const char
* const. This causes the a compiler warning when building with W=1:
warning: type qualifiers ignored on function return type [-Wignored-qualifiers]
2812 | static const char * const spectre_bhi_state(void)
Remove the const qualifier from the pointer.
Fixes: ec9404e40e ("x86/bhi: Add BHI mitigation knob")
Reported-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20240409230806.1545822-1-daniel.sneddon@linux.intel.com
In smp_prepare_cpus_common() and x2apic_prepare_cpu():
- use 'cpu' instead of 'i'
- use 'node' instead of 'n'
- use vertical alignment to improve readability
- better structure basic blocks
- reduce col80 checkpatch damage
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: linux-kernel@vger.kernel.org
per-CPU cpumasks are dominantly accessed from their own local CPUs,
so allocate them node-local to improve performance.
[ mingo: Rewrote the changelog. ]
Signed-off-by: Li RongQing <lirongqing@baidu.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20240410030114.6201-1-lirongqing@baidu.com
On x86 each struct cpu_hw_events maintains a table for counter assignment but
it missed to update one for the deleted event in x86_pmu_del(). This
can make perf_clear_dirty_counters() reset used counter if it's called
before event scheduling or enabling. Then it would return out of range
data which doesn't make sense.
The following code can reproduce the problem.
$ cat repro.c
#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <linux/perf_event.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <sys/syscall.h>
struct perf_event_attr attr = {
.type = PERF_TYPE_HARDWARE,
.config = PERF_COUNT_HW_CPU_CYCLES,
.disabled = 1,
};
void *worker(void *arg)
{
int cpu = (long)arg;
int fd1 = syscall(SYS_perf_event_open, &attr, -1, cpu, -1, 0);
int fd2 = syscall(SYS_perf_event_open, &attr, -1, cpu, -1, 0);
void *p;
do {
ioctl(fd1, PERF_EVENT_IOC_ENABLE, 0);
p = mmap(NULL, 4096, PROT_READ, MAP_SHARED, fd1, 0);
ioctl(fd2, PERF_EVENT_IOC_ENABLE, 0);
ioctl(fd2, PERF_EVENT_IOC_DISABLE, 0);
munmap(p, 4096);
ioctl(fd1, PERF_EVENT_IOC_DISABLE, 0);
} while (1);
return NULL;
}
int main(void)
{
int i;
int n = sysconf(_SC_NPROCESSORS_ONLN);
pthread_t *th = calloc(n, sizeof(*th));
for (i = 0; i < n; i++)
pthread_create(&th[i], NULL, worker, (void *)(long)i);
for (i = 0; i < n; i++)
pthread_join(th[i], NULL);
free(th);
return 0;
}
And you can see the out of range data using perf stat like this.
Probably it'd be easier to see on a large machine.
$ gcc -o repro repro.c -pthread
$ ./repro &
$ sudo perf stat -A -I 1000 2>&1 | awk '{ if (length($3) > 15) print }'
1.001028462 CPU6 196,719,295,683,763 cycles # 194290.996 GHz (71.54%)
1.001028462 CPU3 396,077,485,787,730 branch-misses # 15804359784.80% of all branches (71.07%)
1.001028462 CPU17 197,608,350,727,877 branch-misses # 14594186554.56% of all branches (71.22%)
2.020064073 CPU4 198,372,472,612,140 cycles # 194681.113 GHz (70.95%)
2.020064073 CPU6 199,419,277,896,696 cycles # 195720.007 GHz (70.57%)
2.020064073 CPU20 198,147,174,025,639 cycles # 194474.654 GHz (71.03%)
2.020064073 CPU20 198,421,240,580,145 stalled-cycles-frontend # 100.14% frontend cycles idle (70.93%)
3.037443155 CPU4 197,382,689,923,416 cycles # 194043.065 GHz (71.30%)
3.037443155 CPU20 196,324,797,879,414 cycles # 193003.773 GHz (71.69%)
3.037443155 CPU5 197,679,956,608,205 stalled-cycles-backend # 1315606428.66% backend cycles idle (71.19%)
3.037443155 CPU5 198,571,860,474,851 instructions # 13215422.58 insn per cycle
It should move the contents in the cpuc->assign as well.
Fixes: 5471eea5d3 ("perf/x86: Reset the dirty counter to prevent the leak for an RDPMC task")
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Kan Liang <kan.liang@linux.intel.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240306061003.1894224-1-namhyung@kernel.org
commit 37b2a6510a48("KVM: use __vcalloc for very large allocations")
replaced kvzalloc()/kvcalloc() with vcalloc(), but didn't replace kvfree()
with vfree().
Signed-off-by: Li RongQing <lirongqing@baidu.com>
Link: https://lore.kernel.org/r/20240131012357.53563-1-lirongqing@baidu.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Use the GuestPhysBits field in CPUID.0x80000008 to communicate the max
mappable GPA to userspace, i.e. the max GPA that is addressable by the
CPU itself. Typically this is identical to the max effective GPA, except
in the case where the CPU supports MAXPHYADDR > 48 but does not support
5-level TDP (the CPU consults bits 51:48 of the GPA only when walking the
fifth level TDP page table entry).
Enumerating the max mappable GPA via CPUID will allow guest firmware to
map resources like PCI bars in the highest possible address space, while
ensuring that the GPA is addressable by the CPU. Without precise
knowledge about the max mappable GPA, the guest must assume that 5-level
paging is unsupported and thus restrict its mappings to the lower 48 bits.
Advertise the max mappable GPA via KVM_GET_SUPPORTED_CPUID as userspace
doesn't have easy access to whether or not 5-level paging is supported,
and to play nice with userspace VMMs that reflect the supported CPUID
directly into the guest.
AMD's APM (3.35) defines GuestPhysBits (EAX[23:16]) as:
Maximum guest physical address size in bits. This number applies
only to guests using nested paging. When this field is zero, refer
to the PhysAddrSize field for the maximum guest physical address size.
Tom Lendacky confirmed that the purpose of GuestPhysBits is software use
and KVM can use it as described above. Real hardware always returns zero.
Leave GuestPhysBits as '0' when TDP is disabled in order to comply with
the APM's statement that GuestPhysBits "applies only to guest using nested
paging". As above, guest firmware will likely create suboptimal mappings,
but that is a very minor issue and not a functional concern.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Link: https://lore.kernel.org/r/20240313125844.912415-3-kraxel@redhat.com
[sean: massage changelog]
Signed-off-by: Sean Christopherson <seanjc@google.com>
Drop KVM's propagation of GuestPhysBits (CPUID leaf 80000008, EAX[23:16])
to HostPhysBits (same leaf, EAX[7:0]) when advertising the address widths
to userspace via KVM_GET_SUPPORTED_CPUID.
Per AMD, GuestPhysBits is intended for software use, and physical CPUs do
not set that field. I.e. GuestPhysBits will be non-zero if and only if
KVM is running as a nested hypervisor, and in that case, GuestPhysBits is
NOT guaranteed to capture the CPU's effective MAXPHYADDR when running with
TDP enabled.
E.g. KVM will soon use GuestPhysBits to communicate the CPU's maximum
*addressable* guest physical address, which would result in KVM under-
reporting PhysBits when running as an L1 on a CPU with MAXPHYADDR=52,
but without 5-level paging.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Cc: stable@vger.kernel.org
Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Link: https://lore.kernel.org/r/20240313125844.912415-2-kraxel@redhat.com
[sean: rewrite changelog with --verbose, Cc stable@]
Signed-off-by: Sean Christopherson <seanjc@google.com>
Add a WARN_ON_ONCE() sanity check to verify that a nested PML Full VM-Exit
is only synthesized when the original VM-Exit from L2 was an EPT Violation.
While KVM can fallthrough to kvm_mmu_do_page_fault() if an EPT Misconfig
occurs on a stale MMIO SPTE, KVM should not treat the access as a write
(there isn't enough information to know *what* the access was), i.e. KVM
should never try to insert a PML entry in that case.
Link: https://lore.kernel.org/r/20240209221700.393189-4-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Move the exit_qualification field that is used to track information about
in-flight nEPT violations from "struct kvm_vcpu_arch" to "x86_exception",
i.e. associate the information with the actual nEPT violation instead of
the vCPU. To handle bits that are pulled from vmcs.EXIT_QUALIFICATION,
i.e. that are propagated from the "original" EPT violation VM-Exit, simply
grab them from the VMCS on-demand when injecting a nEPT Violation or a PML
Full VM-exit.
Aside from being ugly, having an exit_qualification field in kvm_vcpu_arch
is outright dangerous, e.g. see commit d7f0a00e43 ("KVM: VMX: Report
up-to-date exit qualification to userspace").
Opportunstically add a comment to call out that PML Full and EPT Violation
VM-Exits use the same bit to report NMI blocking information.
Link: https://lore.kernel.org/r/20240209221700.393189-3-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Explicitly clear the EXIT_QUALIFCATION field when injecting an EPT
misconfig into L1, as required by the VMX architecture. Per the SDM:
This field is saved for VM exits due to the following causes:
debug exceptions; page-fault exceptions; start-up IPIs (SIPIs);
system-management interrupts (SMIs) that arrive immediately after the
execution of I/O instructions; task switches; INVEPT; INVLPG; INVPCID;
INVVPID; LGDT; LIDT; LLDT; LTR; SGDT; SIDT; SLDT; STR; VMCLEAR; VMPTRLD;
VMPTRST; VMREAD; VMWRITE; VMXON; WBINVD; WBNOINVD; XRSTORS; XSAVES;
control-register accesses; MOV DR; I/O instructions; MWAIT; accesses to
the APIC-access page; EPT violations; EOI virtualization; APIC-write
emulation; page-modification log full; SPP-related events; and
instruction timeout. For all other VM exits, this field is cleared.
Generating EXIT_QUALIFICATION from vcpu->arch.exit_qualification is wrong
for all (two) paths that lead to nested_ept_inject_page_fault(). For EPT
violations (the common case), vcpu->arch.exit_qualification will have been
set by handle_ept_violation() to vmcs02.EXIT_QUALIFICATION, i.e. contains
the information of a EPT violation and thus is likely non-zero.
For an EPT misconfig, which can reach FNAME(walk_addr_generic) and thus
inject a nEPT misconfig if KVM created an MMIO SPTE that became stale,
vcpu->arch.exit_qualification will hold the information from the last EPT
violation VM-Exit, as vcpu->arch.exit_qualification is _only_ written by
handle_ept_violation().
Fixes: 4704d0befb ("KVM: nVMX: Exiting from L2 to L1")
Link: https://lore.kernel.org/r/20240209221700.393189-2-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Support atomics in bpf_arena that can be JITed as a single x86 instruction.
Instructions that are JITed as loops are not supported at the moment,
since they require more complex extable and loop logic.
JITs can choose to do smarter things with bpf_jit_supports_insn().
Like arm64 may decide to support all bpf atomics instructions
when emit_lse_atomic is available and none in ll_sc mode.
bpf_jit_supports_percpu_insn(), bpf_jit_supports_ptr_xchg() and
other such callbacks can be replaced with bpf_jit_supports_insn()
in the future.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20240405231134.17274-1-alexei.starovoitov@gmail.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Stop compiling vmenter.S with OBJECT_FILES_NON_STANDARD to skip objtool's
stack validation now that __svm_vcpu_run() and __svm_sev_es_vcpu_run()
create stack frames (though the former's effectiveness is dubious).
Note, due to a quirk in how OBJECT_FILES_NON_STANDARD was handled by the
build system prior to commit bf48d9b756 ("kbuild: change tool coverage
variables to take the path relative to $(obj)"), vmx/vmenter.S got lumped
in with svm/vmenter.S. __vmx_vcpu_run() already plays nice with frame
pointers, i.e. it was collateral damage when commit 7f4b5cde24 ("kvm:
Disable objtool frame pointer checking for vmenter.S") added the
OBJECT_FILES_NON_STANDARD hack-a-fix.
Link: https://lore.kernel.org/all/20240217055504.2059803-1-masahiroy@kernel.org
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lore.kernel.org/r/20240223204233.3337324-9-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Now that KVM uses the host save area to context switch RBP, i.e.
preserves RBP for the entirety of __svm_sev_es_vcpu_run(), create a stack
frame using the standared FRAME_{BEGIN,END} macros.
Note, __svm_sev_es_vcpu_run() is subtly not a leaf function as it can call
into ibpb_feature() via UNTRAIN_RET_VM.
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lore.kernel.org/r/20240223204233.3337324-8-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Use the host save area to preserve volatile registers that are used in
__svm_sev_es_vcpu_run() to access function parameters after #VMEXIT.
Like saving/restoring non-volatile registers, there's no reason not to
take advantage of hardware restoring registers on #VMEXIT, as doing so
shaves a few instructions and the save area is going to be accessed no
matter what.
Converting all register save/restore code to use the host save area also
make it easier to follow the SEV-ES VMRUN flow in its entirety, as
opposed to having a mix of stack-based versus host save area save/restore.
Add a parameter to RESTORE_HOST_SPEC_CTRL_BODY so that the SEV-ES path
doesn't need to write @spec_ctrl_intercepted to memory just to play nice
with the common macro.
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lore.kernel.org/r/20240223204233.3337324-7-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Use the host save area to save/restore non-volatile (callee-saved)
registers in __svm_sev_es_vcpu_run() to take advantage of hardware loading
all registers from the save area on #VMEXIT. KVM still needs to save the
registers it wants restored, but the loads are handled automatically by
hardware.
Aside from less assembly code, letting hardware do the restoration means
stack frames are preserved for the entirety of __svm_sev_es_vcpu_run().
Opportunistically add a comment to call out why @svm needs to be saved
across VMRUN->#VMEXIT, as it's not easy to decipher that from the macro
hell.
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Michael Roth <michael.roth@amd.com>
Cc: Alexey Kardashevskiy <aik@amd.com>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lore.kernel.org/r/20240223204233.3337324-6-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
POP @spec_ctrl_intercepted into RAX instead of RBX when discarding it from
the stack so that __svm_sev_es_vcpu_run() doesn't modify any non-volatile
registers. __svm_sev_es_vcpu_run() doesn't return a value, and RAX is
already are clobbered multiple times in the #VMEXIT path.
This will allowing using the host save area to save/restore non-volatile
registers in __svm_sev_es_vcpu_run().
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lore.kernel.org/r/20240223204233.3337324-5-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Drop 32-bit "support" from __svm_sev_es_vcpu_run(), as SEV/SEV-ES firmly
64-bit only. The "support" was purely the result of bad copy+paste from
__svm_vcpu_run(), which in turn was slightly less bad copy+paste from
__vmx_vcpu_run().
Opportunistically convert to unadulterated register accesses so that it's
easier (but still not easy) to follow which registers hold what arguments,
and when.
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lore.kernel.org/r/20240223204233.3337324-4-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Compile (and link) __svm_sev_es_vcpu_run() if and only if SEV support is
actually enabled. This will allow dropping non-existent 32-bit "support"
from __svm_sev_es_vcpu_run() without causing undue confusion.
Intentionally don't provide a stub (but keep the declaration), as any sane
compiler, even with things like KASAN enabled, should eliminate the call
to __svm_sev_es_vcpu_run() since sev_es_guest() unconditionally returns
"false" if CONFIG_KVM_AMD_SEV=n.
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lore.kernel.org/r/20240223204233.3337324-3-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Unconditionally create a stack frame in __svm_vcpu_run() to play nice with
unwinding via frame pointers, at least until the point where RBP is loaded
with the guest's value. Don't bother conditioning the code on
CONFIG_FRAME_POINTER=y, as RBP needs to be saved and restored anyways (due
to it being clobbered with the guest's value); omitting the "MOV RSP, RBP"
is not worth the extra #ifdef.
Creating a stack frame will allow removing the OBJECT_FILES_NON_STANDARD
tag from vmenter.S once __svm_sev_es_vcpu_run() is fixed to not stomp all
over RBP for no reason.
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lore.kernel.org/r/20240223204233.3337324-2-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Remove KVM's unnecessary zeroing of memory when allocating the pages array
in sev_pin_memory() via __vmalloc(), as the array is only used to hold
kernel pointers. The kmalloc() path for "small" regions doesn't zero the
array, and if KVM leaks state and/or accesses uninitialized data, then the
kernel has bigger problems.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/c7619a3d3cbb36463531a7c73ccbde9db587986c.1710004509.git.christophe.jaillet@wanadoo.fr
[sean: massage changelog]
Signed-off-by: Sean Christopherson <seanjc@google.com>
When zapping TDP MMU SPTEs under read-lock, processes zapped SPTEs *after*
flushing TLBs and after replacing the special REMOVED_SPTE with '0'.
When zapping an SPTE that points to a page table, processing SPTEs after
flushing TLBs minimizes contention on the child SPTEs (e.g. vCPUs won't
hit write-protection faults via stale, read-only child SPTEs), and
processing after replacing REMOVED_SPTE with '0' minimizes the amount of
time vCPUs will be blocked by the REMOVED_SPTE.
Processing SPTEs after setting the SPTE to '0', i.e. in parallel with the
SPTE potentially being replacing with a new SPTE, is safe because KVM does
not depend on completing the processing before a new SPTE is installed, and
the processing is done on a subset of the page tables that is disconnected
from the root, and thus unreachable by other tasks (after the TLB flush).
KVM already relies on similar logic, as kvm_mmu_zap_all_fast() can result
in KVM processing all SPTEs in a given root after vCPUs create mappings in
a new root.
In VMs with a large (400+) number of vCPUs, it can take KVM multiple
seconds to process a 1GiB region mapped with 4KiB entries, e.g. when
disabling dirty logging in a VM backed by 1GiB HugeTLB. During those
seconds, if a vCPU accesses the 1GiB region being zapped it will be
stalled until KVM finishes processing the SPTE and replaces the
REMOVED_SPTE with 0.
Re-ordering the processing does speed up the atomic-zaps somewhat, but
the main benefit is avoiding blocking vCPU threads.
Before:
$ ./dirty_log_perf_test -s anonymous_hugetlb_1gb -v 416 -b 1G -e
...
Disabling dirty logging time: 509.765146313s
$ ./funclatency -m tdp_mmu_zap_spte_atomic
msec : count distribution
0 -> 1 : 0 | |
2 -> 3 : 0 | |
4 -> 7 : 0 | |
8 -> 15 : 0 | |
16 -> 31 : 0 | |
32 -> 63 : 0 | |
64 -> 127 : 0 | |
128 -> 255 : 8 |** |
256 -> 511 : 68 |****************** |
512 -> 1023 : 129 |********************************** |
1024 -> 2047 : 151 |****************************************|
2048 -> 4095 : 60 |*************** |
After:
$ ./dirty_log_perf_test -s anonymous_hugetlb_1gb -v 416 -b 1G -e
...
Disabling dirty logging time: 336.516838548s
$ ./funclatency -m tdp_mmu_zap_spte_atomic
msec : count distribution
0 -> 1 : 0 | |
2 -> 3 : 0 | |
4 -> 7 : 0 | |
8 -> 15 : 0 | |
16 -> 31 : 0 | |
32 -> 63 : 0 | |
64 -> 127 : 0 | |
128 -> 255 : 12 |** |
256 -> 511 : 166 |****************************************|
512 -> 1023 : 101 |************************ |
1024 -> 2047 : 137 |********************************* |
Note, KVM's processing of collapsible SPTEs is still extremely slow and
can be improved. For example, a significant amount of time is spent
calling kvm_set_pfn_{accessed,dirty}() for every last-level SPTE, even
when processing SPTEs that all map the same folio. But avoiding blocking
vCPUs and contending SPTEs is valuable regardless of how fast KVM can
process collapsible SPTEs.
Link: https://lore.kernel.org/all/20240320005024.3216282-1-seanjc@google.com
Cc: Vipin Sharma <vipinsh@google.com>
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: David Matlack <dmatlack@google.com>
Reviewed-by: Vipin Sharma <vipinsh@google.com>
Link: https://lore.kernel.org/r/20240307194059.1357377-1-dmatlack@google.com
[sean: massage changelog]
Signed-off-by: Sean Christopherson <seanjc@google.com>
There's no need to carve out bits of the NOP optimization functionality
and look at JMP opcodes - simply do one more NOPs optimization pass
at the end of patching.
A lot simpler code.
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20240130105941.19707-3-bp@alien8.de
Instead of optimizing NOPs in-place, use a temporary buffer like the
usual alternatives patching flow does. This obviates the need to grab
locks when patching, see
6778977590 ("x86/alternatives: Disable interrupts and sync when optimizing NOPs in place")
While at it, add nomenclature definitions clarifying and simplifying the
naming of function-local variables in the alternatives code.
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20240130105941.19707-2-bp@alien8.de
After alternatives have been patched, changes to the X86_FEATURE flags
won't take effect and could potentially even be wrong.
Warn about it.
This is something which has been long overdue.
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Srikanth Aithal <sraithal@amd.com>
Link: https://lore.kernel.org/r/20240327154317.29909-3-bp@alien8.de
The code in thunk_64.S and thunk_32.S are exactly the same except for
the comments. Merge them in to thunk.S.
And since thunk_32.S was originated from thunk_64.S, the new merged
thunk.S is actually renamed from thunk_64.S.
Signed-off-by: Lai Jiangshan <jiangshan.ljs@antgroup.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20240407090558.3395-9-jiangshanlai@gmail.com
Machine check SMIs (MSMI) signaled during SEAM operation (typically
inside TDX guests), on a system with Intel eMCA enabled, might eventually
be reported to the kernel #MC handler with the saved RIP on the stack
pointing to the instruction in kernel code after the SEAMCALL instruction
that entered the SEAM operation. Linux currently says that is a fatal
error and shuts down.
There is a new bit in IA32_MCG_STATUS that, when set to 1, indicates
that the machine check didn't originally occur at that saved RIP, but
during SEAM non-root operation.
Add new entries to the severity table to detect this for both data load
and instruction fetch that set the severity to "AR" (action required).
Increase the width of the mcgmask/mcgres fields in "struct severity"
from unsigned char to unsigned short since the new bit is in position 12.
Action required for these errors is just mark the page as poisoned and
return from the machine check handler.
HW ABI notes:
=============
The SEAM_NR bit in IA32_MCG_STATUS hasn't yet made it into the Intel
Software Developers' Manual. But it is described in section 16.5.2
of "Intel(R) Trust Domain Extensions (Intel(R) TDX) Module Base
Architecture Specification" downloadable from:
https://cdrdv2.intel.com/v1/dl/getContent/733575
Backport notes:
===============
Little value in backporting this patch to stable or LTS kernels as
this is only relevant with support for TDX, which I assume won't be
backported. But for anyone taking this to v6.1 or older, you also
need commit:
a51cbd0d86 ("x86/mce: Use severity table to handle uncorrected errors in kernel")
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20240408180944.44638-1-tony.luck@intel.com
Branch History Injection (BHI) attacks may allow a malicious application to
influence indirect branch prediction in kernel by poisoning the branch
history. eIBRS isolates indirect branch targets in ring0. The BHB can
still influence the choice of indirect branch predictor entry, and although
branch predictor entries are isolated between modes when eIBRS is enabled,
the BHB itself is not isolated between modes.
Add mitigations against it either with the help of microcode or with
software sequences for the affected CPUs.
-----BEGIN PGP SIGNATURE-----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=W0W3
-----END PGP SIGNATURE-----
Merge tag 'nativebhi' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 mitigations from Thomas Gleixner:
"Mitigations for the native BHI hardware vulnerabilty:
Branch History Injection (BHI) attacks may allow a malicious
application to influence indirect branch prediction in kernel by
poisoning the branch history. eIBRS isolates indirect branch targets
in ring0. The BHB can still influence the choice of indirect branch
predictor entry, and although branch predictor entries are isolated
between modes when eIBRS is enabled, the BHB itself is not isolated
between modes.
Add mitigations against it either with the help of microcode or with
software sequences for the affected CPUs"
[ This also ends up enabling the full mitigation by default despite the
system call hardening, because apparently there are other indirect
calls that are still sufficiently reachable, and the 'auto' case just
isn't hardened enough.
We'll have some more inevitable tweaking in the future - Linus ]
* tag 'nativebhi' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
KVM: x86: Add BHI_NO
x86/bhi: Mitigate KVM by default
x86/bhi: Add BHI mitigation knob
x86/bhi: Enumerate Branch History Injection (BHI) bug
x86/bhi: Define SPEC_CTRL_BHI_DIS_S
x86/bhi: Add support for clearing branch history at syscall entry
x86/syscall: Don't force use of indirect calls for system calls
x86/bugs: Change commas to semicolons in 'spectre_v2' sysfs file
Use the raw/true host.MAXPHYADDR when deciding whether or not KVM must
intercept #PFs when allow_smaller_maxphyaddr is enabled, as any adjustments
the kernel makes to boot_cpu_data.x86_phys_bits to account for MKTME KeyID
bits do not apply to the guest physical address space. I.e. the KeyID are
off-limits for host physical addresses, but are not reserved for GPAs as
far as hardware is concerned.
Signed-off-by: Tao Su <tao1.su@linux.intel.com>
Link: https://lore.kernel.org/r/20240319031111.495006-1-tao1.su@linux.intel.com
[sean: massage changelog]
Signed-off-by: Sean Christopherson <seanjc@google.com>
Set the enable bits for general purpose counters in IA32_PERF_GLOBAL_CTRL
when refreshing the PMU to emulate the MSR's architecturally defined
post-RESET behavior. Per Intel's SDM:
IA32_PERF_GLOBAL_CTRL: Sets bits n-1:0 and clears the upper bits.
and
Where "n" is the number of general-purpose counters available in the processor.
AMD also documents this behavior for PerfMonV2 CPUs in one of AMD's many
PPRs.
Do not set any PERF_GLOBAL_CTRL bits if there are no general purpose
counters, although a literal reading of the SDM would require the CPU to
set either bits 63:0 or 31:0. The intent of the behavior is to globally
enable all GP counters; honor the intent, if not the letter of the law.
Leaving PERF_GLOBAL_CTRL '0' effectively breaks PMU usage in guests that
haven't been updated to work with PMUs that support PERF_GLOBAL_CTRL.
This bug was recently exposed when KVM added supported for AMD's
PerfMonV2, i.e. when KVM started exposing a vPMU with PERF_GLOBAL_CTRL to
guest software that only knew how to program v1 PMUs (that don't support
PERF_GLOBAL_CTRL).
Failure to emulate the post-RESET behavior results in such guests
unknowingly leaving all general purpose counters globally disabled (the
entire reason the post-RESET value sets the GP counter enable bits is to
maintain backwards compatibility).
The bug has likely gone unnoticed because PERF_GLOBAL_CTRL has been
supported on Intel CPUs for as long as KVM has existed, i.e. hardly anyone
is running guest software that isn't aware of PERF_GLOBAL_CTRL on Intel
PMUs. And because up until v6.0, KVM _did_ emulate the behavior for Intel
CPUs, although the old behavior was likely dumb luck.
Because (a) that old code was also broken in its own way (the history of
this code is a comedy of errors), and (b) PERF_GLOBAL_CTRL was documented
as having a value of '0' post-RESET in all SDMs before March 2023.
Initial vPMU support in commit f5132b0138 ("KVM: Expose a version 2
architectural PMU to a guests") *almost* got it right (again likely by
dumb luck), but for some reason only set the bits if the guest PMU was
advertised as v1:
if (pmu->version == 1) {
pmu->global_ctrl = (1 << pmu->nr_arch_gp_counters) - 1;
return;
}
Commit f19a0c2c2e ("KVM: PMU emulation: GLOBAL_CTRL MSR should be
enabled on reset") then tried to remedy that goof, presumably because
guest PMUs were leaving PERF_GLOBAL_CTRL '0', i.e. weren't enabling
counters.
pmu->global_ctrl = ((1 << pmu->nr_arch_gp_counters) - 1) |
(((1ull << pmu->nr_arch_fixed_counters) - 1) << X86_PMC_IDX_FIXED);
pmu->global_ctrl_mask = ~pmu->global_ctrl;
That was KVM's behavior up until commit c49467a45f ("KVM: x86/pmu:
Don't overwrite the pmu->global_ctrl when refreshing") removed
*everything*. However, it did so based on the behavior defined by the
SDM , which at the time stated that "Global Perf Counter Controls" is
'0' at Power-Up and RESET.
But then the March 2023 SDM (325462-079US), stealthily changed its
"IA-32 and Intel 64 Processor States Following Power-up, Reset, or INIT"
table to say:
IA32_PERF_GLOBAL_CTRL: Sets bits n-1:0 and clears the upper bits.
Note, kvm_pmu_refresh() can be invoked multiple times, i.e. it's not a
"pure" RESET flow. But it can only be called prior to the first KVM_RUN,
i.e. the guest will only ever observe the final value.
Note #2, KVM has always cleared global_ctrl during refresh (see commit
f5132b0138 ("KVM: Expose a version 2 architectural PMU to a guests")),
i.e. there is no danger of breaking existing setups by clobbering a value
set by userspace.
Reported-by: Babu Moger <babu.moger@amd.com>
Cc: Sandipan Das <sandipan.das@amd.com>
Cc: Like Xu <like.xu.linux@gmail.com>
Cc: Mingwei Zhang <mizhang@google.com>
Cc: Dapeng Mi <dapeng1.mi@linux.intel.com>
Cc: stable@vger.kernel.org
Reviewed-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
Tested-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
Link: https://lore.kernel.org/r/20240309013641.1413400-2-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Fix KVM_SET_MEMORY_ATTRIBUTES to not overflow lpage_info array and trigger
KASAN splat, as seen in the private_mem_conversions_test selftest.
When memory attributes are set on a GFN range, that range will have
specific properties applied to the TDP. A huge page cannot be used when
the attributes are inconsistent, so they are disabled for those the
specific huge pages. For internal KVM reasons, huge pages are also not
allowed to span adjacent memslots regardless of whether the backing memory
could be mapped as huge.
What GFNs support which huge page sizes is tracked by an array of arrays
'lpage_info' on the memslot, of ‘kvm_lpage_info’ structs. Each index of
lpage_info contains a vmalloc allocated array of these for a specific
supported page size. The kvm_lpage_info denotes whether a specific huge
page (GFN and page size) on the memslot is supported. These arrays include
indices for unaligned head and tail huge pages.
Preventing huge pages from spanning adjacent memslot is covered by
incrementing the count in head and tail kvm_lpage_info when the memslot is
allocated, but disallowing huge pages for memory that has mixed attributes
has to be done in a more complicated way. During the
KVM_SET_MEMORY_ATTRIBUTES ioctl KVM updates lpage_info for each memslot in
the range that has mismatched attributes. KVM does this a memslot at a
time, and marks a special bit, KVM_LPAGE_MIXED_FLAG, in the kvm_lpage_info
for any huge page. This bit is essentially a permanently elevated count.
So huge pages will not be mapped for the GFN at that page size if the
count is elevated in either case: a huge head or tail page unaligned to
the memslot or if KVM_LPAGE_MIXED_FLAG is set because it has mixed
attributes.
To determine whether a huge page has consistent attributes, the
KVM_SET_MEMORY_ATTRIBUTES operation checks an xarray to make sure it
consistently has the incoming attribute. Since level - 1 huge pages are
aligned to level huge pages, it employs an optimization. As long as the
level - 1 huge pages are checked first, it can just check these and assume
that if each level - 1 huge page contained within the level sized huge
page is not mixed, then the level size huge page is not mixed. This
optimization happens in the helper hugepage_has_attrs().
Unfortunately, although the kvm_lpage_info array representing page size
'level' will contain an entry for an unaligned tail page of size level,
the array for level - 1 will not contain an entry for each GFN at page
size level. The level - 1 array will only contain an index for any
unaligned region covered by level - 1 huge page size, which can be a
smaller region. So this causes the optimization to overflow the level - 1
kvm_lpage_info and perform a vmalloc out of bounds read.
In some cases of head and tail pages where an overflow could happen,
callers skip the operation completely as KVM_LPAGE_MIXED_FLAG is not
required to prevent huge pages as discussed earlier. But for memslots that
are smaller than the 1GB page size, it does call hugepage_has_attrs(). In
this case the huge page is both the head and tail page. The issue can be
observed simply by compiling the kernel with CONFIG_KASAN_VMALLOC and
running the selftest “private_mem_conversions_test”, which produces the
output like the following:
BUG: KASAN: vmalloc-out-of-bounds in hugepage_has_attrs+0x7e/0x110
Read of size 4 at addr ffffc900000a3008 by task private_mem_con/169
Call Trace:
dump_stack_lvl
print_report
? __virt_addr_valid
? hugepage_has_attrs
? hugepage_has_attrs
kasan_report
? hugepage_has_attrs
hugepage_has_attrs
kvm_arch_post_set_memory_attributes
kvm_vm_ioctl
It is a little ambiguous whether the unaligned head page (in the bug case
also the tail page) should be expected to have KVM_LPAGE_MIXED_FLAG set.
It is not functionally required, as the unaligned head/tail pages will
already have their kvm_lpage_info count incremented. The comments imply
not setting it on unaligned head pages is intentional, so fix the callers
to skip trying to set KVM_LPAGE_MIXED_FLAG in this case, and in doing so
not call hugepage_has_attrs().
Cc: stable@vger.kernel.org
Fixes: 90b4fe1798 ("KVM: x86: Disallow hugepages when memory attributes are mixed")
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Reviewed-by: Kai Huang <kai.huang@intel.com>
Reviewed-by: Chao Peng <chao.p.peng@linux.intel.com>
Link: https://lore.kernel.org/r/20240314212902.2762507-1-rick.p.edgecombe@intel.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Drop support for virtualizing adaptive PEBS, as KVM's implementation is
architecturally broken without an obvious/easy path forward, and because
exposing adaptive PEBS can leak host LBRs to the guest, i.e. can leak
host kernel addresses to the guest.
Bug #1 is that KVM doesn't account for the upper 32 bits of
IA32_FIXED_CTR_CTRL when (re)programming fixed counters, e.g
fixed_ctrl_field() drops the upper bits, reprogram_fixed_counters()
stores local variables as u8s and truncates the upper bits too, etc.
Bug #2 is that, because KVM _always_ sets precise_ip to a non-zero value
for PEBS events, perf will _always_ generate an adaptive record, even if
the guest requested a basic record. Note, KVM will also enable adaptive
PEBS in individual *counter*, even if adaptive PEBS isn't exposed to the
guest, but this is benign as MSR_PEBS_DATA_CFG is guaranteed to be zero,
i.e. the guest will only ever see Basic records.
Bug #3 is in perf. intel_pmu_disable_fixed() doesn't clear the upper
bits either, i.e. leaves ICL_FIXED_0_ADAPTIVE set, and
intel_pmu_enable_fixed() effectively doesn't clear ICL_FIXED_0_ADAPTIVE
either. I.e. perf _always_ enables ADAPTIVE counters, regardless of what
KVM requests.
Bug #4 is that adaptive PEBS *might* effectively bypass event filters set
by the host, as "Updated Memory Access Info Group" records information
that might be disallowed by userspace via KVM_SET_PMU_EVENT_FILTER.
Bug #5 is that KVM doesn't ensure LBR MSRs hold guest values (or at least
zeros) when entering a vCPU with adaptive PEBS, which allows the guest
to read host LBRs, i.e. host RIPs/addresses, by enabling "LBR Entries"
records.
Disable adaptive PEBS support as an immediate fix due to the severity of
the LBR leak in particular, and because fixing all of the bugs will be
non-trivial, e.g. not suitable for backporting to stable kernels.
Note! This will break live migration, but trying to make KVM play nice
with live migration would be quite complicated, wouldn't be guaranteed to
work (i.e. KVM might still kill/confuse the guest), and it's not clear
that there are any publicly available VMMs that support adaptive PEBS,
let alone live migrate VMs that support adaptive PEBS, e.g. QEMU doesn't
support PEBS in any capacity.
Link: https://lore.kernel.org/all/20240306230153.786365-1-seanjc@google.com
Link: https://lore.kernel.org/all/ZeepGjHCeSfadANM@google.com
Fixes: c59a1f106f ("KVM: x86/pmu: Add IA32_PEBS_ENABLE MSR emulation for extended PEBS")
Cc: stable@vger.kernel.org
Cc: Like Xu <like.xu.linux@gmail.com>
Cc: Mingwei Zhang <mizhang@google.com>
Cc: Zhenyu Wang <zhenyuw@linux.intel.com>
Cc: Zhang Xiong <xiong.y.zhang@intel.com>
Cc: Lv Zhiyuan <zhiyuan.lv@intel.com>
Cc: Dapeng Mi <dapeng1.mi@intel.com>
Cc: Jim Mattson <jmattson@google.com>
Acked-by: Like Xu <likexu@tencent.com>
Link: https://lore.kernel.org/r/20240307005833.827147-1-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Intel processors that aren't vulnerable to BHI will set
MSR_IA32_ARCH_CAPABILITIES[BHI_NO] = 1;. Guests may use this BHI_NO bit to
determine if they need to implement BHI mitigations or not. Allow this bit
to be passed to the guests.
Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.intel.com>
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Reviewed-by: Josh Poimboeuf <jpoimboe@kernel.org>
BHI mitigation mode spectre_bhi=auto does not deploy the software
mitigation by default. In a cloud environment, it is a likely scenario
where userspace is trusted but the guests are not trusted. Deploying
system wide mitigation in such cases is not desirable.
Update the auto mode to unconditionally mitigate against malicious
guests. Deploy the software sequence at VMexit in auto mode also, when
hardware mitigation is not available. Unlike the force =on mode,
software sequence is not deployed at syscalls in auto mode.
Suggested-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Reviewed-by: Josh Poimboeuf <jpoimboe@kernel.org>
Branch history clearing software sequences and hardware control
BHI_DIS_S were defined to mitigate Branch History Injection (BHI).
Add cmdline spectre_bhi={on|off|auto} to control BHI mitigation:
auto - Deploy the hardware mitigation BHI_DIS_S, if available.
on - Deploy the hardware mitigation BHI_DIS_S, if available,
otherwise deploy the software sequence at syscall entry and
VMexit.
off - Turn off BHI mitigation.
The default is auto mode which does not deploy the software sequence
mitigation. This is because of the hardening done in the syscall
dispatch path, which is the likely target of BHI.
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Reviewed-by: Josh Poimboeuf <jpoimboe@kernel.org>
Mitigation for BHI is selected based on the bug enumeration. Add bits
needed to enumerate BHI bug.
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Reviewed-by: Josh Poimboeuf <jpoimboe@kernel.org>
Newer processors supports a hardware control BHI_DIS_S to mitigate
Branch History Injection (BHI). Setting BHI_DIS_S protects the kernel
from userspace BHI attacks without having to manually overwrite the
branch history.
Define MSR_SPEC_CTRL bit BHI_DIS_S and its enumeration CPUID.BHI_CTRL.
Mitigation is enabled later.
Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.intel.com>
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Reviewed-by: Josh Poimboeuf <jpoimboe@kernel.org>
Branch History Injection (BHI) attacks may allow a malicious application to
influence indirect branch prediction in kernel by poisoning the branch
history. eIBRS isolates indirect branch targets in ring0. The BHB can
still influence the choice of indirect branch predictor entry, and although
branch predictor entries are isolated between modes when eIBRS is enabled,
the BHB itself is not isolated between modes.
Alder Lake and new processors supports a hardware control BHI_DIS_S to
mitigate BHI. For older processors Intel has released a software sequence
to clear the branch history on parts that don't support BHI_DIS_S. Add
support to execute the software sequence at syscall entry and VMexit to
overwrite the branch history.
For now, branch history is not cleared at interrupt entry, as malicious
applications are not believed to have sufficient control over the
registers, since previous register state is cleared at interrupt
entry. Researchers continue to poke at this area and it may become
necessary to clear at interrupt entry as well in the future.
This mitigation is only defined here. It is enabled later.
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Co-developed-by: Daniel Sneddon <daniel.sneddon@linux.intel.com>
Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Reviewed-by: Josh Poimboeuf <jpoimboe@kernel.org>
Make <asm/syscall.h> build a switch statement instead, and the compiler can
either decide to generate an indirect jump, or - more likely these days due
to mitigations - just a series of conditional branches.
Yes, the conditional branches also have branch prediction, but the branch
prediction is much more controlled, in that it just causes speculatively
running the wrong system call (harmless), rather than speculatively running
possibly wrong random less controlled code gadgets.
This doesn't mitigate other indirect calls, but the system call indirection
is the first and most easily triggered case.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Josh Poimboeuf <jpoimboe@kernel.org>
Change the format of the 'spectre_v2' vulnerabilities sysfs file
slightly by converting the commas to semicolons, so that mitigations for
future variants can be grouped together and separated by commas.
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
clang-16 warns about casting function pointers with incompatible
prototypes. The x86 math-emu code does this in a number of places
to call some trivial functions that need no arguments:
arch/x86/math-emu/fpu_etc.c:124:14: error: cast from 'void (*)(void)' to 'FUNC_ST0' \
(aka 'void (*)(struct fpu__reg *, unsigned char)') converts to incompatible function \
type [-Werror,-Wcast-function-type-strict]
124 | fchs, fabs, (FUNC_ST0) FPU_illegal, (FUNC_ST0) FPU_illegal,
| ^~~~~~~~~~~~~~~~~~~~~~
arch/x86/math-emu/fpu_trig.c:1634:19: error: cast from 'void (*)(void)' to 'FUNC_ST0' \
(aka 'void (*)(struct fpu__reg *, unsigned char)') converts to incompatible function \
type [-Werror,-Wcast-function-type-strict]
1634 | fxtract, fprem1, (FUNC_ST0) fdecstp, (FUNC_ST0) fincstp
| ^~~~~~~~~~~~~~~~~~
arch/x86/math-emu/reg_constant.c:112:53: error: cast from 'void (*)(void)' to 'FUNC_RC' \
(aka 'void (*)(int)') converts to incompatible function \
type [-Werror,-Wcast-function-type-strict]
112 | fld1, fldl2t, fldl2e, fldpi, fldlg2, fldln2, fldz, (FUNC_RC) FPU_illegal
Change the fdecstp() and fincstp() functions to actually have the correct
prototypes based on the caller, and add wrappers around FPU_illegal() for
adapting those.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/lkml/20240213095631.454543-1-arnd@kernel.org
When done from a virtual machine, instructions that touch APIC memory
must be emulated. By convention, MMIO accesses are typically performed
via io.h helpers such as readl() or writeq() to simplify instruction
emulation/decoding (ex: in KVM hosts and SEV guests) [0].
Currently, native_apic_mem_read() does not follow this convention,
allowing the compiler to emit instructions other than the MOV
instruction generated by readl(). In particular, when the kernel is
compiled with clang and run as a SEV-ES or SEV-SNP guest, the compiler
would emit a TESTL instruction which is not supported by the SEV-ES
emulator, causing a boot failure in that environment. It is likely the
same problem would happen in a TDX guest as that uses the same
instruction emulator as SEV-ES.
To make sure all emulators can emulate APIC memory reads via MOV, use
the readl() function in native_apic_mem_read(). It is expected that any
emulator would support MOV in any addressing mode as it is the most
generic and is what is usually emitted currently.
The TESTL instruction is emitted when native_apic_mem_read() is inlined
into apic_mem_wait_icr_idle(). The emulator comes from
insn_decode_mmio() in arch/x86/lib/insn-eval.c. It's not worth it to
extend insn_decode_mmio() to support more instructions since, in theory,
the compiler could choose to output nearly any instruction for such
reads which would bloat the emulator beyond reason.
[0] https://lore.kernel.org/all/20220405232939.73860-12-kirill.shutemov@linux.intel.com/
[ bp: Massage commit message, fix typos. ]
Signed-off-by: Adam Dunlap <acdunlap@google.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Tested-by: Kevin Loughlin <kevinloughlin@google.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20240318230927.2191933-1-acdunlap@google.com
Kernel timekeeping is designed to keep the change in cycles (since the last
timer interrupt) below max_cycles, which prevents multiplication overflow
when converting cycles to nanoseconds. However, if timer interrupts stop,
the calculation will eventually overflow.
Add protection against that. Select GENERIC_VDSO_OVERFLOW_PROTECT so that
max_cycles is made available in the VDSO data page. Check against
max_cycles, falling back to a slower higher precision calculation. Take
advantage of the opportunity to move masking and negative motion check
into the slow path.
The result is a calculation that has similar performance as before. Newer
machines showed performance benefit, whereas older Skylake-based hardware
such as Intel Kaby Lake was seen <1% worse.
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20240325064023.2997-9-adrian.hunter@intel.com
Consolidate nanoseconds calculation to simplify and reduce code
duplication.
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20240325064023.2997-3-adrian.hunter@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
-----BEGIN PGP SIGNATURE-----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=v7jY
-----END PGP SIGNATURE-----
Merge tag 'perf-urgent-2024-04-07' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 perf fix from Ingo Molnar:
"Fix a combined PEBS events bug on x86 Intel CPUs"
* tag 'perf-urgent-2024-04-07' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/x86/intel/ds: Don't clear ->pebs_data_cfg for the last PEBS event
srso_alias_untrain_ret() is special code, even if it is a dummy
which is called in the !SRSO case, so annotate it like its real
counterpart, to address the following objtool splat:
vmlinux.o: warning: objtool: .export_symbol+0x2b290: data relocation to !ENDBR: srso_alias_untrain_ret+0x0
Fixes: 4535e1a417 ("x86/bugs: Fix the SRSO mitigation on Zen3/4")
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20240405144637.17908-1-bp@kernel.org
We want to fix:
0e11073247 ("x86/retpoline: Do the necessary fixup to the Zen3/4 srso return thunk for !SRSO")
So merge in Linus's latest into x86/urgent to have it available.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Rewrite the whole family of x86_this_cpu_test_bit() functions
as macros, so standard __my_cpu_var() and raw_cpu_read() macros
can be used on percpu variables. This approach considerably
simplifies implementation of functions and also introduces
standard checks on accessed percpu variables.
No functional changes intended.
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20240404094218.448963-2-ubizjak@gmail.com
Fix x86_this_cpu_variable_test_bit(), which is implemented with an
incorrect asm template, where argument 2 (count argument) is considered
a percpu variable. However, x86_this_cpu_test_bit() is currently
used exclusively with constant bit number argument, so the called
x86_this_cpu_variable_test_bit() function is never instantiated.
The fix introduces named assembler operands to prevent this kind
of error.
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lore.kernel.org/r/20240404094218.448963-1-ubizjak@gmail.com
Older versions of clang show a warning for amd.c after a fix for a gcc
warning:
arch/x86/kernel/cpu/microcode/amd.c:478:47: error: format specifies type \
'unsigned char' but the argument has type 'u16' (aka 'unsigned short') [-Werror,-Wformat]
"amd-ucode/microcode_amd_fam%02hhxh.bin", family);
~~~~~~ ^~~~~~
%02hx
In clang-16 and higher, this warning is disabled by default, but clang-15 is
still supported, and it's trivial to avoid by adapting the types according
to the range of the passed data and the format string.
[ bp: Massage commit message. ]
Fixes: 2e9064facc ("x86/microcode/amd: Fix snprintf() format string warning in W=1 build")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20240405204919.1003409-1-arnd@kernel.org
There are a couple of fixups for this cycle's vmalloc changes and one for
the stackdepot changes. And a fix for a very old x86 PAT issue which can
cause a warning splat.
-----BEGIN PGP SIGNATURE-----
iHUEABYIAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCZhBEXAAKCRDdBJ7gKXxA
ju9fAQCxPdqApKQ49IAJpUtMcRJmI594dmB+/CfrFgiS+GaQcwEA1+2SidI9fQWT
R/fcKrRr4+zlgQw0T0aSDR1HBLUPxw0=
=rkxT
-----END PGP SIGNATURE-----
Merge tag 'mm-hotfixes-stable-2024-04-05-11-30' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull misc fixes from Andrew Morton:
"8 hotfixes, 3 are cc:stable
There are a couple of fixups for this cycle's vmalloc changes and one
for the stackdepot changes. And a fix for a very old x86 PAT issue
which can cause a warning splat"
* tag 'mm-hotfixes-stable-2024-04-05-11-30' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
stackdepot: rename pool_index to pool_index_plus_1
x86/mm/pat: fix VM_PAT handling in COW mappings
MAINTAINERS: change vmware.com addresses to broadcom.com
selftests/mm: include strings.h for ffsl
mm: vmalloc: fix lockdep warning
mm: vmalloc: bail out early in find_vmap_area() if vmap is not init
init: open output files from cpio unpacking with O_LARGEFILE
mm/secretmem: fix GUP-fast succeeding on secretmem folios
PAT handling won't do the right thing in COW mappings: the first PTE (or,
in fact, all PTEs) can be replaced during write faults to point at anon
folios. Reliably recovering the correct PFN and cachemode using
follow_phys() from PTEs will not work in COW mappings.
Using follow_phys(), we might just get the address+protection of the anon
folio (which is very wrong), or fail on swap/nonswap entries, failing
follow_phys() and triggering a WARN_ON_ONCE() in untrack_pfn() and
track_pfn_copy(), not properly calling free_pfn_range().
In free_pfn_range(), we either wouldn't call memtype_free() or would call
it with the wrong range, possibly leaking memory.
To fix that, let's update follow_phys() to refuse returning anon folios,
and fallback to using the stored PFN inside vma->vm_pgoff for COW mappings
if we run into that.
We will now properly handle untrack_pfn() with COW mappings, where we
don't need the cachemode. We'll have to fail fork()->track_pfn_copy() if
the first page was replaced by an anon folio, though: we'd have to store
the cachemode in the VMA to make this work, likely growing the VMA size.
For now, lets keep it simple and let track_pfn_copy() just fail in that
case: it would have failed in the past with swap/nonswap entries already,
and it would have done the wrong thing with anon folios.
Simple reproducer to trigger the WARN_ON_ONCE() in untrack_pfn():
<--- C reproducer --->
#include <stdio.h>
#include <sys/mman.h>
#include <unistd.h>
#include <liburing.h>
int main(void)
{
struct io_uring_params p = {};
int ring_fd;
size_t size;
char *map;
ring_fd = io_uring_setup(1, &p);
if (ring_fd < 0) {
perror("io_uring_setup");
return 1;
}
size = p.sq_off.array + p.sq_entries * sizeof(unsigned);
/* Map the submission queue ring MAP_PRIVATE */
map = mmap(0, size, PROT_READ | PROT_WRITE, MAP_PRIVATE,
ring_fd, IORING_OFF_SQ_RING);
if (map == MAP_FAILED) {
perror("mmap");
return 1;
}
/* We have at least one page. Let's COW it. */
*map = 0;
pause();
return 0;
}
<--- C reproducer --->
On a system with 16 GiB RAM and swap configured:
# ./iouring &
# memhog 16G
# killall iouring
[ 301.552930] ------------[ cut here ]------------
[ 301.553285] WARNING: CPU: 7 PID: 1402 at arch/x86/mm/pat/memtype.c:1060 untrack_pfn+0xf4/0x100
[ 301.553989] Modules linked in: binfmt_misc nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_g
[ 301.558232] CPU: 7 PID: 1402 Comm: iouring Not tainted 6.7.5-100.fc38.x86_64 #1
[ 301.558772] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebu4
[ 301.559569] RIP: 0010:untrack_pfn+0xf4/0x100
[ 301.559893] Code: 75 c4 eb cf 48 8b 43 10 8b a8 e8 00 00 00 3b 6b 28 74 b8 48 8b 7b 30 e8 ea 1a f7 000
[ 301.561189] RSP: 0018:ffffba2c0377fab8 EFLAGS: 00010282
[ 301.561590] RAX: 00000000ffffffea RBX: ffff9208c8ce9cc0 RCX: 000000010455e047
[ 301.562105] RDX: 07fffffff0eb1e0a RSI: 0000000000000000 RDI: ffff9208c391d200
[ 301.562628] RBP: 0000000000000000 R08: ffffba2c0377fab8 R09: 0000000000000000
[ 301.563145] R10: ffff9208d2292d50 R11: 0000000000000002 R12: 00007fea890e0000
[ 301.563669] R13: 0000000000000000 R14: ffffba2c0377fc08 R15: 0000000000000000
[ 301.564186] FS: 0000000000000000(0000) GS:ffff920c2fbc0000(0000) knlGS:0000000000000000
[ 301.564773] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 301.565197] CR2: 00007fea88ee8a20 CR3: 00000001033a8000 CR4: 0000000000750ef0
[ 301.565725] PKRU: 55555554
[ 301.565944] Call Trace:
[ 301.566148] <TASK>
[ 301.566325] ? untrack_pfn+0xf4/0x100
[ 301.566618] ? __warn+0x81/0x130
[ 301.566876] ? untrack_pfn+0xf4/0x100
[ 301.567163] ? report_bug+0x171/0x1a0
[ 301.567466] ? handle_bug+0x3c/0x80
[ 301.567743] ? exc_invalid_op+0x17/0x70
[ 301.568038] ? asm_exc_invalid_op+0x1a/0x20
[ 301.568363] ? untrack_pfn+0xf4/0x100
[ 301.568660] ? untrack_pfn+0x65/0x100
[ 301.568947] unmap_single_vma+0xa6/0xe0
[ 301.569247] unmap_vmas+0xb5/0x190
[ 301.569532] exit_mmap+0xec/0x340
[ 301.569801] __mmput+0x3e/0x130
[ 301.570051] do_exit+0x305/0xaf0
...
Link: https://lkml.kernel.org/r/20240403212131.929421-3-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reported-by: Wupeng Ma <mawupeng1@huawei.com>
Closes: https://lkml.kernel.org/r/20240227122814.3781907-1-mawupeng1@huawei.com
Fixes: b1a86e15dc ("x86, pat: remove the dependency on 'vm_pgoff' in track/untrack pfn vma routines")
Fixes: 5899329b19 ("x86: PAT: implement track/untrack of pfnmap regions for x86 - v3")
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Add an AES-XTS implementation "xts-aes-vaes-avx10_512" for x86_64 CPUs
with the VAES, VPCLMULQDQ, and either AVX10/512 or AVX512BW + AVX512VL
extensions. This implementation uses zmm registers to operate on four
AES blocks at a time. The assembly code is instantiated using a macro
so that most of the source code is shared with other implementations.
To avoid downclocking on older Intel CPU models, an exclusion list is
used to prevent this 512-bit implementation from being used by default
on some CPU models. They will use xts-aes-vaes-avx10_256 instead. For
now, this exclusion list is simply coded into aesni-intel_glue.c. It
may make sense to eventually move it into a more central location.
xts-aes-vaes-avx10_512 is slightly faster than xts-aes-vaes-avx10_256 on
some current CPUs. E.g., on AMD Zen 4, AES-256-XTS decryption
throughput increases by 13% with 4096-byte inputs, or 14% with 512-byte
inputs. On Intel Sapphire Rapids, AES-256-XTS decryption throughput
increases by 2% with 4096-byte inputs, or 3% with 512-byte inputs.
Future CPUs may provide stronger 512-bit support, in which case a larger
benefit should be seen.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Add an AES-XTS implementation "xts-aes-vaes-avx10_256" for x86_64 CPUs
with the VAES, VPCLMULQDQ, and either AVX10/256 or AVX512BW + AVX512VL
extensions. This implementation avoids using zmm registers, instead
using ymm registers to operate on two AES blocks at a time. The
assembly code is instantiated using a macro so that most of the source
code is shared with other implementations.
This is the optimal implementation on CPUs that support VAES and AVX512
but where the zmm registers should not be used due to downclocking
effects, for example Intel's Ice Lake. It should also be the optimal
implementation on future CPUs that support AVX10/256 but not AVX10/512.
The performance is slightly better than that of xts-aes-vaes-avx2, which
uses the same 256-bit vector length, due to factors such as being able
to use ymm16-ymm31 to cache the AES round keys, and being able to use
the vpternlogd instruction to do XORs more efficiently. For example, on
Ice Lake, the throughput of decrypting 4096-byte messages with
AES-256-XTS is 6.6% higher with xts-aes-vaes-avx10_256 than with
xts-aes-vaes-avx2. While this is a small improvement, it is
straightforward to provide this implementation (xts-aes-vaes-avx10_256)
as long as we are providing xts-aes-vaes-avx2 and xts-aes-vaes-avx10_512
anyway, due to the way the _aes_xts_crypt macro is structured.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Add an AES-XTS implementation "xts-aes-vaes-avx2" for x86_64 CPUs with
the VAES, VPCLMULQDQ, and AVX2 extensions, but not AVX512 or AVX10.
This implementation uses ymm registers to operate on two AES blocks at a
time. The assembly code is instantiated using a macro so that most of
the source code is shared with other implementations.
This is the optimal implementation on AMD Zen 3. It should also be the
optimal implementation on Intel Alder Lake, which similarly supports
VAES but not AVX512. Comparing to xts-aes-aesni-avx on Zen 3,
xts-aes-vaes-avx2 provides 70% higher AES-256-XTS decryption throughput
with 4096-byte messages, or 23% higher with 512-byte messages.
A large improvement is also seen with CPUs that do support AVX512 (e.g.,
98% higher AES-256-XTS decryption throughput on Ice Lake with 4096-byte
messages), though the following patches add AVX512 optimized
implementations to get a bit more performance on those CPUs.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Add an AES-XTS implementation "xts-aes-aesni-avx" for x86_64 CPUs that
have the AES-NI and AVX extensions but not VAES. It's similar to the
existing xts-aes-aesni in that uses xmm registers to operate on one AES
block at a time. It differs from xts-aes-aesni in the following ways:
- It uses the VEX-coded (non-destructive) instructions from AVX.
This improves performance slightly.
- It incorporates some additional optimizations such as interleaving the
tweak computation with AES en/decryption, handling single-page
messages more efficiently, and caching the first round key.
- It supports only 64-bit (x86_64).
- It's generated by an assembly macro that will also be used to generate
VAES-based implementations.
The performance improvement over xts-aes-aesni varies from small to
large, depending on the CPU and other factors such as the size of the
messages en/decrypted. For example, the following increases in
AES-256-XTS decryption throughput are seen on the following CPUs:
| 4096-byte messages | 512-byte messages |
----------------------+--------------------+-------------------+
Intel Skylake | 6% | 31% |
Intel Cascade Lake | 4% | 26% |
AMD Zen 1 | 61% | 73% |
AMD Zen 2 | 36% | 59% |
(The above CPUs don't support VAES, so they can't use VAES instead.)
While this isn't as large an improvement as what VAES provides, this
still seems worthwhile. This implementation is fairly easy to provide
based on the assembly macro that's needed for VAES anyway, and it will
be the best implementation on a large number of CPUs (very roughly, the
CPUs launched by Intel and AMD from 2011 to 2018).
This makes the existing xts-aes-aesni *mostly* obsolete. For now, leave
it in place to support 32-bit kernels and also CPUs like Intel Westmere
that support AES-NI but not AVX. (We could potentially remove it anyway
and just rely on the indirect acceleration via ecb-aes-aesni in those
cases, but that change will need to be considered separately.)
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Add an assembly file aes-xts-avx-x86_64.S which contains a macro that
expands into AES-XTS implementations for x86_64 CPUs that support at
least AES-NI and AVX, optionally also taking advantage of VAES,
VPCLMULQDQ, and AVX512 or AVX10.
This patch doesn't expand the macro at all. Later patches will do so,
adding each implementation individually so that the motivation and use
case for each individual implementation can be fully presented.
The file also provides a function aes_xts_encrypt_iv() which handles the
encryption of the IV (tweak), using AES-NI and AVX.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Add config symbols AS_VAES and AS_VPCLMULQDQ that expose whether the
assembler supports the vector AES and carryless multiplication
cryptographic extensions.
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Add CPUID_LNX_5 to track cpufeatures' word 21, and add the appropriate
compile-time assert in KVM to prevent direct lookups on the features in
CPUID_LNX_5. KVM uses X86_FEATURE_* flags to manage guest CPUID, and so
must translate features that are scattered by Linux from the Linux-defined
bit to the hardware-defined bit, i.e. should never try to directly access
scattered features in guest CPUID.
Opportunistically add NR_CPUID_WORDS to enum cpuid_leafs, along with a
compile-time assert in KVM's CPUID infrastructure to ensure that future
additions update cpuid_leafs along with NCAPINTS.
No functional change intended.
Fixes: 7f274e609f ("x86/cpufeatures: Add new word for scattered features")
Cc: Sandipan Das <sandipan.das@amd.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fairly usual collection of driver and core fixes. The large selftest
accompanying one of the fixes is also becoming a common occurrence.
Current release - regressions:
- ipv6: fix infinite recursion in fib6_dump_done()
- net/rds: fix possible null-deref in newly added error path
Current release - new code bugs:
- net: do not consume a full cacheline for system_page_pool
- bpf: fix bpf_arena-related file descriptor leaks in the verifier
- drv: ice: fix freeing uninitialized pointers, fixing misuse of
the newfangled __free() auto-cleanup
Previous releases - regressions:
- x86/bpf: fixes the BPF JIT with retbleed=stuff
- xen-netfront: add missing skb_mark_for_recycle, fix page pool
accounting leaks, revealed by recently added explicit warning
- tcp: fix bind() regression for v6-only wildcard and v4-mapped-v6
non-wildcard addresses
- Bluetooth:
- replace "hci_qca: Set BDA quirk bit if fwnode exists in DT"
with better workarounds to un-break some buggy Qualcomm devices
- set conn encrypted before conn establishes, fix re-connecting
to some headsets which use slightly unusual sequence of msgs
- mptcp:
- prevent BPF accessing lowat from a subflow socket
- don't account accept() of non-MPC client as fallback to TCP
- drv: mana: fix Rx DMA datasize and skb_over_panic
- drv: i40e: fix VF MAC filter removal
Previous releases - always broken:
- gro: various fixes related to UDP tunnels - netns crossing problems,
incorrect checksum conversions, and incorrect packet transformations
which may lead to panics
- bpf: support deferring bpf_link dealloc to after RCU grace period
- nf_tables:
- release batch on table validation from abort path
- release mutex after nft_gc_seq_end from abort path
- flush pending destroy work before exit_net release
- drv: r8169: skip DASH fw status checks when DASH is disabled
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
-----BEGIN PGP SIGNATURE-----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=6bQI
-----END PGP SIGNATURE-----
Merge tag 'net-6.9-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from Jakub Kicinski:
"Including fixes from netfilter, bluetooth and bpf.
Fairly usual collection of driver and core fixes. The large selftest
accompanying one of the fixes is also becoming a common occurrence.
Current release - regressions:
- ipv6: fix infinite recursion in fib6_dump_done()
- net/rds: fix possible null-deref in newly added error path
Current release - new code bugs:
- net: do not consume a full cacheline for system_page_pool
- bpf: fix bpf_arena-related file descriptor leaks in the verifier
- drv: ice: fix freeing uninitialized pointers, fixing misuse of the
newfangled __free() auto-cleanup
Previous releases - regressions:
- x86/bpf: fixes the BPF JIT with retbleed=stuff
- xen-netfront: add missing skb_mark_for_recycle, fix page pool
accounting leaks, revealed by recently added explicit warning
- tcp: fix bind() regression for v6-only wildcard and v4-mapped-v6
non-wildcard addresses
- Bluetooth:
- replace "hci_qca: Set BDA quirk bit if fwnode exists in DT" with
better workarounds to un-break some buggy Qualcomm devices
- set conn encrypted before conn establishes, fix re-connecting to
some headsets which use slightly unusual sequence of msgs
- mptcp:
- prevent BPF accessing lowat from a subflow socket
- don't account accept() of non-MPC client as fallback to TCP
- drv: mana: fix Rx DMA datasize and skb_over_panic
- drv: i40e: fix VF MAC filter removal
Previous releases - always broken:
- gro: various fixes related to UDP tunnels - netns crossing
problems, incorrect checksum conversions, and incorrect packet
transformations which may lead to panics
- bpf: support deferring bpf_link dealloc to after RCU grace period
- nf_tables:
- release batch on table validation from abort path
- release mutex after nft_gc_seq_end from abort path
- flush pending destroy work before exit_net release
- drv: r8169: skip DASH fw status checks when DASH is disabled"
* tag 'net-6.9-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (81 commits)
netfilter: validate user input for expected length
net/sched: act_skbmod: prevent kernel-infoleak
net: usb: ax88179_178a: avoid the interface always configured as random address
net: dsa: sja1105: Fix parameters order in sja1110_pcs_mdio_write_c45()
net: ravb: Always update error counters
net: ravb: Always process TX descriptor ring
netfilter: nf_tables: discard table flag update with pending basechain deletion
netfilter: nf_tables: Fix potential data-race in __nft_flowtable_type_get()
netfilter: nf_tables: reject new basechain after table flag update
netfilter: nf_tables: flush pending destroy work before exit_net release
netfilter: nf_tables: release mutex after nft_gc_seq_end from abort path
netfilter: nf_tables: release batch on table validation from abort path
Revert "tg3: Remove residual error handling in tg3_suspend"
tg3: Remove residual error handling in tg3_suspend
net: mana: Fix Rx DMA datasize and skb_over_panic
net/sched: fix lockdep splat in qdisc_tree_reduce_backlog()
net: phy: micrel: lan8814: Fix when enabling/disabling 1-step timestamping
net: stmmac: fix rx queue priority assignment
net: txgbe: fix i2c dev name cannot match clkdev
net: fec: Set mac_managed_pm during probe
...
Modifying a MCA bank's MCA_CTL bits which control which error types to
be reported is done over
/sys/devices/system/machinecheck/
├── machinecheck0
│ ├── bank0
│ ├── bank1
│ ├── bank10
│ ├── bank11
...
sysfs nodes by writing the new bit mask of events to enable.
When the write is accepted, the kernel deletes all current timers and
reinits all banks.
Doing that in parallel can lead to initializing a timer which is already
armed and in the timer wheel, i.e., in use already:
ODEBUG: init active (active state 0) object: ffff888063a28000 object
type: timer_list hint: mce_timer_fn+0x0/0x240 arch/x86/kernel/cpu/mce/core.c:2642
WARNING: CPU: 0 PID: 8120 at lib/debugobjects.c:514
debug_print_object+0x1a0/0x2a0 lib/debugobjects.c:514
Fix that by grabbing the sysfs mutex as the rest of the MCA sysfs code
does.
Reported by: Yue Sun <samsun1006219@gmail.com>
Reported by: xingwei lee <xrivendell7@gmail.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Cc: <stable@kernel.org>
Link: https://lore.kernel.org/r/CAEkJfYNiENwQY8yV1LYJ9LjJs%2Bx_-PqMv98gKig55=2vbzffRw@mail.gmail.com
After
034ff37d34 ("x86: rewrite '__copy_user_nocache' function")
rewrote __copy_user_nocache() to use EX_TYPE_UACCESS instead of the
EX_TYPE_COPY exception type, there are no more EX_TYPE_COPY users, so
remove it.
[ bp: Massage commit message. ]
Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20240204082627.3892816-2-tongtiangen@huawei.com
The host SNP worthiness can determined later, after alternatives have
been patched, in snp_rmptable_init() depending on cmdline options like
iommu=pt which is incompatible with SNP, for example.
Which means that one cannot use X86_FEATURE_SEV_SNP and will need to
have a special flag for that control.
Use that newly added CC_ATTR_HOST_SEV_SNP in the appropriate places.
Move kdump_sev_callback() to its rightful place, while at it.
Fixes: 216d106c7f ("x86/sev: Add SEV-SNP host initialization support")
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Tested-by: Srikanth Aithal <sraithal@amd.com>
Link: https://lore.kernel.org/r/20240327154317.29909-6-bp@alien8.de
Add functionality to set and/or clear different attributes of the
machine as a confidential computing platform. Add the first one too:
whether the machine is running as a host for SEV-SNP guests.
Fixes: 216d106c7f ("x86/sev: Add SEV-SNP host initialization support")
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Tested-by: Srikanth Aithal <sraithal@amd.com>
Link: https://lore.kernel.org/r/20240327154317.29909-5-bp@alien8.de
The functionality to load SEV-SNP guests by the host will soon rely on
cc_platform* helpers because the cpu_feature* API with the early
patching is insufficient when SNP support needs to be disabled late.
Therefore, pull that functionality in.
Fixes: 216d106c7f ("x86/sev: Add SEV-SNP host initialization support")
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Tested-by: Srikanth Aithal <sraithal@amd.com>
Link: https://lore.kernel.org/r/20240327154317.29909-4-bp@alien8.de
There are few uses of CoCo that don't rely on working cryptography and
hence a working RNG. Unfortunately, the CoCo threat model means that the
VM host cannot be trusted and may actively work against guests to
extract secrets or manipulate computation. Since a malicious host can
modify or observe nearly all inputs to guests, the only remaining source
of entropy for CoCo guests is RDRAND.
If RDRAND is broken -- due to CPU hardware fault -- the RNG as a whole
is meant to gracefully continue on gathering entropy from other sources,
but since there aren't other sources on CoCo, this is catastrophic.
This is mostly a concern at boot time when initially seeding the RNG, as
after that the consequences of a broken RDRAND are much more
theoretical.
So, try at boot to seed the RNG using 256 bits of RDRAND output. If this
fails, panic(). This will also trigger if the system is booted without
RDRAND, as RDRAND is essential for a safe CoCo boot.
Add this deliberately to be "just a CoCo x86 driver feature" and not
part of the RNG itself. Many device drivers and platforms have some
desire to contribute something to the RNG, and add_device_randomness()
is specifically meant for this purpose.
Any driver can call it with seed data of any quality, or even garbage
quality, and it can only possibly make the quality of the RNG better or
have no effect, but can never make it worse.
Rather than trying to build something into the core of the RNG, consider
the particular CoCo issue just a CoCo issue, and therefore separate it
all out into driver (well, arch/platform) code.
[ bp: Massage commit message. ]
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Elena Reshetova <elena.reshetova@intel.com>
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240326160735.73531-1-Jason@zx2c4.com
The following commit:
d69c1382e1 ("x86/kvm: Convert FPU handling to a single swap buffer")
reworked KVM FPU handling, but forgot to update the comments
in xstate_op_valid(): fpu_swap_kvm_fpu() doesn't exist anymore,
fpu_swap_kvm_fpstate() is used instead.
Update the comments accordingly.
[ mingo: Improved the changelog. ]
Signed-off-by: Li RongQing <lirongqing@baidu.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20240403091803.818-1-lirongqing@baidu.com
The __vmalloc_start_set declaration is in a header that is not included
in numa_32.c in current linux-next:
arch/x86/mm/numa_32.c: In function 'initmem_init':
arch/x86/mm/numa_32.c:57:9: error: '__vmalloc_start_set' undeclared (first use in this function)
57 | __vmalloc_start_set = true;
| ^~~~~~~~~~~~~~~~~~~
arch/x86/mm/numa_32.c:57:9: note: each undeclared identifier is reported only once for each function it appears in
Add an explicit #include.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20240403202344.3463169-1-arnd@kernel.org
Add a new BPF instruction for resolving absolute addresses of per-CPU
data from their per-CPU offsets. This instruction is internal-only and
users are not allowed to use them directly. They will only be used for
internal inlining optimizations for now between BPF verifier and BPF JITs.
We use a special BPF_MOV | BPF_ALU64 | BPF_X form with insn->off field
set to BPF_ADDR_PERCPU = -1. I used negative offset value to distinguish
them from positive ones used by user-exposed instructions.
Such instruction performs a resolution of a per-CPU offset stored in
a register to a valid kernel address which can be dereferenced. It is
useful in any use case where absolute address of a per-CPU data has to
be resolved (e.g., in inlining bpf_map_lookup_elem()).
BPF disassembler is also taught to recognize them to support dumping
final BPF assembly code (non-JIT'ed version).
Add arch-specific way for BPF JITs to mark support for this instructions.
This patch also adds support for these instructions in x86-64 BPF JIT.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/r/20240402021307.1012571-2-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
- Ensure perf events programmed to count during guest execution
are actually enabled before entering the guest in the nVHE
configuration.
- Restore out-of-range handler for stage-2 translation faults.
- Several fixes to stage-2 TLB invalidations to avoid stale
translations, possibly including partial walk caches.
- Fix early handling of architectural VHE-only systems to ensure E2H is
appropriately set.
- Correct a format specifier warning in the arch_timer selftest.
- Make the KVM banner message correctly handle all of the possible
configurations.
RISC-V:
- Remove redundant semicolon in num_isa_ext_regs().
- Fix APLIC setipnum_le/be write emulation.
- Fix APLIC in_clrip[x] read emulation.
x86:
- Fix a bug in KVM_SET_CPUID{2,} where KVM looks at the wrong CPUID entries (old
vs. new) and ultimately neglects to clear PV_UNHALT from vCPUs with HLT-exiting
disabled.
- Documentation fixes for SEV.
- Fix compat ABI for KVM_MEMORY_ENCRYPT_OP.
- Fix a 14-year-old goof in a declaration shared by host and guest; the enabled
field used by Linux when running as a guest pushes the size of "struct
kvm_vcpu_pv_apf_data" from 64 to 68 bytes. This is really unconsequential
because KVM never consumes anything beyond the first 64 bytes, but the
resulting struct does not match the documentation.
Selftests:
- Fix spelling mistake in arch_timer selftest.
-----BEGIN PGP SIGNATURE-----
iQFIBAABCAAyFiEE8TM4V0tmI4mGbHaCv/vSX3jHroMFAmYMOJYUHHBib256aW5p
QHJlZGhhdC5jb20ACgkQv/vSX3jHroP2zAf/Z7/cK0+yFSvm7/tsbWtjnWofad/p
82puu0V+8lZSjGVs3AydiDCV+FahvLS0QIwgrffVr4XA10Km5ZZMjZyJ3uH4xki/
VFFsDnZPdKuj55T0wwN7JFn0YVOMdtgcP0b+F8aMbkL0uoJXjutOMKNhssuW12kw
9cmPjaBWm/bfrfoTUUB9mCh0Ub3HKpguYwTLQuf6Fyn2FK7oORpt87Zi+oIKUn6H
pFXFtZYduLg6M2LXvZqsXZLXnvABPjANNWEhiiwrvuF/wmXXTwTpvRXlYXhCvpAN
q0AhxPhPm3NnsmRhEB6SmoMjXyZIByezcEiqAspBrUvEqs/2u6VyzFMrXw==
=PlsI
-----END PGP SIGNATURE-----
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM fixes from Paolo Bonzini:
"ARM:
- Ensure perf events programmed to count during guest execution are
actually enabled before entering the guest in the nVHE
configuration
- Restore out-of-range handler for stage-2 translation faults
- Several fixes to stage-2 TLB invalidations to avoid stale
translations, possibly including partial walk caches
- Fix early handling of architectural VHE-only systems to ensure E2H
is appropriately set
- Correct a format specifier warning in the arch_timer selftest
- Make the KVM banner message correctly handle all of the possible
configurations
RISC-V:
- Remove redundant semicolon in num_isa_ext_regs()
- Fix APLIC setipnum_le/be write emulation
- Fix APLIC in_clrip[x] read emulation
x86:
- Fix a bug in KVM_SET_CPUID{2,} where KVM looks at the wrong CPUID
entries (old vs. new) and ultimately neglects to clear PV_UNHALT
from vCPUs with HLT-exiting disabled
- Documentation fixes for SEV
- Fix compat ABI for KVM_MEMORY_ENCRYPT_OP
- Fix a 14-year-old goof in a declaration shared by host and guest;
the enabled field used by Linux when running as a guest pushes the
size of "struct kvm_vcpu_pv_apf_data" from 64 to 68 bytes. This is
really unconsequential because KVM never consumes anything beyond
the first 64 bytes, but the resulting struct does not match the
documentation
Selftests:
- Fix spelling mistake in arch_timer selftest"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (25 commits)
KVM: arm64: Rationalise KVM banner output
arm64: Fix early handling of FEAT_E2H0 not being implemented
KVM: arm64: Ensure target address is granule-aligned for range TLBI
KVM: arm64: Use TLBI_TTL_UNKNOWN in __kvm_tlb_flush_vmid_range()
KVM: arm64: Don't pass a TLBI level hint when zapping table entries
KVM: arm64: Don't defer TLB invalidation when zapping table entries
KVM: selftests: Fix __GUEST_ASSERT() format warnings in ARM's arch timer test
KVM: arm64: Fix out-of-IPA space translation fault handling
KVM: arm64: Fix host-programmed guest events in nVHE
RISC-V: KVM: Fix APLIC in_clrip[x] read emulation
RISC-V: KVM: Fix APLIC setipnum_le/be write emulation
RISC-V: KVM: Remove second semicolon
KVM: selftests: Fix spelling mistake "trigged" -> "triggered"
Documentation: kvm/sev: clarify usage of KVM_MEMORY_ENCRYPT_OP
Documentation: kvm/sev: separate description of firmware
KVM: SEV: fix compat ABI for KVM_MEMORY_ENCRYPT_OP
KVM: selftests: Check that PV_UNHALT is cleared when HLT exiting is disabled
KVM: x86: Use actual kvm_cpuid.base for clearing KVM_FEATURE_PV_UNHALT
KVM: x86: Introduce __kvm_get_hypervisor_cpuid() helper
KVM: SVM: Return -EINVAL instead of -EBUSY on attempt to re-init SEV/SEV-ES
...
The srso_alias_untrain_ret() dummy thunk in the !CONFIG_MITIGATION_SRSO
case is there only for the altenative in CALL_UNTRAIN_RET to have
a symbol to resolve.
However, testing with kernels which don't have CONFIG_MITIGATION_SRSO
enabled, leads to the warning in patch_return() to fire:
missing return thunk: srso_alias_untrain_ret+0x0/0x10-0x0: eb 0e 66 66 2e
WARNING: CPU: 0 PID: 0 at arch/x86/kernel/alternative.c:826 apply_returns (arch/x86/kernel/alternative.c:826
Put in a plain "ret" there so that gcc doesn't put a return thunk in
in its place which special and gets checked.
In addition:
ERROR: modpost: "srso_alias_untrain_ret" [arch/x86/kvm/kvm-amd.ko] undefined!
make[2]: *** [scripts/Makefile.modpost:145: Module.symvers] Chyba 1
make[1]: *** [/usr/src/linux-6.8.3/Makefile:1873: modpost] Chyba 2
make: *** [Makefile:240: __sub-make] Chyba 2
since !SRSO builds would use the dummy return thunk as reported by
petr.pisar@atlas.cz, https://bugzilla.kernel.org/show_bug.cgi?id=218679.
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202404020901.da75a60f-oliver.sang@intel.com
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/all/202404020901.da75a60f-oliver.sang@intel.com/
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Given that acpi_pm_read_early() returns a u32 (masked to 24 bits), several
variables that store its return value are improved by adjusting their data
types from unsigned long to u32. Specifically, change deltapm's type from
long to u32 because its value fits into 32 bits and it cannot be negative.
These data type improvements resolve the following two Coccinelle/
coccicheck warnings reported by do_div.cocci:
arch/x86/kernel/apic/apic.c:734:1-7: WARNING: do_div() does a 64-by-32
division, please consider using div64_long instead.
arch/x86/kernel/apic/apic.c:742:2-8: WARNING: do_div() does a 64-by-32
division, please consider using div64_long instead.
Signed-off-by: Thorsten Blum <thorsten.blum@toblux.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lore.kernel.org/all/20240318104721.117741-3-thorsten.blum%40toblux.com
The MSR_PEBS_DATA_CFG MSR register is used to configure which data groups
should be generated into a PEBS record, and it's shared among all counters.
If there are different configurations among counters, perf combines all the
configurations.
The first perf command as below requires a complete PEBS record
(including memory info, GPRs, XMMs, and LBRs). The second perf command
only requires a basic group. However, after the second perf command is
running, the MSR_PEBS_DATA_CFG register is cleared. Only a basic group is
generated in a PEBS record, which is wrong. The required information
for the first perf command is missed.
$ perf record --intr-regs=AX,SP,XMM0 -a -C 8 -b -W -d -c 100000003 -o /dev/null -e cpu/event=0xd0,umask=0x81/upp &
$ sleep 5
$ perf record --per-thread -c 1 -e cycles:pp --no-timestamp --no-tid taskset -c 8 ./noploop 1000
The first PEBS event is a system-wide PEBS event. The second PEBS event
is a per-thread event. When the thread is scheduled out, the
intel_pmu_pebs_del() function is invoked to update the PEBS state.
Since the system-wide event is still available, the cpuc->n_pebs is 1.
The cpuc->pebs_data_cfg is cleared. The data configuration for the
system-wide PEBS event is lost.
The (cpuc->n_pebs == 1) check was introduced in commit:
b6a32f023f ("perf/x86: Fix PEBS threshold initialization")
At that time, it indeed didn't hurt whether the state was updated
during the removal, because only the threshold is updated.
The calculation of the threshold takes the last PEBS event into
account.
However, since commit:
b752ea0c28 ("perf/x86/intel/ds: Flush PEBS DS when changing PEBS_DATA_CFG")
we delay the threshold update, and clear the PEBS data config, which triggers
the bug.
The PEBS data config update scope should not be shrunk during removal.
[ mingo: Improved the changelog & comments. ]
Fixes: b752ea0c28 ("perf/x86/intel/ds: Flush PEBS DS when changing PEBS_DATA_CFG")
Reported-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240401133320.703971-1-kan.liang@linux.intel.com
Tony encountered this OOPS when the last CPU of a domain goes
offline while running a kernel built with CONFIG_NO_HZ_FULL:
BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 0
Oops: 0000 [#1] PREEMPT SMP NOPTI
...
RIP: 0010:__find_nth_andnot_bit+0x66/0x110
...
Call Trace:
<TASK>
? __die()
? page_fault_oops()
? exc_page_fault()
? asm_exc_page_fault()
cpumask_any_housekeeping()
mbm_setup_overflow_handler()
resctrl_offline_cpu()
resctrl_arch_offline_cpu()
cpuhp_invoke_callback()
cpuhp_thread_fun()
smpboot_thread_fn()
kthread()
ret_from_fork()
ret_from_fork_asm()
</TASK>
The NULL pointer dereference is encountered while searching for another
online CPU in the domain (of which there are none) that can be used to
run the MBM overflow handler.
Because the kernel is configured with CONFIG_NO_HZ_FULL the search for
another CPU (in its effort to prefer those CPUs that aren't marked
nohz_full) consults the mask representing the nohz_full CPUs,
tick_nohz_full_mask. On a kernel with CONFIG_CPUMASK_OFFSTACK=y
tick_nohz_full_mask is not allocated unless the kernel is booted with
the "nohz_full=" parameter and because of that any access to
tick_nohz_full_mask needs to be guarded with tick_nohz_full_enabled().
Replace the IS_ENABLED(CONFIG_NO_HZ_FULL) with tick_nohz_full_enabled().
The latter ensures tick_nohz_full_mask can be accessed safely and can be
used whether kernel is built with CONFIG_NO_HZ_FULL enabled or not.
[ Use Ingo's suggestion that combines the two NO_HZ checks into one. ]
Fixes: a4846aaf39 ("x86/resctrl: Add cpumask_any_housekeeping() for limbo/overflow")
Reported-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Babu Moger <babu.moger@amd.com>
Link: https://lore.kernel.org/r/ff8dfc8d3dcb04b236d523d1e0de13d2ef585223.1711993956.git.reinette.chatre@intel.com
Closes: https://lore.kernel.org/lkml/ZgIFT5gZgIQ9A9G7@agluck-desk3/
Now that it's possible to capture LBR on AMD CPU from BPF at arbitrary
point, there is no reason to artificially limit this feature to just
sampling events. So corresponding check is removed. AFAIU, there is no
correctness implications of doing this (and it was possible to bypass
this check by just setting perf_event's sample_period to 1 anyways, so
it doesn't guard all that much).
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Sandipan Das <sandipan.das@amd.com>
Link: https://lore.kernel.org/r/20240402022118.1046049-5-andrii@kernel.org
Upstream commit c22ac2a3d4 ("perf: Enable branch record for software
events") added ability to capture LBR (Last Branch Records) on Intel CPUs
from inside BPF program at pretty much any arbitrary point. This is
extremely useful capability that allows to figure out otherwise
hard to debug problems, because LBR is now available based on some
application-defined conditions, not just hardware-supported events.
'retsnoop' is one such tool that takes a huge advantage of this
functionality and has proved to be an extremely useful tool in
practice:
https://github.com/anakryiko/retsnoop
Now, AMD Zen4 CPUs got support for similar LBR functionality, but
necessary wiring inside the kernel is not yet setup. This patch seeks to
rectify this and follows a similar approach to the original patch
for Intel CPUs. We implement an AMD-specific callback set to be called
through perf_snapshot_branch_stack static call.
Previous preparatory patches ensured that amd_pmu_core_disable_all() and
__amd_pmu_lbr_disable() will be completely inlined and will have no
branches, so LBR snapshot contamination will be minimized.
This was tested on AMD Bergamo CPU and worked well when utilized from
the aforementioned retsnoop tool.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Sandipan Das <sandipan.das@amd.com>
Link: https://lore.kernel.org/r/20240402022118.1046049-4-andrii@kernel.org
In the following patches we will enable LBR capture on AMD CPUs at
arbitrary point in time, which means that LBR recording won't be frozen
by hardware automatically as part of hardware overflow event. So we need
to take care to minimize amount of branches and function calls/returns
on the path to freezing LBR, minimizing LBR snapshot altering as much as
possible.
As such, split out LBR disabling logic from the sanity checking logic
inside amd_pmu_lbr_disable_all(). This will ensure that no branches are
taken before LBR is frozen in the functionality added in the next patch.
Use __always_inline to also eliminate any possible function calls.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Sandipan Das <sandipan.das@amd.com>
Link: https://lore.kernel.org/r/20240402022118.1046049-3-andrii@kernel.org
In the following patches we will enable LBR capture on AMD CPUs at
arbitrary point in time, which means that LBR recording won't be frozen
by hardware automatically as part of hardware overflow event. So we need
to take care to minimize amount of branches and function calls/returns
on the path to freezing LBR, minimizing LBR snapshot altering as much as
possible.
amd_pmu_core_disable_all() is one of the functions on this path, and is
already marked as __always_inline. But it calls amd_pmu_set_global_ctl()
which is marked as just inline. So to guarantee no function call will
be generated thoughout mark amd_pmu_set_global_ctl() as __always_inline
as well.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Sandipan Das <sandipan.das@amd.com>
Link: https://lore.kernel.org/r/20240402022118.1046049-2-andrii@kernel.org
-----BEGIN PGP SIGNATURE-----
iQFSBAABCAA8FiEEq68RxlopcLEwq+PEeb4+QwBBGIYFAmYJ1nceHHRvcnZhbGRz
QGxpbnV4LWZvdW5kYXRpb24ub3JnAAoJEHm+PkMAQRiGzPkH/jQ9hL1zS3XS+wJw
GthWkLl70quCueWkLaOYdhfPwJpRDVIrr7A533q1Hxp35nWx6bEJpmvBHys8Dm/x
5OOf595voL7UhdY+93k0IRyJBSMApBgW83AO6vqndpld95TrOxItdvlnpuXiqLxn
5S4vf5LSWE7B2k0iWq5Uv6UnBwQ19F9SB6d0ujLHYBp5VcwDuctIPrD+2+XYKBBf
/PWZtUgn4FeL6Ez1MJGs2qGSK8vxalqozqsrIr/LAQayhwGA+OM7Q/hqVQmjbek7
QdGJPRMsngbq+QxbMzKA5q57tM7RKnrZgnOi3hC/FWpHNXPPHdeBfnPqpRw+ovJA
qLvEBI0=
=2ioy
-----END PGP SIGNATURE-----
Merge tag 'v6.9-rc2' into perf/core, to pick up dependent commits
Pick up fixes that followup patches are going to depend on.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Commit:
b6540de9b5 ("x86/percpu: Disable named address spaces for KASAN")
... disabled support for named address spaces with KCSAN due to
the incompatibility issue between named AS and KCSAN.
GCC 13.3 has fixed this issue (GCC PR sanitizer/111736) so the
support for named address spaces can be re-enabled with sanitizers
for GCC compiler version >= 13.3.
[ Note that the patch considers GCC 14 to be fixed - if somebody is
using snapshots of the GCC 14 before the fix, they should upgrade. ]
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20240402121926.78477-1-ubizjak@gmail.com
Fix Sparse warning when casting from __percpu address space by using
__force in the cast. x86 named address spaces are not considered to
be subspaces of the generic (flat) address space, so explicit casts
are required to convert pointers between these address spaces and the
generic address space (the application should cast to uintptr_t and
apply the segment base offset). The cast to uintptr_t removes
__percpu address space tag and Sparse reports:
warning: cast removes address space '__percpu' of expression
Use __force to inform Sparse that the cast is intentional.
Fixes: 9a462b9eaf ("x86/percpu: Use compiler segment prefix qualifier")
Reported-by: Charlemagne Lasse <charlemagnelasse@gmail.com>
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20240402175058.52649-1-ubizjak@gmail.com
Closes: https://lore.kernel.org/lkml/CAFGhKbzev7W4aHwhFPWwMZQEHenVgZUj7=aunFieVqZg3mt14A@mail.gmail.com/
Currently for DeviceTree bootup, x86 code does the default mapping of
CPUs to NUMA, which is wrong. This can cause incorrect mapping and WARNs
on SMT enabled systems:
CPU #1's smt-sibling CPU #0 is not on the same node! [node: 1 != 0]. Ignoring dependency.
WARNING: CPU: 1 PID: 0 at topology_sane.isra.0+0x5c/0x6d
match_smt+0xf6/0xfc
set_cpu_sibling_map.cold+0x24f/0x512
start_secondary+0x5c/0x110
Call the set_apicid_to_node() function in dtb_cpu_setup() for setting
the NUMA to CPU mapping for DeviceTree platforms.
Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/1712068830-4513-4-git-send-email-ssengar@linux.microsoft.com
x86_dtb_parse_smp_config() must be set by DeviceTree platform for
parsing SMP configuration. Set the parse_smp_cfg pointer to
x86_dtb_parse_smp_config() by default so that all the dtb platforms
need not to assign it explicitly. Today there are only two platforms
using DeviceTree in x86, ce4100 and hv_vtl. Remove the explicit
assignment of x86_dtb_parse_smp_config() function from these.
Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/1712068830-4513-3-git-send-email-ssengar@linux.microsoft.com
VTL platform uses DeviceTree for fetching SMP configuration, assign
the correct parsing function x86_dtb_parse_smp_config() for it to
parse_smp_cfg.
Fixes: c22e19cd2c ("x86/hyperv/vtl: Prepare for separate mpparse callbacks")
Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/1712068830-4513-2-git-send-email-ssengar@linux.microsoft.com
- Ensure perf events programmed to count during guest execution
are actually enabled before entering the guest in the nVHE
configuration.
- Restore out-of-range handler for stage-2 translation faults.
- Several fixes to stage-2 TLB invalidations to avoid stale
translations, possibly including partial walk caches.
- Fix early handling of architectural VHE-only systems to ensure E2H is
appropriately set.
- Correct a format specifier warning in the arch_timer selftest.
- Make the KVM banner message correctly handle all of the possible
configurations.
-----BEGIN PGP SIGNATURE-----
iI0EABYIADUWIQSNXHjWXuzMZutrKNKivnWIJHzdFgUCZgtpWBccb2xpdmVyLnVw
dG9uQGxpbnV4LmRldgAKCRCivnWIJHzdFoilAQCQk6kLIeuih5QOe50fK4XkNsyg
PGcxw0a0BP8cfjtJsgEArwLlfHQOTE4tRWtXyEHvapJfe/bE1hjLmzUJx7BwLQ4=
=6hNq
-----END PGP SIGNATURE-----
Merge tag 'kvmarm-fixes-6.9-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD
KVM/arm64 fixes for 6.9, part #1
- Ensure perf events programmed to count during guest execution
are actually enabled before entering the guest in the nVHE
configuration.
- Restore out-of-range handler for stage-2 translation faults.
- Several fixes to stage-2 TLB invalidations to avoid stale
translations, possibly including partial walk caches.
- Fix early handling of architectural VHE-only systems to ensure E2H is
appropriately set.
- Correct a format specifier warning in the arch_timer selftest.
- Make the KVM banner message correctly handle all of the possible
configurations.
Since
32974ad490 ("[IA64] Remove COMPAT_IA32 support")
IA32_STACK_TOP and ia32_setup_arg_pages() are not used anymore.
And
675a081360 ("x86: unify mmap_{32|64}.c")
left behind ia32_pick_mmap_layout() extern declaration.
Remove them all.
[ bp: Massage commit message. ]
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20230625125411.25840-1-yuehaibing@huawei.com
The commit:
59bec00ace ("x86/percpu: Introduce %rip-relative addressing to PER_CPU_VAR()")
made PER_CPU_VAR() to use rip-relative addressing, hence
INCREMENT_CALL_DEPTH macro and skl_call_thunk_template got rip-relative
asm code inside of it. A follow up commit:
17bce3b2ae ("x86/callthunks: Handle %rip-relative relocations in call thunk template")
changed x86_call_depth_emit_accounting() to use apply_relocation(),
but mistakenly assumed that the code is being patched in-place (where
the destination of the relocation matches the address of the code),
using *pprog as the destination ip. This is not true for the call depth
accounting, emitted by the BPF JIT, so the calculated address was wrong,
JIT-ed BPF progs on kernels with call depth tracking got broken and
usually caused a page fault.
Pass the destination IP when the BPF JIT emits call depth accounting.
Fixes: 17bce3b2ae ("x86/callthunks: Handle %rip-relative relocations in call thunk template")
Signed-off-by: Joan Bruguera Micó <joanbrugueram@gmail.com>
Reviewed-by: Uros Bizjak <ubizjak@gmail.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/r/20240401185821.224068-3-ubizjak@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
David Hildenbrand