Commit graph

1574 commits

Author SHA1 Message Date
Paul Mackerras
31c8b0d069 KVM: PPC: Book3S HV: Use __gfn_to_pfn_memslot() in page fault handler
This changes the hypervisor page fault handler for radix guests to use
the generic KVM __gfn_to_pfn_memslot() function instead of using
get_user_pages_fast() and then handling the case of VM_PFNMAP vmas
specially.  The old code missed the case of VM_IO vmas; with this
change, VM_IO vmas will now be handled correctly by code within
__gfn_to_pfn_memslot.

Currently, __gfn_to_pfn_memslot calls hva_to_pfn, which only uses
__get_user_pages_fast for the initial lookup in the cases where
either atomic or async is set.  Since we are not setting either
atomic or async, we do our own __get_user_pages_fast first, for now.

This also adds code to check for the KVM_MEM_READONLY flag on the
memslot.  If it is set and this is a write access, we synthesize a
data storage interrupt for the guest.

In the case where the page is not normal RAM (i.e. page == NULL in
kvmppc_book3s_radix_page_fault(), we read the PTE from the Linux page
tables because we need the mapping attribute bits as well as the PFN.
(The mapping attribute bits indicate whether accesses have to be
non-cacheable and/or guarded.)

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-03-28 08:27:58 +11:00
Paul Mackerras
58c5c276b4 KVM: PPC: Book3S HV: Handle 1GB pages in radix page fault handler
This adds code to the radix hypervisor page fault handler to handle the
case where the guest memory is backed by 1GB hugepages, and put them
into the partition-scoped radix tree at the PUD level.  The code is
essentially analogous to the code for 2MB pages.  This also rearranges
kvmppc_create_pte() to make it easier to follow.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-03-19 10:08:53 +11:00
Paul Mackerras
f7caf712d8 KVM: PPC: Book3S HV: Streamline setting of reference and change bits
When using the radix MMU, we can get hypervisor page fault interrupts
with the DSISR_SET_RC bit set in DSISR/HSRR1, indicating that an
attempt to set the R (reference) or C (change) bit in a PTE atomically
failed.  Previously we would find the corresponding Linux PTE and
check the permission and dirty bits there, but this is not really
necessary since we only need to do what the hardware was trying to
do, namely set R or C atomically.  This removes the code that reads
the Linux PTE and just update the partition-scoped PTE, having first
checked that it is still present, and if the access is a write, that
the PTE still has write permission.

Furthermore, we now check whether any other relevant bits are set
in DSISR, and if there are, then we proceed with the rest of the
function in order to handle whatever condition they represent,
instead of returning to the guest as we did previously.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-03-19 10:08:44 +11:00
Paul Mackerras
c4c8a7643e KVM: PPC: Book3S HV: Radix page fault handler optimizations
This improves the handling of transparent huge pages in the radix
hypervisor page fault handler.  Previously, if a small page is faulted
in to a 2MB region of guest physical space, that means that there is
a page table pointer at the PMD level, which could never be replaced
by a leaf (2MB) PMD entry.  This adds the code to clear the PMD,
invlidate the page walk cache and free the page table page in this
situation, so that the leaf PMD entry can be created.

This also adds code to check whether a PMD or PTE being inserted is
the same as is already there (because of a race with another CPU that
faulted on the same page) and if so, we don't replace the existing
entry, meaning that we don't invalidate the PTE or PMD and do a TLB
invalidation.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-03-19 10:08:38 +11:00
Paul Mackerras
39c983ea0f KVM: PPC: Remove unused kvm_unmap_hva callback
Since commit fb1522e099 ("KVM: update to new mmu_notifier semantic
v2", 2017-08-31), the MMU notifier code in KVM no longer calls the
kvm_unmap_hva callback.  This removes the PPC implementations of
kvm_unmap_hva().

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-03-19 10:08:29 +11:00
Paul Mackerras
a8b48a4dcc KVM: PPC: Book3S HV: Fix trap number return from __kvmppc_vcore_entry
This fixes a bug where the trap number that is returned by
__kvmppc_vcore_entry gets corrupted.  The effect of the corruption
is that IPIs get ignored on POWER9 systems when the IPI is sent via
a doorbell interrupt to a CPU which is executing in a KVM guest.
The effect of the IPI being ignored is often that another CPU locks
up inside smp_call_function_many() (and if that CPU is holding a
spinlock, other CPUs then lock up inside raw_spin_lock()).

The trap number is currently held in register r12 for most of the
assembly-language part of the guest exit path.  In that path, we
call kvmppc_subcore_exit_guest(), which is a C function, without
restoring r12 afterwards.  Depending on the kernel config and the
compiler, it may modify r12 or it may not, so some config/compiler
combinations see the bug and others don't.

To fix this, we arrange for the trap number to be stored on the
stack from the 'guest_bypass:' label until the end of the function,
then the trap number is loaded and returned in r12 as before.

Cc: stable@vger.kernel.org # v4.8+
Fixes: fd7bacbca4 ("KVM: PPC: Book3S HV: Fix TB corruption in guest exit path on HMI interrupt")
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-03-14 15:10:50 +11:00
Radim Krčmář
db5679379a Fixes for PPC KVM:
- Fix guest time accounting in the host
 - Fix large-page backing for radix guests on POWER9
 - Fix HPT guests on POWER9 backed by 2M or 1G pages
 - Compile fixes for some configs and gcc versions
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQEcBAABAgAGBQJammR1AAoJEJ2a6ncsY3Gf2pQIAKf1sBKimpDj/yeBlWVbS41q
 6mIJh8R+4DV7TcOSVoOdzUz1dU1cseVznqqr3kexu+unoUpcqm240ZUDsDNWy9j0
 Xv0JyrGOcPor9sQmlb1s2gOsybxhic4u8Ih1eQV47bEUw1Rb84/da0JI1u5nMRTq
 nm3OHPGSnK2C8UkBBVjGelLJGUx+uaLFLjJSSTd0F9+hlxjGT3yXjP3wLG/ZNajT
 6Reuzpr95hGpmIaml8gh73clLk4WAjF3+5SyiLo5nlsXzvMnC0DyzaUrHocIo6i7
 nZxrx9UguzEdiUbuc5NEs4klTc+GPwMCfd+7z6vmtyw87A0sVOUgGWNGcZL60ew=
 =Wy2j
 -----END PGP SIGNATURE-----

Merge tag 'kvm-ppc-fixes-4.16-1' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc

Fixes for PPC KVM:

- Fix guest time accounting in the host
- Fix large-page backing for radix guests on POWER9
- Fix HPT guests on POWER9 backed by 2M or 1G pages
- Compile fixes for some configs and gcc versions
2018-03-06 17:24:09 +01:00
Laurent Vivier
61bd0f66ff KVM: PPC: Book3S HV: Fix guest time accounting with VIRT_CPU_ACCOUNTING_GEN
Since commit 8b24e69fc4 ("KVM: PPC: Book3S HV: Close race with testing
for signals on guest entry"), if CONFIG_VIRT_CPU_ACCOUNTING_GEN is set, the
guest time is not accounted to guest time and user time, but instead to
system time.

This is because guest_enter()/guest_exit() are called while interrupts
are disabled and the tick counter cannot be updated between them.

To fix that, move guest_exit() after local_irq_enable(), and as
guest_enter() is called with IRQ disabled, call guest_enter_irqoff()
instead.

Fixes: 8b24e69fc4 ("KVM: PPC: Book3S HV: Close race with testing for signals on guest entry")
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-03-03 19:28:34 +11:00
Paul Mackerras
debd574f41 KVM: PPC: Book3S HV: Fix VRMA initialization with 2MB or 1GB memory backing
The current code for initializing the VRMA (virtual real memory area)
for HPT guests requires the page size of the backing memory to be one
of 4kB, 64kB or 16MB.  With a radix host we have the possibility that
the backing memory page size can be 2MB or 1GB.  In these cases, if the
guest switches to HPT mode, KVM will not initialize the VRMA and the
guest will fail to run.

In fact it is not necessary that the VRMA page size is the same as the
backing memory page size; any VRMA page size less than or equal to the
backing memory page size is acceptable.  Therefore we now choose the
largest page size out of the set {4k, 64k, 16M} which is not larger
than the backing memory page size.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-03-02 15:38:24 +11:00
Paul Mackerras
c3856aeb29 KVM: PPC: Book3S HV: Fix handling of large pages in radix page fault handler
This fixes several bugs in the radix page fault handler relating to
the way large pages in the memory backing the guest were handled.
First, the check for large pages only checked for explicit huge pages
and missed transparent huge pages.  Then the check that the addresses
(host virtual vs. guest physical) had appropriate alignment was
wrong, meaning that the code never put a large page in the partition
scoped radix tree; it was always demoted to a small page.

Fixing this exposed bugs in kvmppc_create_pte().  We were never
invalidating a 2MB PTE, which meant that if a page was initially
faulted in without write permission and the guest then attempted
to store to it, we would never update the PTE to have write permission.
If we find a valid 2MB PTE in the PMD, we need to clear it and
do a TLB invalidation before installing either the new 2MB PTE or
a pointer to a page table page.

This also corrects an assumption that get_user_pages_fast would set
the _PAGE_DIRTY bit if we are writing, which is not true.  Instead we
mark the page dirty explicitly with set_page_dirty_lock().  This
also means we don't need the dirty bit set on the host PTE when
providing write access on a read fault.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-03-02 14:05:32 +11:00
Ingo Molnar
ed7158bae4 treewide/trivial: Remove ';;$' typo noise
On lkml suggestions were made to split up such trivial typo fixes into per subsystem
patches:

  --- a/arch/x86/boot/compressed/eboot.c
  +++ b/arch/x86/boot/compressed/eboot.c
  @@ -439,7 +439,7 @@ setup_uga32(void **uga_handle, unsigned long size, u32 *width, u32 *height)
          struct efi_uga_draw_protocol *uga = NULL, *first_uga;
          efi_guid_t uga_proto = EFI_UGA_PROTOCOL_GUID;
          unsigned long nr_ugas;
  -       u32 *handles = (u32 *)uga_handle;;
  +       u32 *handles = (u32 *)uga_handle;
          efi_status_t status = EFI_INVALID_PARAMETER;
          int i;

This patch is the result of the following script:

  $ sed -i 's/;;$/;/g' $(git grep -E ';;$'  | grep "\.[ch]:"  | grep -vwE 'for|ia64' | cut -d: -f1 | sort | uniq)

... followed by manual review to make sure it's all good.

Splitting this up is just crazy talk, let's get over with this and just do it.

Reported-by: Pavel Machek <pavel@ucw.cz>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-02-22 10:59:33 +01:00
Paul Mackerras
6df3877fc9 KVM: PPC: Book3S: Fix compile error that occurs with some gcc versions
Some versions of gcc generate a warning that the variable "emulated"
may be used uninitialized in function kvmppc_handle_load128_by2x64().
It would be used uninitialized if kvmppc_handle_load128_by2x64 was
ever called with vcpu->arch.mmio_vmx_copy_nums == 0, but neither of
the callers ever do that, so there is no actual bug.  When gcc
generates a warning, it causes the build to fail because arch/powerpc
is compiled with -Werror.

This silences the warning by initializing "emulated" to EMULATE_DONE.

Fixes: 09f984961c ("KVM: PPC: Book3S: Add MMIO emulation for VMX instructions")
Reported-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-02-13 15:45:21 +11:00
Paul Mackerras
c662f77331 KVM: PPC: Fix compile error that occurs when CONFIG_ALTIVEC=n
Commit accb757d79 ("KVM: Move vcpu_load to arch-specific
kvm_arch_vcpu_ioctl_run", 2017-12-04) added a "goto out"
statement and an "out:" label to kvm_arch_vcpu_ioctl_run().
Since the only "goto out" is inside a CONFIG_VSX block,
compiling with CONFIG_VSX=n gives a warning that label "out"
is defined but not used, and because arch/powerpc is compiled
with -Werror, that becomes a compile error that makes the kernel
build fail.

Merge commit 1ab03c072f ("Merge tag 'kvm-ppc-next-4.16-2' of
git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc",
2018-02-09) added a similar block of code inside a #ifdef
CONFIG_ALTIVEC, with a "goto out" statement.

In order to make the build succeed, this adds a #ifdef around the
"out:" label.  This is a minimal, ugly fix, to be replaced later
by a refactoring of the code.  Since CONFIG_VSX depends on
CONFIG_ALTIVEC, it is sufficient to use #ifdef CONFIG_ALTIVEC here.

Fixes: accb757d79 ("KVM: Move vcpu_load to arch-specific kvm_arch_vcpu_ioctl_run")
Reported-by: Christian Zigotzky <chzigotzky@xenosoft.de>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-02-13 15:23:39 +11:00
Linus Torvalds
15303ba5d1 KVM changes for 4.16
ARM:
 - Include icache invalidation optimizations, improving VM startup time
 
 - Support for forwarded level-triggered interrupts, improving
   performance for timers and passthrough platform devices
 
 - A small fix for power-management notifiers, and some cosmetic changes
 
 PPC:
 - Add MMIO emulation for vector loads and stores
 
 - Allow HPT guests to run on a radix host on POWER9 v2.2 CPUs without
   requiring the complex thread synchronization of older CPU versions
 
 - Improve the handling of escalation interrupts with the XIVE interrupt
   controller
 
 - Support decrement register migration
 
 - Various cleanups and bugfixes.
 
 s390:
 - Cornelia Huck passed maintainership to Janosch Frank
 
 - Exitless interrupts for emulated devices
 
 - Cleanup of cpuflag handling
 
 - kvm_stat counter improvements
 
 - VSIE improvements
 
 - mm cleanup
 
 x86:
 - Hypervisor part of SEV
 
 - UMIP, RDPID, and MSR_SMI_COUNT emulation
 
 - Paravirtualized TLB shootdown using the new KVM_VCPU_PREEMPTED bit
 
 - Allow guests to see TOPOEXT, GFNI, VAES, VPCLMULQDQ, and more AVX512
   features
 
 - Show vcpu id in its anonymous inode name
 
 - Many fixes and cleanups
 
 - Per-VCPU MSR bitmaps (already merged through x86/pti branch)
 
 - Stable KVM clock when nesting on Hyper-V (merged through x86/hyperv)
 -----BEGIN PGP SIGNATURE-----
 
 iQEcBAABCAAGBQJafvMtAAoJEED/6hsPKofo6YcH/Rzf2RmshrWaC3q82yfIV0Qz
 Z8N8yJHSaSdc3Jo6cmiVj0zelwAxdQcyjwlT7vxt5SL2yML+/Q0st9Hc3EgGGXPm
 Il99eJEl+2MYpZgYZqV8ff3mHS5s5Jms+7BITAeh6Rgt+DyNbykEAvzt+MCHK9cP
 xtsIZQlvRF7HIrpOlaRzOPp3sK2/MDZJ1RBE7wYItK3CUAmsHim/LVYKzZkRTij3
 /9b4LP1yMMbziG+Yxt1o682EwJB5YIat6fmDG9uFeEVI5rWWN7WFubqs8gCjYy/p
 FX+BjpOdgTRnX+1m9GIj0Jlc/HKMXryDfSZS07Zy4FbGEwSiI5SfKECub4mDhuE=
 =C/uD
 -----END PGP SIGNATURE-----

Merge tag 'kvm-4.16-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM updates from Radim Krčmář:
 "ARM:

   - icache invalidation optimizations, improving VM startup time

   - support for forwarded level-triggered interrupts, improving
     performance for timers and passthrough platform devices

   - a small fix for power-management notifiers, and some cosmetic
     changes

  PPC:

   - add MMIO emulation for vector loads and stores

   - allow HPT guests to run on a radix host on POWER9 v2.2 CPUs without
     requiring the complex thread synchronization of older CPU versions

   - improve the handling of escalation interrupts with the XIVE
     interrupt controller

   - support decrement register migration

   - various cleanups and bugfixes.

  s390:

   - Cornelia Huck passed maintainership to Janosch Frank

   - exitless interrupts for emulated devices

   - cleanup of cpuflag handling

   - kvm_stat counter improvements

   - VSIE improvements

   - mm cleanup

  x86:

   - hypervisor part of SEV

   - UMIP, RDPID, and MSR_SMI_COUNT emulation

   - paravirtualized TLB shootdown using the new KVM_VCPU_PREEMPTED bit

   - allow guests to see TOPOEXT, GFNI, VAES, VPCLMULQDQ, and more
     AVX512 features

   - show vcpu id in its anonymous inode name

   - many fixes and cleanups

   - per-VCPU MSR bitmaps (already merged through x86/pti branch)

   - stable KVM clock when nesting on Hyper-V (merged through
     x86/hyperv)"

* tag 'kvm-4.16-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (197 commits)
  KVM: PPC: Book3S: Add MMIO emulation for VMX instructions
  KVM: PPC: Book3S HV: Branch inside feature section
  KVM: PPC: Book3S HV: Make HPT resizing work on POWER9
  KVM: PPC: Book3S HV: Fix handling of secondary HPTEG in HPT resizing code
  KVM: PPC: Book3S PR: Fix broken select due to misspelling
  KVM: x86: don't forget vcpu_put() in kvm_arch_vcpu_ioctl_set_sregs()
  KVM: PPC: Book3S PR: Fix svcpu copying with preemption enabled
  KVM: PPC: Book3S HV: Drop locks before reading guest memory
  kvm: x86: remove efer_reload entry in kvm_vcpu_stat
  KVM: x86: AMD Processor Topology Information
  x86/kvm/vmx: do not use vm-exit instruction length for fast MMIO when running nested
  kvm: embed vcpu id to dentry of vcpu anon inode
  kvm: Map PFN-type memory regions as writable (if possible)
  x86/kvm: Make it compile on 32bit and with HYPYERVISOR_GUEST=n
  KVM: arm/arm64: Fixup userspace irqchip static key optimization
  KVM: arm/arm64: Fix userspace_irqchip_in_use counting
  KVM: arm/arm64: Fix incorrect timer_is_pending logic
  MAINTAINERS: update KVM/s390 maintainers
  MAINTAINERS: add Halil as additional vfio-ccw maintainer
  MAINTAINERS: add David as a reviewer for KVM/s390
  ...
2018-02-10 13:16:35 -08:00
Radim Krčmář
1ab03c072f Second PPC KVM update for 4.16
Seven fixes that are either trivial or that address bugs that people
 are actually hitting.  The main ones are:
 
 - Drop spinlocks before reading guest memory
 
 - Fix a bug causing corruption of VCPU state in PR KVM with preemption
   enabled
 
 - Make HPT resizing work on POWER9
 
 - Add MMIO emulation for vector loads and stores, because guests now
   use these instructions in memcpy and similar routines.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQEcBAABAgAGBQJafWn0AAoJEJ2a6ncsY3GfaMsIANF0hQD8SS78WNKnoy0vnZ/X
 PUXdjwHEsfkg5KdQ7o0oaa2BJHHqO3vozddmMiG14r2L1mNCHJpnVZCVV0GaEJcZ
 eU8++OPK6yrsPNNpAjnrtQ0Vk4LwzoT0bftEjS3TtLt1s2uSo+R1+HLmxbxGhQUX
 bZngo9wQ3cjUfAXLrPtAVhE5wTmgVOiufVRyfRsBRdFzRsAWqjY4hBtJAfwdff4r
 AA5H0RCrXO6e1feKr5ElU8KzX6b7IjH9Xu868oJ1r16zZfE05PBl1X5n4XG7XDm7
 xWvs8uLAB7iRv2o/ecFznYJ+Dz1NCBVzD0RmAUTqPCcVKDrxixaTkqMPFW97IAA=
 =HOJR
 -----END PGP SIGNATURE-----

Merge tag 'kvm-ppc-next-4.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc

Second PPC KVM update for 4.16

Seven fixes that are either trivial or that address bugs that people
are actually hitting.  The main ones are:

- Drop spinlocks before reading guest memory

- Fix a bug causing corruption of VCPU state in PR KVM with preemption
  enabled

- Make HPT resizing work on POWER9

- Add MMIO emulation for vector loads and stores, because guests now
  use these instructions in memcpy and similar routines.
2018-02-09 22:03:06 +01:00
Jose Ricardo Ziviani
09f984961c KVM: PPC: Book3S: Add MMIO emulation for VMX instructions
This patch provides the MMIO load/store vector indexed
X-Form emulation.

Instructions implemented:
lvx: the quadword in storage addressed by the result of EA &
0xffff_ffff_ffff_fff0 is loaded into VRT.

stvx: the contents of VRS are stored into the quadword in storage
addressed by the result of EA & 0xffff_ffff_ffff_fff0.

Reported-by: Gopesh Kumar Chaudhary <gopchaud@in.ibm.com>
Reported-by: Balamuruhan S <bala24@linux.vnet.ibm.com>
Signed-off-by: Jose Ricardo Ziviani <joserz@linux.vnet.ibm.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-02-09 16:51:51 +11:00
Alexander Graf
d20fe50a7b KVM: PPC: Book3S HV: Branch inside feature section
We ended up with code that did a conditional branch inside a feature
section to code outside of the feature section. Depending on how the
object file gets organized, that might mean we exceed the 14bit
relocation limit for conditional branches:

  arch/powerpc/kvm/built-in.o:arch/powerpc/kvm/book3s_hv_rmhandlers.S:416:(__ftr_alt_97+0x8): relocation truncated to fit: R_PPC64_REL14 against `.text'+1ca4

So instead of doing a conditional branch outside of the feature section,
let's just jump at the end of the same, making the branch very short.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-02-09 15:39:41 +11:00
David Gibson
790a9df5fb KVM: PPC: Book3S HV: Make HPT resizing work on POWER9
This adds code to enable the HPT resizing code to work on POWER9,
which uses a slightly modified HPT entry format compared to POWER8.
On POWER9, we convert HPTEs read from the HPT from the new format to
the old format so that the rest of the HPT resizing code can work as
before.  HPTEs written to the new HPT are converted to the new format
as the last step before writing them into the new HPT.

This takes out the checks added by commit bcd3bb63db ("KVM: PPC:
Book3S HV: Disable HPT resizing on POWER9 for now", 2017-02-18),
now that HPT resizing works on POWER9.

On POWER9, when we pivot to the new HPT, we now call
kvmppc_setup_partition_table() to update the partition table in order
to make the hardware use the new HPT.

[paulus@ozlabs.org - added kvmppc_setup_partition_table() call,
 wrote commit message.]

Tested-by: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-02-09 15:36:36 +11:00
Paul Mackerras
05f2bb0313 KVM: PPC: Book3S HV: Fix handling of secondary HPTEG in HPT resizing code
This fixes the computation of the HPTE index to use when the HPT
resizing code encounters a bolted HPTE which is stored in its
secondary HPTE group.  The code inverts the HPTE group number, which
is correct, but doesn't then mask it with new_hash_mask.  As a result,
new_pteg will be effectively negative, resulting in new_hptep
pointing before the new HPT, which will corrupt memory.

In addition, this removes two BUG_ON statements.  The condition that
the BUG_ONs were testing -- that we have computed the hash value
incorrectly -- has never been observed in testing, and if it did
occur, would only affect the guest, not the host.  Given that
BUG_ON should only be used in conditions where the kernel (i.e.
the host kernel, in this case) can't possibly continue execution,
it is not appropriate here.

Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-02-09 15:35:24 +11:00
Ulf Magnusson
57ea5f161a KVM: PPC: Book3S PR: Fix broken select due to misspelling
Commit 76d837a4c0 ("KVM: PPC: Book3S PR: Don't include SPAPR TCE code
on non-pseries platforms") added a reference to the globally undefined
symbol PPC_SERIES. Looking at the rest of the commit, PPC_PSERIES was
probably intended.

Change PPC_SERIES to PPC_PSERIES.

Discovered with the
https://github.com/ulfalizer/Kconfiglib/blob/master/examples/list_undefined.py
script.

Fixes: 76d837a4c0 ("KVM: PPC: Book3S PR: Don't include SPAPR TCE code on non-pseries platforms")
Cc: stable@vger.kernel.org # v4.12+
Signed-off-by: Ulf Magnusson <ulfalizer@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-02-08 16:42:16 +11:00
Linus Torvalds
03f51d4efa powerpc updates for 4.16
Highlights:
 
  - Enable support for memory protection keys aka "pkeys" on Power7/8/9 when
    using the hash table MMU.
 
  - Extend our interrupt soft masking to support masking PMU interrupts as well
    as "normal" interrupts, and then use that to implement local_t for a ~4x
    speedup vs the current atomics-based implementation.
 
  - A new driver "ocxl" for "Open Coherent Accelerator Processor Interface
    (OpenCAPI)" devices.
 
  - Support for new device tree properties on PowerVM to describe hotpluggable
    memory and devices.
 
  - Add support for CLOCK_{REALTIME/MONOTONIC}_COARSE to the 64-bit VDSO.
 
  - Freescale updates from Scott:
      "Contains fixes for CPM GPIO and an FSL PCI erratum workaround, plus a
       minor cleanup patch."
 
 As well as quite a lot of other changes all over the place, and small fixes and
 cleanups as always.
 
 Thanks to:
   Alan Modra, Alastair D'Silva, Alexey Kardashevskiy, Alistair Popple, Andreas
   Schwab, Andrew Donnellan, Aneesh Kumar K.V, Anju T Sudhakar, Anshuman
   Khandual, Anton Blanchard, Arnd Bergmann, Balbir Singh, Benjamin
   Herrenschmidt, Bhaktipriya Shridhar, Bryant G. Ly, Cédric Le Goater,
   Christophe Leroy, Christophe Lombard, Cyril Bur, David Gibson, Desnes A. Nunes
   do Rosario, Dmitry Torokhov, Frederic Barrat, Geert Uytterhoeven, Guilherme G.
   Piccoli, Gustavo A. R. Silva, Gustavo Romero, Ivan Mikhaylov, Joakim
   Tjernlund, Joe Perches, Josh Poimboeuf, Juan J. Alvarez, Julia Cartwright,
   Kamalesh Babulal, Madhavan Srinivasan, Mahesh Salgaonkar, Mathieu Malaterre,
   Michael Bringmann, Michael Hanselmann, Michael Neuling, Nathan Fontenot,
   Naveen N. Rao, Nicholas Piggin, Paul Mackerras, Philippe Bergheaud, Ram Pai,
   Russell Currey, Santosh Sivaraj, Scott Wood, Seth Forshee, Simon Guo, Stewart
   Smith, Sukadev Bhattiprolu, Thiago Jung Bauermann, Vaibhav Jain, Vasyl
   Gomonovych.
 -----BEGIN PGP SIGNATURE-----
 
 iQIwBAABCAAaBQJadF6wExxtcGVAZWxsZXJtYW4uaWQuYXUACgkQUevqPMjhpYA2
 nBAAnguCEyAIYpc+ffE3WU9xJEWxa6bKuVufHcUFVntGiGD+igmMS+SHp4ay3Aos
 HcA4WFrpzNb2KZ++kmFWtAKWnMfCiW9xuYJNicjr7X5ZiVBEhLWN/mQCwBKs3p6L
 5+HhvytcdkKVbEcyVjEGvRL40AyxXNOI02o6Co9X8vanHsmWB4q0eWe4PHstZqlg
 6K6kazMp+NTvEFYwKNXDOvuHouKSL57l14SLROH7CpJkNTOQ9s+W59/LmnuCjRlu
 o70b7iWOAEbF9tvMma1ksDZVNj7mSyaymLYCyOXu4CkuuleJacZYJ9oQGNddoIbC
 wk7l93vPT/yze7DYg8x3uXpKcaDEvEepPuQ/ubz+UXFQWuJtl5ej6Cv+0eOmyZIs
 +bjWhGHKdNttnsiPlTRCX/gWD13RE1dB6xXJlfOJ7Oz9OnXXK8ZKc1NTREbQXRWM
 8tClAwf9upWpm86GHPVnyrgYbgZo5b1os4SoS8e3kESzakrQVQP7J376u2DtccRq
 2AGqjJ+tl5tYPnhm8zG1cNrpqHHpgkNGqLS7DvWRg3EPmEKVQcltN1b/0aKaAjHA
 aTRofjrVo+jJ4MX1uyEo59yNCEQPfjkmHRQdLwm+xjWTzEPfIMzpWyXm14tawDQf
 OjcAe90W/qQ18brw4z+2BI14J76XziOSX/QcunOn1u/sqaM=
 =3rYn
 -----END PGP SIGNATURE-----

Merge tag 'powerpc-4.16-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc updates from Michael Ellerman:
 "Highlights:

   - Enable support for memory protection keys aka "pkeys" on Power7/8/9
     when using the hash table MMU.

   - Extend our interrupt soft masking to support masking PMU interrupts
     as well as "normal" interrupts, and then use that to implement
     local_t for a ~4x speedup vs the current atomics-based
     implementation.

   - A new driver "ocxl" for "Open Coherent Accelerator Processor
     Interface (OpenCAPI)" devices.

   - Support for new device tree properties on PowerVM to describe
     hotpluggable memory and devices.

   - Add support for CLOCK_{REALTIME/MONOTONIC}_COARSE to the 64-bit
     VDSO.

   - Freescale updates from Scott: fixes for CPM GPIO and an FSL PCI
     erratum workaround, plus a minor cleanup patch.

  As well as quite a lot of other changes all over the place, and small
  fixes and cleanups as always.

  Thanks to: Alan Modra, Alastair D'Silva, Alexey Kardashevskiy,
  Alistair Popple, Andreas Schwab, Andrew Donnellan, Aneesh Kumar K.V,
  Anju T Sudhakar, Anshuman Khandual, Anton Blanchard, Arnd Bergmann,
  Balbir Singh, Benjamin Herrenschmidt, Bhaktipriya Shridhar, Bryant G.
  Ly, Cédric Le Goater, Christophe Leroy, Christophe Lombard, Cyril Bur,
  David Gibson, Desnes A. Nunes do Rosario, Dmitry Torokhov, Frederic
  Barrat, Geert Uytterhoeven, Guilherme G. Piccoli, Gustavo A. R. Silva,
  Gustavo Romero, Ivan Mikhaylov, Joakim Tjernlund, Joe Perches, Josh
  Poimboeuf, Juan J. Alvarez, Julia Cartwright, Kamalesh Babulal,
  Madhavan Srinivasan, Mahesh Salgaonkar, Mathieu Malaterre, Michael
  Bringmann, Michael Hanselmann, Michael Neuling, Nathan Fontenot,
  Naveen N. Rao, Nicholas Piggin, Paul Mackerras, Philippe Bergheaud,
  Ram Pai, Russell Currey, Santosh Sivaraj, Scott Wood, Seth Forshee,
  Simon Guo, Stewart Smith, Sukadev Bhattiprolu, Thiago Jung Bauermann,
  Vaibhav Jain, Vasyl Gomonovych"

* tag 'powerpc-4.16-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (199 commits)
  powerpc/mm/radix: Fix build error when RADIX_MMU=n
  macintosh/ams-input: Use true and false for boolean values
  macintosh: change some data types from int to bool
  powerpc/watchdog: Print the NIP in soft_nmi_interrupt()
  powerpc/watchdog: regs can't be null in soft_nmi_interrupt()
  powerpc/watchdog: Tweak watchdog printks
  powerpc/cell: Remove axonram driver
  rtc-opal: Fix handling of firmware error codes, prevent busy loops
  powerpc/mpc52xx_gpt: make use of raw_spinlock variants
  macintosh/adb: Properly mark continued kernel messages
  powerpc/pseries: Fix cpu hotplug crash with memoryless nodes
  powerpc/numa: Ensure nodes initialized for hotplug
  powerpc/numa: Use ibm,max-associativity-domains to discover possible nodes
  powerpc/kernel: Block interrupts when updating TIDR
  powerpc/powernv/idoa: Remove unnecessary pcidev from pci_dn
  powerpc/mm/nohash: do not flush the entire mm when range is a single page
  powerpc/pseries: Add Initialization of VF Bars
  powerpc/pseries/pci: Associate PEs to VFs in configure SR-IOV
  powerpc/eeh: Add EEH notify resume sysfs
  powerpc/eeh: Add EEH operations to notify resume
  ...
2018-02-02 10:01:04 -08:00
Radim Krčmář
d2b9b2079e PPC KVM update for 4.16
- Allow HPT guests to run on a radix host on POWER9 v2.2 CPUs
   without requiring the complex thread synchronization that earlier
   CPU versions required.
 
 - A series from Ben Herrenschmidt to improve the handling of
   escalation interrupts with the XIVE interrupt controller.
 
 - Provide for the decrementer register to be copied across on
   migration.
 
 - Various minor cleanups and bugfixes.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQEcBAABAgAGBQJaYXViAAoJEJ2a6ncsY3GfDhgIAIDVBZH/Ftq7eJiUSxDpqyCQ
 DF/x7fNKzK/J33pu+3ntOI2gZsldExAy7vH2M27I4qLIkbI5y3vu4v8l3CDlS1LK
 9dKi72zg7baozoVF5mGUNm0B1sSvZiIQlC/kaami2aPTF1GcrJ561GthzfZwxENX
 TSLqOA4LkeUZh2tUsvbcUrPi6v+E4Em2lgacQcx2ioMblWz56sZu79VsUbSSw/a3
 P8+pIv7EbHw+TrOZMehjCbZkOdBeZ3IRLJsdlIAfe7y4vWME/5b9uVnQS/+XQj/B
 6f3rQrduGvF2P6GMjsm8gDkgE5oZ1zbKlgO4i5WApnu80MMLFlfEUN+GWuGJ95Q=
 =OjGs
 -----END PGP SIGNATURE-----

Merge tag 'kvm-ppc-next-4.16-1' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc

PPC KVM update for 4.16

- Allow HPT guests to run on a radix host on POWER9 v2.2 CPUs
  without requiring the complex thread synchronization that earlier
  CPU versions required.

- A series from Ben Herrenschmidt to improve the handling of
  escalation interrupts with the XIVE interrupt controller.

- Provide for the decrementer register to be copied across on
  migration.

- Various minor cleanups and bugfixes.
2018-02-01 16:13:07 +01:00
Radim Krčmář
7bf14c28ee Merge branch 'x86/hyperv' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Topic branch for stable KVM clockource under Hyper-V.

Thanks to Christoffer Dall for resolving the ARM conflict.
2018-02-01 15:04:17 +01:00
Linus Torvalds
40b9672a2f Merge branch 'work.whack-a-mole' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull asm/uaccess.h whack-a-mole from Al Viro:
 "It's linux/uaccess.h, damnit... Oh, well - eventually they'll stop
  cropping up..."

* 'work.whack-a-mole' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  asm-prototypes.h: use linux/uaccess.h, not asm/uaccess.h
  riscv: use linux/uaccess.h, not asm/uaccess.h...
  ppc: for put_user() pull linux/uaccess.h, not asm/uaccess.h
2018-01-31 19:18:12 -08:00
Alexander Graf
07ae5389e9 KVM: PPC: Book3S PR: Fix svcpu copying with preemption enabled
When copying between the vcpu and svcpu, we may get scheduled away onto
a different host CPU which in turn means our svcpu pointer may change.

That means we need to atomically copy to and from the svcpu with preemption
disabled, so that all code around it always sees a coherent state.

Reported-by: Simon Guo <wei.guo.simon@gmail.com>
Fixes: 3d3319b45e ("KVM: PPC: Book3S: PR: Enable interrupts earlier")
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-02-01 13:35:33 +11:00
Paul Mackerras
36ee41d161 KVM: PPC: Book3S HV: Drop locks before reading guest memory
Running with CONFIG_DEBUG_ATOMIC_SLEEP reveals that HV KVM tries to
read guest memory, in order to emulate guest instructions, while
preempt is disabled and a vcore lock is held.  This occurs in
kvmppc_handle_exit_hv(), called from post_guest_process(), when
emulating guest doorbell instructions on POWER9 systems, and also
when checking whether we have hit a hypervisor breakpoint.
Reading guest memory can cause a page fault and thus cause the
task to sleep, so we need to avoid reading guest memory while
holding a spinlock or when preempt is disabled.

To fix this, we move the preempt_enable() in kvmppc_run_core() to
before the loop that calls post_guest_process() for each vcore that
has just run, and we drop and re-take the vcore lock around the calls
to kvmppc_emulate_debug_inst() and kvmppc_emulate_doorbell_instr().

Dropping the lock is safe with respect to the iteration over the
runnable vcpus in post_guest_process(); for_each_runnable_thread
is actually safe to use locklessly.  It is possible for a vcpu
to become runnable and add itself to the runnable_threads array
(code near the beginning of kvmppc_run_vcpu()) and then get included
in the iteration in post_guest_process despite the fact that it
has not just run.  This is benign because vcpu->arch.trap and
vcpu->arch.ceded will be zero.

Cc: stable@vger.kernel.org # v4.13+
Fixes: 579006944e ("KVM: PPC: Book3S HV: Virtualize doorbell facility on POWER9")
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-02-01 13:35:33 +11:00
Russell Currey
57ad583f20 powerpc: Use octal numbers for file permissions
Symbolic macros are unintuitive and hard to read, whereas octal constants
are much easier to interpret.  Replace macros for the basic permission
flags (user/group/other read/write/execute) with numeric constants
instead, across the whole powerpc tree.

Introducing a significant number of changes across the tree for no runtime
benefit isn't exactly desirable, but so long as these macros are still
used in the tree people will keep sending patches that add them.  Not only
are they hard to parse at a glance, there are multiple ways of coming to
the same value (as you can see with 0444 and 0644 in this patch) which
hurts readability.

Signed-off-by: Russell Currey <ruscur@russell.cc>
Reviewed-by: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-22 05:48:33 +11:00
Michael Ellerman
ebf0b6a8b1 Merge branch 'fixes' into next
Merge our fixes branch from the 4.15 cycle.

Unusually the fixes branch saw some significant features merged,
notably the RFI flush patches, so we want the code in next to be
tested against that, to avoid any surprises when the two are merged.

There's also some other work on the panic handling that was reverted
in fixes and we now want to do properly in next, which would conflict.

And we also fix a few other minor merge conflicts.
2018-01-21 23:21:14 +11:00
Michael Ellerman
5400fc229e Merge branch 'topic/ppc-kvm' into next
Merge the topic branch we share with kvm-ppc, this brings in two xive
commits, one from Paul to rework HMI handling, and a minor cleanup to
drop an unused flag.
2018-01-21 22:43:43 +11:00
Aneesh Kumar K.V
76b03dc07e powerpc/mm: Remove unused flag arg in global_invalidates
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-21 20:30:44 +11:00
Madhavan Srinivasan
4e26bc4a4e powerpc/64: Rename soft_enabled to irq_soft_mask
Rename the paca->soft_enabled to paca->irq_soft_mask as it is no
longer used as a flag for interrupt state, but a mask.

Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-19 22:37:01 +11:00
Paul Mackerras
3214d01f13 KVM: PPC: Book3S: Provide information about hardware/firmware CVE workarounds
This adds a new ioctl, KVM_PPC_GET_CPU_CHAR, that gives userspace
information about the underlying machine's level of vulnerability
to the recently announced vulnerabilities CVE-2017-5715,
CVE-2017-5753 and CVE-2017-5754, and whether the machine provides
instructions to assist software to work around the vulnerabilities.

The ioctl returns two u64 words describing characteristics of the
CPU and required software behaviour respectively, plus two mask
words which indicate which bits have been filled in by the kernel,
for extensibility.  The bit definitions are the same as for the
new H_GET_CPU_CHARACTERISTICS hypercall.

There is also a new capability, KVM_CAP_PPC_GET_CPU_CHAR, which
indicates whether the new ioctl is available.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-01-19 15:17:01 +11:00
Benjamin Herrenschmidt
9b9b13a6d1 KVM: PPC: Book3S HV: Keep XIVE escalation interrupt masked unless ceded
This works on top of the single escalation support. When in single
escalation, with this change, we will keep the escalation interrupt
disabled unless the VCPU is in H_CEDE (idle). In any other case, we
know the VCPU will be rescheduled and thus there is no need to take
escalation interrupts in the host whenever a guest interrupt fires.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-01-19 12:10:21 +11:00
Benjamin Herrenschmidt
35c2405efc KVM: PPC: Book3S HV: Make xive_pushed a byte, not a word
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-01-19 12:10:21 +11:00
Benjamin Herrenschmidt
2662efd050 KVM: PPC: Book3S HV: Check DR not IR to chose real vs virt mode MMIOs
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-01-19 12:10:21 +11:00
Benjamin Herrenschmidt
2267ea7661 KVM: PPC: Book3S HV: Don't use existing "prodded" flag for XIVE escalations
The prodded flag is only cleared at the beginning of H_CEDE,
so every time we have an escalation, we will cause the *next*
H_CEDE to return immediately.

Instead use a dedicated "irq_pending" flag to indicate that
a guest interrupt is pending for the VCPU. We don't reuse the
existing exception bitmap so as to avoid expensive atomic ops.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-01-19 12:10:21 +11:00
Benjamin Herrenschmidt
bf4159da47 KVM: PPC: Book3S HV: Enable use of the new XIVE "single escalation" feature
That feature, provided by Power9 DD2.0 and later, when supported
by newer OPAL versions, allows us to sacrifice a queue (priority 7)
in favor of merging all the escalation interrupts of the queues
of a single VP into a single interrupt.

This reduces the number of host interrupts used up by KVM guests
especially when those guests use multiple priorities.

It will also enable a future change to control the masking of the
escalation interrupts more precisely to avoid spurious ones.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-01-19 12:10:21 +11:00
Benjamin Herrenschmidt
c424c10823 KVM: PPC: Book3S HV: Add more info about XIVE queues in debugfs
Add details about enabled queues and escalation interrupts.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-01-19 12:10:21 +11:00
Paul Mackerras
d27998185d Merge remote-tracking branch 'remotes/powerpc/topic/ppc-kvm' into kvm-ppc-next
This merges in the ppc-kvm topic branch of the powerpc tree to get
two patches which are prerequisites for the following patch series,
plus another patch which touches both powerpc and KVM code.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-01-19 12:09:57 +11:00
Paul Mackerras
d075745d89 KVM: PPC: Book3S HV: Improve handling of debug-trigger HMIs on POWER9
Hypervisor maintenance interrupts (HMIs) are generated by various
causes, signalled by bits in the hypervisor maintenance exception
register (HMER).  In most cases calling OPAL to handle the interrupt
is the correct thing to do, but the "debug trigger" HMIs signalled by
PPC bit 17 (bit 46) of HMER are used to invoke software workarounds
for hardware bugs, and OPAL does not have any code to handle this
cause.  The debug trigger HMI is used in POWER9 DD2.0 and DD2.1 chips
to work around a hardware bug in executing vector load instructions to
cache inhibited memory.  In POWER9 DD2.2 chips, it is generated when
conditions are detected relating to threads being in TM (transactional
memory) suspended mode when the core SMT configuration needs to be
reconfigured.

The kernel currently has code to detect the vector CI load condition,
but only when the HMI occurs in the host, not when it occurs in a
guest.  If a HMI occurs in the guest, it is always passed to OPAL, and
then we always re-sync the timebase, because the HMI cause might have
been a timebase error, for which OPAL would re-sync the timebase, thus
removing the timebase offset which KVM applied for the guest.  Since
we don't know what OPAL did, we don't know whether to subtract the
timebase offset from the timebase, so instead we re-sync the timebase.

This adds code to determine explicitly what the cause of a debug
trigger HMI will be.  This is based on a new device-tree property
under the CPU nodes called ibm,hmi-special-triggers, if it is
present, or otherwise based on the PVR (processor version register).
The handling of debug trigger HMIs is pulled out into a separate
function which can be called from the KVM guest exit code.  If this
function handles and clears the HMI, and no other HMI causes remain,
then we skip calling OPAL and we proceed to subtract the guest
timebase offset from the timebase.

The overall handling for HMIs that occur in the host (i.e. not in a
KVM guest) is largely unchanged, except that we now don't set the flag
for the vector CI load workaround on DD2.2 processors.

This also removes a BUG_ON in the KVM code.  BUG_ON is generally not
useful in KVM guest entry/exit code since it is difficult to handle
the resulting trap gracefully.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-18 15:31:25 +11:00
Paul Mackerras
00608e1f00 KVM: PPC: Book3S HV: Allow HPT and radix on the same core for POWER9 v2.2
POWER9 chip versions starting with "Nimbus" v2.2 can support running
with some threads of a core in HPT mode and others in radix mode.
This means that we don't have to prohibit independent-threads mode
when running a HPT guest on a radix host, and we don't have to do any
of the synchronization between threads that was introduced in commit
c01015091a ("KVM: PPC: Book3S HV: Run HPT guests on POWER9 radix
hosts", 2017-10-19).

Rather than using up another CPU feature bit, we just do an
explicit test on the PVR (processor version register) at module
startup time to determine whether we have to take steps to avoid
having some threads in HPT mode and some in radix mode (so-called
"mixed mode").  We test for "Nimbus" (indicated by 0 or 1 in the top
nibble of the lower 16 bits) v2.2 or later, or "Cumulus" (indicated by
2 or 3 in that nibble) v1.1 or later.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-01-18 12:05:19 +11:00
Nicholas Piggin
d4748276ae powerpc/64s: Improve local TLB flush for boot and MCE on POWER9
There are several cases outside the normal address space management
where a CPU's entire local TLB is to be flushed:

  1. Booting the kernel, in case something has left stale entries in
     the TLB (e.g., kexec).

  2. Machine check, to clean corrupted TLB entries.

One other place where the TLB is flushed, is waking from deep idle
states. The flush is a side-effect of calling ->cpu_restore with the
intention of re-setting various SPRs. The flush itself is unnecessary
because in the first case, the TLB should not acquire new corrupted
TLB entries as part of sleep/wake (though they may be lost).

This type of TLB flush is coded inflexibly, several times for each CPU
type, and they have a number of problems with ISA v3.0B:

- The current radix mode of the MMU is not taken into account, it is
  always done as a hash flushn For IS=2 (LPID-matching flush from host)
  and IS=3 with HV=0 (guest kernel flush), tlbie(l) is undefined if
  the R field does not match the current radix mode.

- ISA v3.0B hash must flush the partition and process table caches as
  well.

- ISA v3.0B radix must flush partition and process scoped translations,
  partition and process table caches, and also the page walk cache.

So consolidate the flushing code and implement it in C and inline asm
under the mm/ directory with the rest of the flush code. Add ISA v3.0B
cases for radix and hash, and use the radix flush in radix environment.

Provide a way for IS=2 (LPID flush) to specify the radix mode of the
partition. Have KVM pass in the radix mode of the guest.

Take out the flushes from early cputable/dt_cpu_ftrs detection hooks,
and move it later in the boot process after, the MMU registers are set
up and before relocation is first turned on.

The TLB flush is no longer called when restoring from deep idle states.
This was not be done as a separate step because booting secondaries
uses the same cpu_restore as idle restore, which needs the TLB flush.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-18 00:40:31 +11:00
Paul Mackerras
6964e6a4e4 KVM: PPC: Book3S HV: Do SLB load/unload with guest LPCR value loaded
This moves the code that loads and unloads the guest SLB values so that
it is done while the guest LPCR value is loaded in the LPCR register.
The reason for doing this is that on POWER9, the behaviour of the
slbmte instruction depends on the LPCR[UPRT] bit.  If UPRT is 1, as
it is for a radix host (or guest), the SLB index is truncated to
2 bits.  This means that for a HPT guest on a radix host, the SLB
was not being loaded correctly, causing the guest to crash.

The SLB is now loaded much later in the guest entry path, after the
LPCR is loaded, which for a secondary thread is after it sees that
the primary thread has switched the MMU to the guest.  The loop that
waits for the primary thread has a branch out to the exit code that
is taken if it sees that other threads have commenced exiting the
guest.  Since we have now not loaded the SLB at this point, we make
this path branch to a new label 'guest_bypass' and we move the SLB
unload code to before this label.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-01-17 11:19:02 +11:00
Paul Mackerras
43ff3f6523 KVM: PPC: Book3S HV: Make sure we don't re-enter guest without XIVE loaded
This fixes a bug where it is possible to enter a guest on a POWER9
system without having the XIVE (interrupt controller) context loaded.
This can happen because we unload the XIVE context from the CPU
before doing the real-mode handling for machine checks.  After the
real-mode handler runs, it is possible that we re-enter the guest
via a fast path which does not load the XIVE context.

To fix this, we move the unloading of the XIVE context to come after
the real-mode machine check handler is called.

Fixes: 5af5099385 ("KVM: PPC: Book3S HV: Native usage of the XIVE interrupt controller")
Cc: stable@vger.kernel.org # v4.11+
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-01-17 11:18:48 +11:00
Paul Mackerras
5855564c8a KVM: PPC: Book3S HV: Enable migration of decrementer register
This adds a register identifier for use with the one_reg interface
to allow the decrementer expiry time to be read and written by
userspace.  The decrementer expiry time is in guest timebase units
and is equal to the sum of the decrementer and the guest timebase.
(The expiry time is used rather than the decrementer value itself
because the expiry time is not constantly changing, though the
decrementer value is, while the guest vcpu is not running.)

Without this, a guest vcpu migrated to a new host will see its
decrementer set to some random value.  On POWER8 and earlier, the
decrementer is 32 bits wide and counts down at 512MHz, so the
guest vcpu will potentially see no decrementer interrupts for up
to about 4 seconds, which will lead to a stall.  With POWER9, the
decrementer is now 56 bits side, so the stall can be much longer
(up to 2.23 years) and more noticeable.

To help work around the problem in cases where userspace has not been
updated to migrate the decrementer expiry time, we now set the
default decrementer expiry at vcpu creation time to the current time
rather than the maximum possible value.  This should mean an
immediate decrementer interrupt when a migrated vcpu starts
running.  In cases where the decrementer is 32 bits wide and more
than 4 seconds elapse between the creation of the vcpu and when it
first runs, the decrementer would have wrapped around to positive
values and there may still be a stall - but this is no worse than
the current situation.  In the large-decrementer case, we are sure
to get an immediate decrementer interrupt (assuming the time from
vcpu creation to first run is less than 2.23 years) and we thus
avoid a very long stall.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-01-16 11:54:45 +11:00
Linus Torvalds
6bb821193b powerpc fixes for 4.15 #7
One fix for an oops at boot if we take a hotplug interrupt before we are ready
 to handle it.
 
 The bulk is patches to implement mitigation for Meltdown, see the change logs
 for more details.
 
 Thanks to:
   Nicholas Piggin, Michael Neuling, Oliver O'Halloran, Jon Masters, Jose Ricardo
   Ziviani, David Gibson.
 -----BEGIN PGP SIGNATURE-----
 
 iQIwBAABCAAaBQJaWXZ+ExxtcGVAZWxsZXJtYW4uaWQuYXUACgkQUevqPMjhpYBe
 ew/+KMp80VAIGSyFeYHLg8oClnQjKcEDMzlNoHo8WU6NwwNzk2XXBXNaGT7Osg7B
 Ny69R3/VRrGmi/2uule9OzF2eZt8BUmRn3cHDcUB5OwFjMysv4M2jc+OK0STQxLU
 F769rX+ZlkyAvQn4UxtNCUob+JDfVbE5Lurrx475ZGL1YHk6QqBGhlN/niXKtkBz
 upeBEpu4JgwsLLD9H7c4QQha9PkhxY51jtvxL24cgwDuKJKhTdxLahPlA3QmLafu
 FJxR9R0YzTj9Ivuae5yM7xRKr5wROTPtTRbG9sN7XOgFNrQ+LSgemXGrlV/fzdhV
 6iPn2hHs4bu45SOIM+Hhf7OwHTtnMetXmKo6NldlKHVCw1HwBLigRohnOTPjiHfZ
 P6brR4T/cglakBiE29+8T0UFqOPizEJiQRHnsoWzwIa/aTqCGEE3m3rgTxU6ovt5
 3JggC51ZRDFsjGvj+JFnxGxCjYC4tDbfBI28M+GuWZZPBKLkFnEk8PlSzYyHPW2p
 5uVA/UN4KHVGYUfJVUC+LMP+ZIOSEyEISKk7RuK0C0mwHSXcvxbeEefXbc18Xjai
 J/pl/c9/4CRnEbdPm305xBxKKmU6gWxWRK3KbRFsoTI/wp+Ryx5TjPpgAa5GnaLv
 nrtrfKs8skWfGMoDWH7+KILt0fgRR2x+91GTSxc5aaHtYBI=
 =UZHv
 -----END PGP SIGNATURE-----

Merge tag 'powerpc-4.15-7' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc fixes from Michael Ellerman:
 "One fix for an oops at boot if we take a hotplug interrupt before we
  are ready to handle it.

  The bulk is patches to implement mitigation for Meltdown, see the
  change logs for more details.

  Thanks to: Nicholas Piggin, Michael Neuling, Oliver O'Halloran, Jon
  Masters, Jose Ricardo Ziviani, David Gibson"

* tag 'powerpc-4.15-7' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/powernv: Check device-tree for RFI flush settings
  powerpc/pseries: Query hypervisor for RFI flush settings
  powerpc/64s: Support disabling RFI flush with no_rfi_flush and nopti
  powerpc/64s: Add support for RFI flush of L1-D cache
  powerpc/64s: Convert slb_miss_common to use RFI_TO_USER/KERNEL
  powerpc/64: Convert fast_exception_return to use RFI_TO_USER/KERNEL
  powerpc/64: Convert the syscall exit path to use RFI_TO_USER/KERNEL
  powerpc/64s: Simple RFI macro conversions
  powerpc/64: Add macros for annotating the destination of rfid/hrfid
  powerpc/pseries: Add H_GET_CPU_CHARACTERISTICS flags & wrapper
  powerpc/pseries: Make RAS IRQ explicitly dependent on DLPAR WQ
2018-01-14 15:03:17 -08:00
Paolo Bonzini
0217690f88 PPC KVM fixes for 4.15
Four commits here, including two that were tagged but never merged.
 Three of them are for the HPT resizing code; two of those fix a
 user-triggerable use-after-free in the host, and one that fixes
 stale TLB entries in the guest.  The remaining commit fixes a bug
 causing PR KVM guests under PowerVM to fail to start.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQEcBAABAgAGBQJaVfPgAAoJEJ2a6ncsY3GfA10IANZMkwtIpqxGlsAeXKr5bWdl
 iXYD9ymb2/FOHBbg6v8Eh6Gb1ycjzXpXqn74/Y9TE4Ort7mdiH+W6kXYEsMqL8yg
 7Uwnj8DuWFuFxX0x0V4SJQzgdCnOefVcfoo/RnLUzmLsW0Vqtr3A1djM5iHlxFvv
 ntkNtGYPOoaHl6rjtfHTDfLWN/DzEJbaIU/0O1LIkBxPG4STzSXErAucLL46Pa/X
 NuPO2HfpxQiacHVG62iy89eJeAcraEAXnH5e6eVPRQQqh3DSIERMU6n6jXyZeMU5
 NWX8Qme3VGBpiJOiCGMvMrnJmQmMTSWTtkGljyaFy+vZWMqGZ6xJ3wIP+5t9d+Q=
 =dw6K
 -----END PGP SIGNATURE-----

Merge tag 'kvm-ppc-fixes-4.15-3' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc into kvm-master

PPC KVM fixes for 4.15

Four commits here, including two that were tagged but never merged.
Three of them are for the HPT resizing code; two of those fix a
user-triggerable use-after-free in the host, and one that fixes
stale TLB entries in the guest.  The remaining commit fixes a bug
causing PR KVM guests under PowerVM to fail to start.
2018-01-11 14:07:27 +01:00
Markus Elfring
1627301020 KVM: PPC: Use seq_puts() in kvmppc_exit_timing_show()
A headline should be quickly put into a sequence. Thus use the
function "seq_puts" instead of "seq_printf" for this purpose.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-01-11 20:36:06 +11:00
Alexander Graf
81ceca05a4 KVM: PPC: Book3S HV: Remove vcpu->arch.dec usage
On Book3S in HV mode, we don't use the vcpu->arch.dec field at all.
Instead, all logic is built around vcpu->arch.dec_expires.

So let's remove the one remaining piece of code that was setting it.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-01-11 20:36:06 +11:00
David Gibson
ecba8297aa KVM: PPC: Book3S HV: Always flush TLB in kvmppc_alloc_reset_hpt()
The KVM_PPC_ALLOCATE_HTAB ioctl(), implemented by kvmppc_alloc_reset_hpt()
is supposed to completely clear and reset a guest's Hashed Page Table (HPT)
allocating or re-allocating it if necessary.

In the case where an HPT of the right size already exists and it just
zeroes it, it forces a TLB flush on all guest CPUs, to remove any stale TLB
entries loaded from the old HPT.

However, that situation can arise when the HPT is resizing as well - or
even when switching from an RPT to HPT - so those cases need a TLB flush as
well.

So, move the TLB flush to trigger in all cases except for errors.

Cc: stable@vger.kernel.org # v4.10+
Fixes: f98a8bf9ee ("KVM: PPC: Book3S HV: Allow KVM_PPC_ALLOCATE_HTAB ioctl() to change HPT size")
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-01-10 20:45:41 +11:00