For ring-based dirty log tracking, it will be more efficient to account
writes during schedule-out or schedule-in to the currently running VCPU.
We would like to do it even if the write doesn't use the current VCPU's
address space, as is the case for cached writes (see commit 4e335d9e7d,
"Revert "KVM: Support vCPU-based gfn->hva cache"", 2017-05-02).
Therefore, add a mechanism to track the currently-loaded kvm_vcpu struct.
There is already something similar in KVM/ARM; one important difference
is that kvm_arch_vcpu_{load,put} have two callers in virt/kvm/kvm_main.c:
we have to update both the architecture-independent vcpu_{load,put} and
the preempt notifiers.
Another change made in the process is to allow using kvm_get_running_vcpu()
in preemptible code. This is allowed because preempt notifiers ensure
that the value does not change even after the VCPU thread is migrated.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Remove kvm_read_guest_atomic() because it's not used anywhere.
Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Remove kvm_arch_vcpu_init() and kvm_arch_vcpu_uninit() now that all
arch specific implementations are nops.
Acked-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Remove kvm_arch_vcpu_setup() now that all arch specific implementations
are nops.
Acked-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Unexport kvm_vcpu_cache and kvm_vcpu_{un}init() and make them static
now that they are referenced only in kvm_main.c.
Acked-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Now that all architectures tightly couple vcpu allocation/free with the
mandatory calls to kvm_{un}init_vcpu(), move the sequences verbatim to
common KVM code.
Move both allocation and initialization in a single patch to eliminate
thrash in arch specific code. The bisection benefits of moving the two
pieces in separate patches is marginal at best, whereas the odds of
introducing a transient arch specific bug are non-zero.
Acked-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add kvm_vcpu_destroy() and wire up all architectures to call the common
function instead of their arch specific implementation. The common
destruction function will be used by future patches to move allocation
and initialization of vCPUs to common KVM code, i.e. to free resources
that are allocated by arch agnostic code.
No functional change intended.
Acked-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add a pre-allocation arch hook to handle checks that are currently done
by arch specific code prior to allocating the vCPU object. This paves
the way for moving the allocation to common KVM code.
Acked-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Remove KVM's declaration of kvm_arch_vcpu_free() now that the function
is gone from all architectures (several architectures were relying on
the forward declaration).
Acked-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
We can store reference to kvm_stats_debugfs_item instead of copying
its values to kvm_stat_data.
This allows us to remove duplicated code and usage of temporary
kvm_stat_data inside vm_stat_get et al.
Signed-off-by: Milan Pandurov <milanpa@amazon.de>
Reviewed-by: Alexander Graf <graf@amazon.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Convert a plethora of parameters and variables in the MMU and page fault
flows from type gva_t to gpa_t to properly handle TDP on 32-bit KVM.
Thanks to PSE and PAE paging, 32-bit kernels can access 64-bit physical
addresses. When TDP is enabled, the fault address is a guest physical
address and thus can be a 64-bit value, even when both KVM and its guest
are using 32-bit virtual addressing, e.g. VMX's VMCS.GUEST_PHYSICAL is a
64-bit field, not a natural width field.
Using a gva_t for the fault address means KVM will incorrectly drop the
upper 32-bits of the GPA. Ditto for gva_to_gpa() when it is used to
translate L2 GPAs to L1 GPAs.
Opportunistically rename variables and parameters to better reflect the
dual address modes, e.g. use "cr2_or_gpa" for fault addresses and plain
"addr" instead of "vaddr" when the address may be either a GVA or an L2
GPA. Similarly, use "gpa" in the nonpaging_page_fault() flows to avoid
a confusing "gpa_t gva" declaration; this also sets the stage for a
future patch to combing nonpaging_page_fault() and tdp_page_fault() with
minimal churn.
Sprinkle in a few comments to document flows where an address is known
to be a GVA and thus can be safely truncated to a 32-bit value. Add
WARNs in kvm_handle_page_fault() and FNAME(gva_to_gpa_nested)() to help
document such cases and detect bugs.
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
There are two declarations of kvm_vcpu_kick() in kvm_host.h where
one of them is redundant. Remove to keep the git grep a bit cleaner.
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Zenghui Yu <yuzenghui@huawei.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Replace all the occurrences of FIELD_SIZEOF() with sizeof_field() except
at places where these are defined. Later patches will remove the unused
definition of FIELD_SIZEOF().
This patch is generated using following script:
EXCLUDE_FILES="include/linux/stddef.h|include/linux/kernel.h"
git grep -l -e "\bFIELD_SIZEOF\b" | while read file;
do
if [[ "$file" =~ $EXCLUDE_FILES ]]; then
continue
fi
sed -i -e 's/\bFIELD_SIZEOF\b/sizeof_field/g' $file;
done
Signed-off-by: Pankaj Bharadiya <pankaj.laxminarayan.bharadiya@intel.com>
Link: https://lore.kernel.org/r/20190924105839.110713-3-pankaj.laxminarayan.bharadiya@intel.com
Co-developed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: David Miller <davem@davemloft.net> # for net
- Allow non-ISV data aborts to be reported to userspace
- Allow injection of data aborts from userspace
- Expose stolen time to guests
- GICv4 performance improvements
- vgic ITS emulation fixes
- Simplify FWB handling
- Enable halt pool counters
- Make the emulated timer PREEMPT_RT compliant
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Merge tag 'kvmarm-5.5' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD
KVM/arm updates for Linux 5.5:
- Allow non-ISV data aborts to be reported to userspace
- Allow injection of data aborts from userspace
- Expose stolen time to guests
- GICv4 performance improvements
- vgic ITS emulation fixes
- Simplify FWB handling
- Enable halt pool counters
- Make the emulated timer PREEMPT_RT compliant
Conflicts:
include/uapi/linux/kvm.h
In IOAPIC fixed delivery mode instead of flushing the scan
requests to all vCPUs, we should only send the requests to
vCPUs specified within the destination field.
This patch introduces kvm_get_dest_vcpus_mask() API which
retrieves an array of target vCPUs by using
kvm_apic_map_get_dest_lapic() and then based on the
vcpus_idx, it sets the bit in a bitmap. However, if the above
fails kvm_get_dest_vcpus_mask() finds the target vCPUs by
traversing all available vCPUs. Followed by setting the
bits in the bitmap.
If we had different vCPUs in the previous request for the
same redirection table entry then bits corresponding to
these vCPUs are also set. This to done to keep
ioapic_handled_vectors synchronized.
This bitmap is then eventually passed on to
kvm_make_vcpus_request_mask() to generate a masked request
only for the target vCPUs.
This would enable us to reduce the latency overhead on isolated
vCPUs caused by the IPI to process due to KVM_REQ_IOAPIC_SCAN.
Suggested-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Nitesh Narayan Lal <nitesh@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Fetching an index for any vcpu in kvm->vcpus array by traversing
the entire array everytime is costly.
This patch remembers the position of each vcpu in kvm->vcpus array
by storing it in vcpus_idx under kvm_vcpu structure.
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Nitesh Narayan Lal <nitesh@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
VT-d posted interrupts, DAX/ZONE_DEVICE,
module unload/reload.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm fixes from Paolo Bonzini:
"Fix unwinding of KVM_CREATE_VM failure, VT-d posted interrupts,
DAX/ZONE_DEVICE, and module unload/reload"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: MMU: Do not treat ZONE_DEVICE pages as being reserved
KVM: VMX: Introduce pi_is_pir_empty() helper
KVM: VMX: Do not change PID.NDST when loading a blocked vCPU
KVM: VMX: Consider PID.PIR to determine if vCPU has pending interrupts
KVM: VMX: Fix comment to specify PID.ON instead of PIR.ON
KVM: X86: Fix initialization of MSR lists
KVM: fix placement of refcount initialization
KVM: Fix NULL-ptr deref after kvm_create_vm fails
Explicitly exempt ZONE_DEVICE pages from kvm_is_reserved_pfn() and
instead manually handle ZONE_DEVICE on a case-by-case basis. For things
like page refcounts, KVM needs to treat ZONE_DEVICE pages like normal
pages, e.g. put pages grabbed via gup(). But for flows such as setting
A/D bits or shifting refcounts for transparent huge pages, KVM needs to
to avoid processing ZONE_DEVICE pages as the flows in question lack the
underlying machinery for proper handling of ZONE_DEVICE pages.
This fixes a hang reported by Adam Borowski[*] in dev_pagemap_cleanup()
when running a KVM guest backed with /dev/dax memory, as KVM straight up
doesn't put any references to ZONE_DEVICE pages acquired by gup().
Note, Dan Williams proposed an alternative solution of doing put_page()
on ZONE_DEVICE pages immediately after gup() in order to simplify the
auditing needed to ensure is_zone_device_page() is called if and only if
the backing device is pinned (via gup()). But that approach would break
kvm_vcpu_{un}map() as KVM requires the page to be pinned from map() 'til
unmap() when accessing guest memory, unlike KVM's secondary MMU, which
coordinates with mmu_notifier invalidations to avoid creating stale
page references, i.e. doesn't rely on pages being pinned.
[*] http://lkml.kernel.org/r/20190919115547.GA17963@angband.pl
Reported-by: Adam Borowski <kilobyte@angband.pl>
Analyzed-by: David Hildenbrand <david@redhat.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Cc: stable@vger.kernel.org
Fixes: 3565fce3a6 ("mm, x86: get_user_pages() for dax mappings")
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add a function to create a kernel thread associated with a given VM. In
particular, it ensures that the worker thread inherits the priority and
cgroups of the calling thread.
Signed-off-by: Junaid Shahid <junaids@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Add a new helper, kvm_put_kvm_no_destroy(), to handle putting a borrowed
reference[*] to the VM when installing a new file descriptor fails. KVM
expects the refcount to remain valid in this case, as the in-progress
ioctl() has an explicit reference to the VM. The primary motiviation
for the helper is to document that the 'kvm' pointer is still valid
after putting the borrowed reference, e.g. to document that doing
mutex(&kvm->lock) immediately after putting a ref to kvm isn't broken.
[*] When exposing a new object to userspace via a file descriptor, e.g.
a new vcpu, KVM grabs a reference to itself (the VM) prior to making
the object visible to userspace to avoid prematurely freeing the VM
in the scenario where userspace immediately closes file descriptor.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The kvm_vcpu variable, guest_xcr0_loaded, is a waste of an 'int'
and a conditional branch. VMX and SVM are the only users, and both
unconditionally pair kvm_load_guest_xcr0() with kvm_put_guest_xcr0()
making this check unnecessary. Without this variable, the predicates in
kvm_load_guest_xcr0 and kvm_put_guest_xcr0 should match.
Suggested-by: Sean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Aaron Lewis <aaronlewis@google.com>
Change-Id: I7b1eb9b62969d7bbb2850f27e42f863421641b23
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Currently a kvm_device_ops structure cannot be const without triggering
compiler warnings. However the structure doesn't need to be written to
and, by marking it const, it can be read-only in memory. Add some more
const keywords to allow this.
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Steven Price <steven.price@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
kvm_put_guest() is analogous to put_user() - it writes a single value to
the guest physical address. The implementation is built upon put_user()
and so it has the same single copy atomic properties.
Signed-off-by: Steven Price <steven.price@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
The largepages debugfs entry is incremented/decremented as shadow
pages are created or destroyed. Clearing it will result in an
underflow, which is harmless to KVM but ugly (and could be
misinterpreted by tools that use debugfs information), so make
this particular statistic read-only.
Cc: kvm-ppc@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
When calling debugfs functions, there is no need to ever check the
return value. The function can work or not, but the code logic should
never do something different based on this.
Also, when doing this, change kvm_arch_create_vcpu_debugfs() to return
void instead of an integer, as we should not care at all about if this
function actually does anything or not.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Radim Krčmář" <rkrcmar@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: <x86@kernel.org>
Cc: <kvm@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
There is no need for this function as all arches have to implement
kvm_arch_create_vcpu_debugfs() no matter what. A #define symbol
let us actually simplify the code.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
After commit d73eb57b80 (KVM: Boost vCPUs that are delivering interrupts), a
five years old bug is exposed. Running ebizzy benchmark in three 80 vCPUs VMs
on one 80 pCPUs Skylake server, a lot of rcu_sched stall warning splatting
in the VMs after stress testing:
INFO: rcu_sched detected stalls on CPUs/tasks: { 4 41 57 62 77} (detected by 15, t=60004 jiffies, g=899, c=898, q=15073)
Call Trace:
flush_tlb_mm_range+0x68/0x140
tlb_flush_mmu.part.75+0x37/0xe0
tlb_finish_mmu+0x55/0x60
zap_page_range+0x142/0x190
SyS_madvise+0x3cd/0x9c0
system_call_fastpath+0x1c/0x21
swait_active() sustains to be true before finish_swait() is called in
kvm_vcpu_block(), voluntarily preempted vCPUs are taken into account
by kvm_vcpu_on_spin() loop greatly increases the probability condition
kvm_arch_vcpu_runnable(vcpu) is checked and can be true, when APICv
is enabled the yield-candidate vCPU's VMCS RVI field leaks(by
vmx_sync_pir_to_irr()) into spinning-on-a-taken-lock vCPU's current
VMCS.
This patch fixes it by checking conservatively a subset of events.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Marc Zyngier <Marc.Zyngier@arm.com>
Cc: stable@vger.kernel.org
Fixes: 98f4a1467 (KVM: add kvm_arch_vcpu_runnable() test to kvm_vcpu_on_spin() loop)
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Inspired by commit 9cac38dd5d (KVM/s390: Set preempted flag during
vcpu wakeup and interrupt delivery), we want to also boost not just
lock holders but also vCPUs that are delivering interrupts. Most
smp_call_function_many calls are synchronous, so the IPI target vCPUs
are also good yield candidates. This patch introduces vcpu->ready to
boost vCPUs during wakeup and interrupt delivery time; unlike s390 we do
not reuse vcpu->preempted so that voluntarily preempted vCPUs are taken
into account by kvm_vcpu_on_spin, but vmx_vcpu_pi_put is not affected
(VT-d PI handles voluntary preemption separately, in pi_pre_block).
Testing on 80 HT 2 socket Xeon Skylake server, with 80 vCPUs VM 80GB RAM:
ebizzy -M
vanilla boosting improved
1VM 21443 23520 9%
2VM 2800 8000 180%
3VM 1800 3100 72%
Testing on my Haswell desktop 8 HT, with 8 vCPUs VM 8GB RAM, two VMs,
one running ebizzy -M, the other running 'stress --cpu 2':
w/ boosting + w/o pv sched yield(vanilla)
vanilla boosting improved
1570 4000 155%
w/ boosting + w/ pv sched yield(vanilla)
vanilla boosting improved
1844 5157 179%
w/o boosting, perf top in VM:
72.33% [kernel] [k] smp_call_function_many
4.22% [kernel] [k] call_function_i
3.71% [kernel] [k] async_page_fault
w/ boosting, perf top in VM:
38.43% [kernel] [k] smp_call_function_many
6.31% [kernel] [k] async_page_fault
6.13% libc-2.23.so [.] __memcpy_avx_unaligned
4.88% [kernel] [k] call_function_interrupt
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Paul Mackerras <paulus@ozlabs.org>
Cc: Marc Zyngier <maz@kernel.org>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
- Add support for chained PMU counters in guests
- Improve SError handling
- Handle Neoverse N1 erratum #1349291
- Allow side-channel mitigation status to be migrated
- Standardise most AArch64 system register accesses to msr_s/mrs_s
- Fix host MPIDR corruption on 32bit
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Merge tag 'kvm-arm-for-5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD
KVM/arm updates for 5.3
- Add support for chained PMU counters in guests
- Improve SError handling
- Handle Neoverse N1 erratum #1349291
- Allow side-channel mitigation status to be migrated
- Standardise most AArch64 system register accesses to msr_s/mrs_s
- Fix host MPIDR corruption on 32bit
We get a warning when build kernel W=1:
arch/x86/kvm/../../../virt/kvm/eventfd.c:48:1: warning: no previous prototype for ‘kvm_arch_irqfd_allowed’ [-Wmissing-prototypes]
kvm_arch_irqfd_allowed(struct kvm *kvm, struct kvm_irqfd *args)
^
The reason is kvm_arch_irqfd_allowed() is declared in arch/x86/kvm/irq.h,
which is not included by eventfd.c. Considering kvm_arch_irqfd_allowed()
is a weakly defined function in eventfd.c, remove the declaration to
kvm_host.h can fix this.
Signed-off-by: Yi Wang <wang.yi59@zte.com.cn>
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Based on 1 normalized pattern(s):
this work is licensed under the terms of the gnu gpl version 2 see
the copying file in the top level directory
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 35 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.797835076@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
It doesn't seem as if there is any particular need for kvm_lock to be a
spinlock, so convert the lock to a mutex so that sleepable functions (in
particular cond_resched()) can be called while holding it.
Signed-off-by: Junaid Shahid <junaids@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add a wrapper to invoke kvm_arch_check_processor_compat() so that the
boilerplate ugliness of checking virtualization support on all CPUs is
hidden from the arch specific code. x86's implementation in particular
is quite heinous, as it unnecessarily propagates the out-param pattern
into kvm_x86_ops.
While the x86 specific issue could be resolved solely by changing
kvm_x86_ops, make the change for all architectures as returning a value
directly is prettier and technically more robust, e.g. s390 doesn't set
the out param, which could lead to subtle breakage in the (highly
unlikely) scenario where the out-param was not pre-initialized by the
caller.
Opportunistically annotate svm_check_processor_compat() with __init.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
- Fix a bug, fix a spelling mistake, remove some useless code.
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Merge tag 'kvm-ppc-next-5.2-2' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc into HEAD
PPC KVM update for 5.2
* Support for guests to access the new POWER9 XIVE interrupt controller
hardware directly, reducing interrupt latency and overhead for guests.
* In-kernel implementation of the H_PAGE_INIT hypercall.
* Reduce memory usage of sparsely-populated IOMMU tables.
* Several bug fixes.
Second PPC KVM update for 5.2
* Fix a bug, fix a spelling mistake, remove some useless code.
In KVM, specially for nested guests, there is a dominant pattern of:
=> map guest memory -> do_something -> unmap guest memory
In addition to all this unnecessarily noise in the code due to boiler plate
code, most of the time the mapping function does not properly handle memory
that is not backed by "struct page". This new guest mapping API encapsulate
most of this boiler plate code and also handles guest memory that is not
backed by "struct page".
The current implementation of this API is using memremap for memory that is
not backed by a "struct page" which would lead to a huge slow-down if it
was used for high-frequency mapping operations. The API does not have any
effect on current setups where guest memory is backed by a "struct page".
Further patches are going to also introduce a pfn-cache which would
significantly improve the performance of the memremap case.
Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
- VSIE crypto fixes
- new guest features for gen15
- disable halt polling for nested virtualization with overcommit
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Merge tag 'kvm-s390-next-5.2-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD
KVM: s390: Features and fixes for 5.2
- VSIE crypto fixes
- new guest features for gen15
- disable halt polling for nested virtualization with overcommit
When a P9 sPAPR VM boots, the CAS negotiation process determines which
interrupt mode to use (XICS legacy or XIVE native) and invokes a
machine reset to activate the chosen mode.
To be able to switch from one interrupt mode to another, we introduce
the capability to release a KVM device without destroying the VM. The
KVM device interface is extended with a new 'release' method which is
called when the file descriptor of the device is closed.
Once 'release' is called, the 'destroy' method will not be called
anymore as the device is removed from the device list of the VM.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Some KVM devices will want to handle special mappings related to the
underlying HW. For instance, the XIVE interrupt controller of the
POWER9 processor has MMIO pages for thread interrupt management and
for interrupt source control that need to be exposed to the guest when
the OS has the required support.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
There are cases where halt polling is unwanted. For example when running
KVM on an over committed LPAR we rather want to give back the CPU to
neighbour LPARs instead of polling. Let us provide a callback that
allows architectures to disable polling.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
The hard-coded value 10000 in grow_halt_poll_ns() stands for the initial
start value when raising up vcpu->halt_poll_ns.
It actually sets the first timeout to the first polling session.
This value has significant effect on how tolerant we are to outliers.
On the standard case, higher value is better - we will spend more time
in the polling busyloop, handle events/interrupts faster and result
in better performance.
But on outliers it puts us in a busy loop that does nothing.
Even if the shrink factor is zero, we will still waste time on the first
iteration.
The optimal value changes between different workloads. It depends on
outliers rate and polling sessions length.
As this value has significant effect on the dynamic halt-polling
algorithm, it should be configurable and exposed.
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Nir Weiner <nir.weiner@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
...now that KVM won't explode by moving it out of bit 0. Using bit 63
eliminates the need to jump over bit 0, e.g. when calculating a new
memslots generation or when propagating the memslots generation to an
MMIO spte.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM uses bit 0 of the memslots generation as an "update in-progress"
flag, which is used by x86 to prevent caching MMIO access while the
memslots are changing. Although the intended behavior is flag-like,
e.g. MMIO sptes intentionally drop the in-progress bit so as to avoid
caching data from in-flux memslots, the implementation oftentimes treats
the bit as part of the generation number itself, e.g. incrementing the
generation increments twice, once to set the flag and once to clear it.
Prior to commit 4bd518f159 ("KVM: use separate generations for
each address space"), incorporating the "update in-progress" bit into
the generation number largely made sense, e.g. "real" generations are
even, "bogus" generations are odd, most code doesn't need to be aware of
the bit, etc...
Now that unique memslots generation numbers are assigned to each address
space, stealthing the in-progress status into the generation number
results in a wide variety of subtle code, e.g. kvm_create_vm() jumps
over bit 0 when initializing the memslots generation without any hint as
to why.
Explicitly define the flag and convert as much code as possible (which
isn't much) to actually treat it like a flag. This paves the way for
eventually using a different bit for "update in-progress" so that it can
be a flag in truth instead of a awkward extension to the generation
number.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
kvm_arch_memslots_updated() is at this point in time an x86-specific
hook for handling MMIO generation wraparound. x86 stashes 19 bits of
the memslots generation number in its MMIO sptes in order to avoid
full page fault walks for repeat faults on emulated MMIO addresses.
Because only 19 bits are used, wrapping the MMIO generation number is
possible, if unlikely. kvm_arch_memslots_updated() alerts x86 that
the generation has changed so that it can invalidate all MMIO sptes in
case the effective MMIO generation has wrapped so as to avoid using a
stale spte, e.g. a (very) old spte that was created with generation==0.
Given that the purpose of kvm_arch_memslots_updated() is to prevent
consuming stale entries, it needs to be called before the new generation
is propagated to memslots. Invalidating the MMIO sptes after updating
memslots means that there is a window where a vCPU could dereference
the new memslots generation, e.g. 0, and incorrectly reuse an old MMIO
spte that was created with (pre-wrap) generation==0.
Fixes: e59dbe09f8 ("KVM: Introduce kvm_arch_memslots_updated()")
Cc: <stable@vger.kernel.org>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Since the offset is added directly to the hva from the
gfn_to_hva_cache, a negative offset could result in an out of bounds
write. The existing BUG_ON only checks for addresses beyond the end of
the gfn_to_hva_cache, not for addresses before the start of the
gfn_to_hva_cache.
Note that all current call sites have non-negative offsets.
Fixes: 4ec6e86362 ("kvm: Introduce kvm_write_guest_offset_cached()")
Reported-by: Cfir Cohen <cfir@google.com>
Signed-off-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Cfir Cohen <cfir@google.com>
Reviewed-by: Peter Shier <pshier@google.com>
Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
There are two problems with KVM_GET_DIRTY_LOG. First, and less important,
it can take kvm->mmu_lock for an extended period of time. Second, its user
can actually see many false positives in some cases. The latter is due
to a benign race like this:
1. KVM_GET_DIRTY_LOG returns a set of dirty pages and write protects
them.
2. The guest modifies the pages, causing them to be marked ditry.
3. Userspace actually copies the pages.
4. KVM_GET_DIRTY_LOG returns those pages as dirty again, even though
they were not written to since (3).
This is especially a problem for large guests, where the time between
(1) and (3) can be substantial. This patch introduces a new
capability which, when enabled, makes KVM_GET_DIRTY_LOG not
write-protect the pages it returns. Instead, userspace has to
explicitly clear the dirty log bits just before using the content
of the page. The new KVM_CLEAR_DIRTY_LOG ioctl can also operate on a
64-page granularity rather than requiring to sync a full memslot;
this way, the mmu_lock is taken for small amounts of time, and
only a small amount of time will pass between write protection
of pages and the sending of their content.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
When manual dirty log reprotect will be enabled, kvm_get_dirty_log_protect's
pointer argument will always be false on exit, because no TLB flush is needed
until the manual re-protection operation. Rename it from "is_dirty" to "flush",
which more accurately tells the caller what they have to do with it.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The functions
kvm_load_guest_fpu()
kvm_put_guest_fpu()
are only used locally, make them static. This requires also that both
functions are moved because they are used before their implementation.
Those functions were exported (via EXPORT_SYMBOL) before commit
e5bb40251a ("KVM: Drop kvm_{load,put}_guest_fpu() exports").
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
There are several blockable mmu notifiers which might sleep in
mmu_notifier_invalidate_range_start and that is a problem for the
oom_reaper because it needs to guarantee a forward progress so it cannot
depend on any sleepable locks.
Currently we simply back off and mark an oom victim with blockable mmu
notifiers as done after a short sleep. That can result in selecting a new
oom victim prematurely because the previous one still hasn't torn its
memory down yet.
We can do much better though. Even if mmu notifiers use sleepable locks
there is no reason to automatically assume those locks are held. Moreover
majority of notifiers only care about a portion of the address space and
there is absolutely zero reason to fail when we are unmapping an unrelated
range. Many notifiers do really block and wait for HW which is harder to
handle and we have to bail out though.
This patch handles the low hanging fruit.
__mmu_notifier_invalidate_range_start gets a blockable flag and callbacks
are not allowed to sleep if the flag is set to false. This is achieved by
using trylock instead of the sleepable lock for most callbacks and
continue as long as we do not block down the call chain.
I think we can improve that even further because there is a common pattern
to do a range lookup first and then do something about that. The first
part can be done without a sleeping lock in most cases AFAICS.
The oom_reaper end then simply retries if there is at least one notifier
which couldn't make any progress in !blockable mode. A retry loop is
already implemented to wait for the mmap_sem and this is basically the
same thing.
The simplest way for driver developers to test this code path is to wrap
userspace code which uses these notifiers into a memcg and set the hard
limit to hit the oom. This can be done e.g. after the test faults in all
the mmu notifier managed memory and set the hard limit to something really
small. Then we are looking for a proper process tear down.
[akpm@linux-foundation.org: coding style fixes]
[akpm@linux-foundation.org: minor code simplification]
Link: http://lkml.kernel.org/r/20180716115058.5559-1-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Christian König <christian.koenig@amd.com> # AMD notifiers
Acked-by: Leon Romanovsky <leonro@mellanox.com> # mlx and umem_odp
Reported-by: David Rientjes <rientjes@google.com>
Cc: "David (ChunMing) Zhou" <David1.Zhou@amd.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Doug Ledford <dledford@redhat.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Mike Marciniszyn <mike.marciniszyn@intel.com>
Cc: Dennis Dalessandro <dennis.dalessandro@intel.com>
Cc: Sudeep Dutt <sudeep.dutt@intel.com>
Cc: Ashutosh Dixit <ashutosh.dixit@intel.com>
Cc: Dimitri Sivanich <sivanich@sgi.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: "Jérôme Glisse" <jglisse@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Felix Kuehling <felix.kuehling@amd.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch is to provide a way for platforms to register hv tlb remote
flush callback and this helps to optimize operation of tlb flush
among vcpus for nested virtualization case.
Signed-off-by: Lan Tianyu <Tianyu.Lan@microsoft.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Switch 'requests' to be explicitly 64-bit and update BUILD_BUG_ON check to
use the size of "requests" instead of the hard-coded '32'.
That gives us a bit more room again for arch-specific requests as we
already ran out of space for x86 due to the hard-coded check.
The only exception here is ARM32 as it is still 32-bits.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim KrÄmář <rkrcmar@redhat.com>
Cc: kvm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Jim Mattson <jmattson@google.com>
Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Introduce a utility function that will be used later on for storage
attributes migration, and use it in kvm_main.c to replace existing code
that does the same thing.
Signed-off-by: Claudio Imbrenda <imbrenda@linux.vnet.ibm.com>
Message-Id: <1525106005-13931-2-git-send-email-imbrenda@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
The kvm struct has been bloating. For example, it's tens of kilo-bytes
for x86, which turns out to be a large amount of memory to allocate
contiguously via kzalloc. Thus, this patch does the following:
1. Uses architecture-specific routines to allocate the kvm struct via
vzalloc for x86.
2. Switches arm to __KVM_HAVE_ARCH_VM_ALLOC so that it can use vzalloc
when has_vhe() is true.
Other architectures continue to default to kalloc, as they have a
dependency on kalloc or have a small-enough struct kvm.
Signed-off-by: Marc Orr <marcorr@google.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Use new return type vm_fault_t for fault handler. For
now, this is just documenting that the function returns
a VM_FAULT value rather than an errno. Once all instances
are converted, vm_fault_t will become a distinct type.
commit 1c8f422059 ("mm: change return type to vm_fault_t")
Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Reviewed-by: Matthew Wilcox <mawilcox@microsoft.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
- Lazy context-switching of FPSIMD registers on arm64
- Allow virtual redistributors to be part of two or more MMIO ranges
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Merge tag 'kvmarm-for-v4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD
KVM/ARM updates for 4.18
- Lazy context-switching of FPSIMD registers on arm64
- Allow virtual redistributors to be part of two or more MMIO ranges
Hyper-V style PV TLB flush hypercalls inmplementation will use this API.
To avoid memory allocation in CONFIG_CPUMASK_OFFSTACK case add
cpumask_var_t argument.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
KVM/ARM differs from other architectures in having to maintain an
additional virtual address space from that of the host and the
guest, because we split the execution of KVM across both EL1 and
EL2.
This results in a need to explicitly map data structures into EL2
(hyp) which are accessed from the hyp code. As we are about to be
more clever with our FPSIMD handling on arm64, which stores data in
the task struct and uses thread_info flags, we will have to map
parts of the currently executing task struct into the EL2 virtual
address space.
However, we don't want to do this on every KVM_RUN, because it is a
fairly expensive operation to walk the page tables, and the common
execution mode is to map a single thread to a VCPU. By introducing
a hook that architectures can select with
HAVE_KVM_VCPU_RUN_PID_CHANGE, we do not introduce overhead for
other architectures, but have a simple way to only map the data we
need when required for arm64.
This patch introduces the framework only, and wires it up in the
arm/arm64 KVM common code.
No functional change.
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Our virtual machines make use of device assignment by configuring
12 NVMe disks for high I/O performance. Each NVMe device has 129
MSI-X Table entries:
Capabilities: [50] MSI-X: Enable+ Count=129 Masked-Vector table: BAR=0 offset=00002000
The windows virtual machines fail to boot since they will map the number of
MSI-table entries that the NVMe hardware reported to the bus to msi routing
table, this will exceed the 1024. This patch extends MAX_IRQ_ROUTES to 4096
for all archs, in the future this might be extended again if needed.
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim KrÄmář <rkrcmar@redhat.com>
Cc: Cornelia Huck <cohuck@redhat.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Signed-off-by: Tonny Lu <tonnylu@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Fix the following sparse warning by moving the prototype
of kvm_arch_mmu_notifier_invalidate_range() to linux/kvm_host.h .
CHECK arch/s390/kvm/../../../virt/kvm/kvm_main.c
arch/s390/kvm/../../../virt/kvm/kvm_main.c:138:13: warning: symbol 'kvm_arch_mmu_notifier_invalidate_range' was not declared. Should it be static?
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Move the kvm_arch_irq_routing_update() prototype outside of
ifdef CONFIG_HAVE_KVM_EVENTFD guards to fix the following sparse warning:
arch/s390/kvm/../../../virt/kvm/irqchip.c:171:28: warning: symbol 'kvm_arch_irq_routing_update' was not declared. Should it be static?
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
After the vcpu_load/vcpu_put pushdown, the handling of asynchronous VCPU
ioctl is already much clearer in that it is obvious that they bypass
vcpu_load and vcpu_put.
However, it is still not perfect in that the different state of the VCPU
mutex is still hidden in the caller. Separate those ioctls into a new
function kvm_arch_vcpu_async_ioctl that returns -ENOIOCTLCMD for more
"traditional" synchronous ioctls.
Cc: James Hogan <jhogan@kernel.org>
Cc: Paul Mackerras <paulus@ozlabs.org>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Suggested-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
As we're about to call vcpu_load() from architecture-specific
implementations of the KVM vcpu ioctls, but yet we access data
structures protected by the vcpu->mutex in the generic code, factor
this logic out from vcpu_load().
x86 is the only architecture which calls vcpu_load() outside of the main
vcpu ioctl function, and these calls will no longer take the vcpu mutex
following this patch. However, with the exception of
kvm_arch_vcpu_postcreate (see below), the callers are either in the
creation or destruction path of the VCPU, which means there cannot be
any concurrent access to the data structure, because the file descriptor
is not yet accessible, or is already gone.
kvm_arch_vcpu_postcreate makes the newly created vcpu potentially
accessible by other in-kernel threads through the kvm->vcpus array, and
we therefore take the vcpu mutex in this case directly.
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Currently, every time a VCPU is scheduled out, the host kernel will
first save the guest FPU/xstate context, then load the qemu userspace
FPU context, only to then immediately save the qemu userspace FPU
context back to memory. When scheduling in a VCPU, the same extraneous
FPU loads and saves are done.
This could be avoided by moving from a model where the guest FPU is
loaded and stored with preemption disabled, to a model where the
qemu userspace FPU is swapped out for the guest FPU context for
the duration of the KVM_RUN ioctl.
This is done under the VCPU mutex, which is also taken when other
tasks inspect the VCPU FPU context, so the code should already be
safe for this change. That should come as no surprise, given that
s390 already has this optimization.
This can fix a bug where KVM calls get_user_pages while owning the
FPU, and the file system ends up requesting the FPU again:
[258270.527947] __warn+0xcb/0xf0
[258270.527948] warn_slowpath_null+0x1d/0x20
[258270.527951] kernel_fpu_disable+0x3f/0x50
[258270.527953] __kernel_fpu_begin+0x49/0x100
[258270.527955] kernel_fpu_begin+0xe/0x10
[258270.527958] crc32c_pcl_intel_update+0x84/0xb0
[258270.527961] crypto_shash_update+0x3f/0x110
[258270.527968] crc32c+0x63/0x8a [libcrc32c]
[258270.527975] dm_bm_checksum+0x1b/0x20 [dm_persistent_data]
[258270.527978] node_prepare_for_write+0x44/0x70 [dm_persistent_data]
[258270.527985] dm_block_manager_write_callback+0x41/0x50 [dm_persistent_data]
[258270.527988] submit_io+0x170/0x1b0 [dm_bufio]
[258270.527992] __write_dirty_buffer+0x89/0x90 [dm_bufio]
[258270.527994] __make_buffer_clean+0x4f/0x80 [dm_bufio]
[258270.527996] __try_evict_buffer+0x42/0x60 [dm_bufio]
[258270.527998] dm_bufio_shrink_scan+0xc0/0x130 [dm_bufio]
[258270.528002] shrink_slab.part.40+0x1f5/0x420
[258270.528004] shrink_node+0x22c/0x320
[258270.528006] do_try_to_free_pages+0xf5/0x330
[258270.528008] try_to_free_pages+0xe9/0x190
[258270.528009] __alloc_pages_slowpath+0x40f/0xba0
[258270.528011] __alloc_pages_nodemask+0x209/0x260
[258270.528014] alloc_pages_vma+0x1f1/0x250
[258270.528017] do_huge_pmd_anonymous_page+0x123/0x660
[258270.528021] handle_mm_fault+0xfd3/0x1330
[258270.528025] __get_user_pages+0x113/0x640
[258270.528027] get_user_pages+0x4f/0x60
[258270.528063] __gfn_to_pfn_memslot+0x120/0x3f0 [kvm]
[258270.528108] try_async_pf+0x66/0x230 [kvm]
[258270.528135] tdp_page_fault+0x130/0x280 [kvm]
[258270.528149] kvm_mmu_page_fault+0x60/0x120 [kvm]
[258270.528158] handle_ept_violation+0x91/0x170 [kvm_intel]
[258270.528162] vmx_handle_exit+0x1ca/0x1400 [kvm_intel]
No performance changes were detected in quick ping-pong tests on
my 4 socket system, which is expected since an FPU+xstate load is
on the order of 0.1us, while ping-ponging between CPUs is on the
order of 20us, and somewhat noisy.
Cc: stable@vger.kernel.org
Signed-off-by: Rik van Riel <riel@redhat.com>
Suggested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[Fixed a bug where reset_vcpu called put_fpu without preceding load_fpu,
which happened inside from KVM_CREATE_VCPU ioctl. - Radim]
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
KVM API says for the signal mask you set via KVM_SET_SIGNAL_MASK, that
"any unblocked signal received [...] will cause KVM_RUN to return with
-EINTR" and that "the signal will only be delivered if not blocked by
the original signal mask".
This, however, is only true, when the calling task has a signal handler
registered for a signal. If not, signal evaluation is short-circuited for
SIG_IGN and SIG_DFL, and the signal is either ignored without KVM_RUN
returning or the whole process is terminated.
Make KVM_SET_SIGNAL_MASK behave as advertised by utilizing logic similar
to that in do_sigtimedwait() to avoid short-circuiting of signals.
Signed-off-by: Jan H. Schönherr <jschoenh@amazon.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
We will not see -ENOMEM (gfn_to_hva() will return KVM_ERR_PTR_BAD_PAGE
for all errors). So we can also get rid of special handling in the
callers of pin_guest_page() and always assume that it is a g2 error.
As also kvm_s390_inject_program_int() should never fail, we can
simplify pin_scb(), too.
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20170901151143.22714-1-david@redhat.com>
Acked-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
If a vcpu exits due to request a user mode spinlock, then
the spinlock-holder may be preempted in user mode or kernel mode.
(Note that not all architectures trap spin loops in user mode,
only AMD x86 and ARM/ARM64 currently do).
But if a vcpu exits in kernel mode, then the holder must be
preempted in kernel mode, so we should choose a vcpu in kernel mode
as a more likely candidate for the lock holder.
This introduces kvm_arch_vcpu_in_kernel() to decide whether the
vcpu is in kernel-mode when it's preempted. kvm_vcpu_on_spin's
new argument says the same of the spinning VCPU.
Signed-off-by: Longpeng(Mike) <longpeng2@huawei.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
nested_get_page() just sounds confusing. All we want is a page from G1.
This is even unrelated to nested.
Let's introduce kvm_vcpu_gpa_to_page() so we don't get too lengthy
lines.
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
[Squash pasto fix from Wanpeng Li. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
During teardown, accesses to memslots and buses are using
rcu_dereference_protected with an always-true condition because
these accesses are done outside the usual mutexes. This
is because the last reference is gone and there cannot be any
concurrent modifications, but rcu_dereference_protected is
ugly and unobvious.
Instead, check the refcount in kvm_get_bus and __kvm_memslots.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Simplify and improve the code so that the PID is always available in
the uevent even when debugfs is not available.
This adds a userspace_pid field to struct kvm, as per Radim's
suggestion, so that the PID can be retrieved on destruction too.
Acked-by: Janosch Frank <frankja@linux.vnet.ibm.com>
Fixes: 286de8f6ac ("KVM: trigger uevents when creating or destroying a VM")
Signed-off-by: Claudio Imbrenda <imbrenda@linux.vnet.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
kvm memslots are protected by srcu and not by rcu. We must use
srcu_dereference_check instead of rcu_dereference_check.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
we access the memslots array via srcu. Mark it as such and
use the right access functions also for the freeing of
memory slots.
Found by sparse:
./include/linux/kvm_host.h:565:16: error: incompatible types in
comparison expression (different address spaces)
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
mark kvm->busses as rcu protected and use the correct access
function everywhere.
found by sparse
virt/kvm/kvm_main.c:3490:15: error: incompatible types in comparison expression (different address spaces)
virt/kvm/kvm_main.c:3509:15: error: incompatible types in comparison expression (different address spaces)
virt/kvm/kvm_main.c:3561:15: error: incompatible types in comparison expression (different address spaces)
virt/kvm/kvm_main.c:3644:15: error: incompatible types in comparison expression (different address spaces)
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
We do use rcu to protect the pid pointer. Mark it as such and
adopt all code to use the proper access methods.
This was detected by sparse.
"virt/kvm/kvm_main.c:2248:15: error: incompatible types in comparison
expression (different address spaces)"
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
A first step in vcpu->requests encapsulation. Additionally, we now
use READ_ONCE() when accessing vcpu->requests, which ensures we
always load vcpu->requests when it's accessed. This is important as
other threads can change it any time. Also, READ_ONCE() documents
that vcpu->requests is used with other threads, likely requiring
memory barriers, which it does.
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
[ Documented the new use of READ_ONCE() and converted another check
in arch/mips/kvm/vz.c ]
Signed-off-by: Andrew Jones <drjones@redhat.com>
Acked-by: Christoffer Dall <cdall@linaro.org>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
Marc Zyngier suggested that we define the arch specific VCPU request
base, rather than requiring each arch to remember to start from 8.
That suggestion, along with Radim Krcmar's recent VCPU request flag
addition, snowballed into defining something of an arch VCPU request
defining API.
No functional change.
(Looks like x86 is running out of arch VCPU request bits. Maybe
someday we'll need to extend to 64.)
Signed-off-by: Andrew Jones <drjones@redhat.com>
Acked-by: Christoffer Dall <cdall@linaro.org>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
* ARM: bugfixes; moved shared 32-bit/64-bit files to virt/kvm/arm;
support for saving/restoring virtual ITS state to userspace
* PPC: XIVE (eXternal Interrupt Virtualization Engine) support
* x86: nVMX improvements, including emulated page modification logging
(PML) which brings nice performance improvements on some workloads
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull more KVM updates from Paolo Bonzini:
"ARM:
- bugfixes
- moved shared 32-bit/64-bit files to virt/kvm/arm
- support for saving/restoring virtual ITS state to userspace
PPC:
- XIVE (eXternal Interrupt Virtualization Engine) support
x86:
- nVMX improvements, including emulated page modification logging
(PML) which brings nice performance improvements on some workloads"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (45 commits)
KVM: arm/arm64: vgic-its: Cleanup after failed ITT restore
KVM: arm/arm64: Don't call map_resources when restoring ITS tables
KVM: arm/arm64: Register ITS iodev when setting base address
KVM: arm/arm64: Get rid of its->initialized field
KVM: arm/arm64: Register iodevs when setting redist base and creating VCPUs
KVM: arm/arm64: Slightly rework kvm_vgic_addr
KVM: arm/arm64: Make vgic_v3_check_base more broadly usable
KVM: arm/arm64: Refactor vgic_register_redist_iodevs
KVM: Add kvm_vcpu_get_idx to get vcpu index in kvm->vcpus
nVMX: Advertise PML to L1 hypervisor
nVMX: Implement emulated Page Modification Logging
kvm: x86: Add a hook for arch specific dirty logging emulation
kvm: nVMX: Validate CR3 target count on nested VM-entry
KVM: set no_llseek in stat_fops_per_vm
KVM: arm/arm64: vgic: Rename kvm_vgic_vcpu_init to kvm_vgic_vcpu_enable
KVM: arm/arm64: Clarification and relaxation to ITS save/restore ABI
KVM: arm64: vgic-v3: KVM_DEV_ARM_VGIC_SAVE_PENDING_TABLES
KVM: arm64: vgic-its: Fix pending table sync
KVM: arm64: vgic-its: ITT save and restore
KVM: arm64: vgic-its: Device table save/restore
...
Pull RCU updates from Ingo Molnar:
"The main changes are:
- Debloat RCU headers
- Parallelize SRCU callback handling (plus overlapping patches)
- Improve the performance of Tree SRCU on a CPU-hotplug stress test
- Documentation updates
- Miscellaneous fixes"
* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (74 commits)
rcu: Open-code the rcu_cblist_n_lazy_cbs() function
rcu: Open-code the rcu_cblist_n_cbs() function
rcu: Open-code the rcu_cblist_empty() function
rcu: Separately compile large rcu_segcblist functions
srcu: Debloat the <linux/rcu_segcblist.h> header
srcu: Adjust default auto-expediting holdoff
srcu: Specify auto-expedite holdoff time
srcu: Expedite first synchronize_srcu() when idle
srcu: Expedited grace periods with reduced memory contention
srcu: Make rcutorture writer stalls print SRCU GP state
srcu: Exact tracking of srcu_data structures containing callbacks
srcu: Make SRCU be built by default
srcu: Fix Kconfig botch when SRCU not selected
rcu: Make non-preemptive schedule be Tasks RCU quiescent state
srcu: Expedite srcu_schedule_cbs_snp() callback invocation
srcu: Parallelize callback handling
kvm: Move srcu_struct fields to end of struct kvm
rcu: Fix typo in PER_RCU_NODE_PERIOD header comment
rcu: Use true/false in assignment to bool
rcu: Use bool value directly
...
Changes include:
- A fix related to the 32-bit idmap stub
- A fix to the bitmask used to deode the operands of an AArch32 CP
instruction
- We have moved the files shared between arch/arm/kvm and
arch/arm64/kvm to virt/kvm/arm
- We add support for saving/restoring the virtual ITS state to
userspace
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Merge tag 'kvm-arm-for-v4.12-round2' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD
Second round of KVM/ARM Changes for v4.12.
Changes include:
- A fix related to the 32-bit idmap stub
- A fix to the bitmask used to deode the operands of an AArch32 CP
instruction
- We have moved the files shared between arch/arm/kvm and
arch/arm64/kvm to virt/kvm/arm
- We add support for saving/restoring the virtual ITS state to
userspace
There are occasional needs to use the index of vcpu in the kvm->vcpus
array to map something related to a VCPU. For example, unlike the
vcpu->vcpu_id, the vcpu index is guaranteed to not be sparse across all
vcpus which is useful when allocating a memory area for each vcpu.
Signed-off-by: Christoffer Dall <cdall@linaro.org>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
The main thing here is a new implementation of the in-kernel
XICS interrupt controller emulation for POWER9 machines, from Ben
Herrenschmidt.
POWER9 has a new interrupt controller called XIVE (eXternal Interrupt
Virtualization Engine) which is able to deliver interrupts directly
to guest virtual CPUs in hardware without hypervisor intervention.
With this new code, the guest still sees the old XICS interface but
performance is better because the XICS emulation in the host uses the
XIVE directly rather than going through a XICS emulation in firmware.
Conflicts:
arch/powerpc/kernel/cpu_setup_power.S [cherry-picked fix]
arch/powerpc/kvm/book3s_xive.c [include asm/debugfs.h]
Merge more updates from Andrew Morton:
- the rest of MM
- various misc things
- procfs updates
- lib/ updates
- checkpatch updates
- kdump/kexec updates
- add kvmalloc helpers, use them
- time helper updates for Y2038 issues. We're almost ready to remove
current_fs_time() but that awaits a btrfs merge.
- add tracepoints to DAX
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (114 commits)
drivers/staging/ccree/ssi_hash.c: fix build with gcc-4.4.4
selftests/vm: add a test for virtual address range mapping
dax: add tracepoint to dax_insert_mapping()
dax: add tracepoint to dax_writeback_one()
dax: add tracepoints to dax_writeback_mapping_range()
dax: add tracepoints to dax_load_hole()
dax: add tracepoints to dax_pfn_mkwrite()
dax: add tracepoints to dax_iomap_pte_fault()
mtd: nand: nandsim: convert to memalloc_noreclaim_*()
treewide: convert PF_MEMALLOC manipulations to new helpers
mm: introduce memalloc_noreclaim_{save,restore}
mm: prevent potential recursive reclaim due to clearing PF_MEMALLOC
mm/huge_memory.c: deposit a pgtable for DAX PMD faults when required
mm/huge_memory.c: use zap_deposited_table() more
time: delete CURRENT_TIME_SEC and CURRENT_TIME
gfs2: replace CURRENT_TIME with current_time
apparmorfs: replace CURRENT_TIME with current_time()
lustre: replace CURRENT_TIME macro
fs: ubifs: replace CURRENT_TIME_SEC with current_time
fs: ufs: use ktime_get_real_ts64() for birthtime
...
Patch series "kvmalloc", v5.
There are many open coded kmalloc with vmalloc fallback instances in the
tree. Most of them are not careful enough or simply do not care about
the underlying semantic of the kmalloc/page allocator which means that
a) some vmalloc fallbacks are basically unreachable because the kmalloc
part will keep retrying until it succeeds b) the page allocator can
invoke a really disruptive steps like the OOM killer to move forward
which doesn't sound appropriate when we consider that the vmalloc
fallback is available.
As it can be seen implementing kvmalloc requires quite an intimate
knowledge if the page allocator and the memory reclaim internals which
strongly suggests that a helper should be implemented in the memory
subsystem proper.
Most callers, I could find, have been converted to use the helper
instead. This is patch 6. There are some more relying on __GFP_REPEAT
in the networking stack which I have converted as well and Eric Dumazet
was not opposed [2] to convert them as well.
[1] http://lkml.kernel.org/r/20170130094940.13546-1-mhocko@kernel.org
[2] http://lkml.kernel.org/r/1485273626.16328.301.camel@edumazet-glaptop3.roam.corp.google.com
This patch (of 9):
Using kmalloc with the vmalloc fallback for larger allocations is a
common pattern in the kernel code. Yet we do not have any common helper
for that and so users have invented their own helpers. Some of them are
really creative when doing so. Let's just add kv[mz]alloc and make sure
it is implemented properly. This implementation makes sure to not make
a large memory pressure for > PAGE_SZE requests (__GFP_NORETRY) and also
to not warn about allocation failures. This also rules out the OOM
killer as the vmalloc is a more approapriate fallback than a disruptive
user visible action.
This patch also changes some existing users and removes helpers which
are specific for them. In some cases this is not possible (e.g.
ext4_kvmalloc, libcfs_kvzalloc) because those seems to be broken and
require GFP_NO{FS,IO} context which is not vmalloc compatible in general
(note that the page table allocation is GFP_KERNEL). Those need to be
fixed separately.
While we are at it, document that __vmalloc{_node} about unsupported gfp
mask because there seems to be a lot of confusion out there.
kvmalloc_node will warn about GFP_KERNEL incompatible (which are not
superset) flags to catch new abusers. Existing ones would have to die
slowly.
[sfr@canb.auug.org.au: f2fs fixup]
Link: http://lkml.kernel.org/r/20170320163735.332e64b7@canb.auug.org.au
Link: http://lkml.kernel.org/r/20170306103032.2540-2-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reviewed-by: Andreas Dilger <adilger@dilger.ca> [ext4 part]
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This reverts commit bbd6411513.
I've been sitting on this revert for too long and it unfortunately
missed 4.11. It's also the reason why I haven't merged ring-based
dirty tracking for 4.12.
Using kvm_vcpu_memslots in kvm_gfn_to_hva_cache_init and
kvm_vcpu_write_guest_offset_cached means that the MSR value can
now be used to access SMRAM, simply by making it point to an SMRAM
physical address. This is problematic because it lets the guest
OS overwrite memory that it shouldn't be able to touch.
Cc: stable@vger.kernel.org
Fixes: bbd6411513
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
We needed the lock to avoid racing with creation of the irqchip on x86. As
kvm_set_irq_routing() calls srcu_synchronize_expedited(), this lock
might be held for a longer time.
Let's introduce an arch specific callback to check if we can actually
add irq routes. For x86, all we have to do is check if we have an
irqchip in the kernel. We don't need kvm->lock at that point as the
irqchip is marked as inititalized only when actually fully created.
Reported-by: Steve Rutherford <srutherford@google.com>
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Fixes: 1df6ddede1 ("KVM: x86: race between KVM_SET_GSI_ROUTING and KVM_CREATE_IRQCHIP")
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This merges in the powerpc topic/xive branch to bring in the code for
the in-kernel XICS interrupt controller emulation to use the new XIVE
(eXternal Interrupt Virtualization Engine) hardware in the POWER9 chip
directly, rather than via a XICS emulation in firmware.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
kvm_make_all_requests() provides a synchronization that waits until all
kicked VCPUs have acknowledged the kick. This is important for
KVM_REQ_MMU_RELOAD as it prevents freeing while lockless paging is
underway.
This patch adds the synchronization property into all requests that are
currently being used with kvm_make_all_requests() in order to preserve
the current behavior and only introduce a new framework. Removing it
from requests where it is not necessary is left for future patches.
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
No need to kick a VCPU that we have just woken up.
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
kvm_vcpu_kick() must issue a general memory barrier prior to reading
vcpu->mode in order to ensure correctness of the mutual-exclusion
memory barrier pattern used with vcpu->requests. While the cmpxchg
called from kvm_vcpu_kick():
kvm_vcpu_kick
kvm_arch_vcpu_should_kick
kvm_vcpu_exiting_guest_mode
cmpxchg
implies general memory barriers before and after the operation, that
implication is only valid when cmpxchg succeeds. We need an explicit
barrier for when it fails, otherwise a VCPU thread on its entry path
that reads zero for vcpu->requests does not exclude the possibility
the requesting thread sees !IN_GUEST_MODE when it reads vcpu->mode.
kvm_make_all_cpus_request already had a barrier, so we remove it, as
now it would be redundant.
Signed-off-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Some operations must ensure that the guest is not running with stale
data, but if the guest is halted, then the update can wait until another
event happens. kvm_make_all_requests() currently doesn't wake up, so we
can mark all requests used with it.
First 8 bits were arbitrarily reserved for request numbers.
Most uses of requests have the request type as a constant, so a compiler
will optimize the '&'.
An alternative would be to have an inline function that would return
whether the request needs a wake-up or not, but I like this one better
even though it might produce worse assembly.
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Users were expected to use kvm_check_request() for testing and clearing,
but request have expanded their use since then and some users want to
only test or do a faster clear.
Make sure that requests are not directly accessed with bit operations.
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This patch makes KVM capable of using the XIVE interrupt controller
to provide the standard PAPR "XICS" style hypercalls. It is necessary
for proper operations when the host uses XIVE natively.
This has been lightly tested on an actual system, including PCI
pass-through with a TG3 device.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
[mpe: Cleanup pr_xxx(), unsplit pr_xxx() strings, etc., fix build
failures by adding KVM_XIVE which depends on KVM_XICS and XIVE, and
adding empty stubs for the kvm_xive_xxx() routines, fixup subject,
integrate fixes from Paul for building PR=y HV=n]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Parallelizing SRCU callback handling will increase the size of
srcu_struct, which will move the kvm structure's kvm_arch field out
of reach of powerpc's current assembly code, which will result in the
following sort of build error:
arch/powerpc/kvm/book3s_hv_rmhandlers.S:617: Error: operand out of range (0x000000000000b328 is not between 0xffffffffffff8000 and 0x0000000000007fff)
This commit moves the srcu_struct fields in the kvm structure to follow
the kvm_arch field, which will allow powerpc's assembly code to continue
to be able to reach the kvm_arch field.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reported-by: Michael Ellerman <michaele@au1.ibm.com>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
[ paulmck: Moved this commit to precede SRCU callback parallelization,
and reworded the commit log into future tense, all in the name of
bisectability. ]
Let's rename it into a proper arch specific callback.
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Its value has never changed; we might as well make it part of the ABI instead
of using the return value of KVM_CHECK_EXTENSION(KVM_CAP_COALESCED_MMIO).
Because PPC does not always make MMIO available, the code has to be made
dependent on CONFIG_KVM_MMIO rather than KVM_COALESCED_MMIO_PAGE_OFFSET.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Legacy device assignment has been deprecated since 4.2 (released
1.5 years ago). VFIO is better and everyone should have switched to it.
If they haven't, this should convince them. :)
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
No caller currently checks the return value of
kvm_io_bus_unregister_dev(). This is evil, as all callers silently go on
freeing their device. A stale reference will remain in the io_bus,
getting at least used again, when the iobus gets teared down on
kvm_destroy_vm() - leading to use after free errors.
There is nothing the callers could do, except retrying over and over
again.
So let's simply remove the bus altogether, print an error and make
sure no one can access this broken bus again (returning -ENOMEM on any
attempt to access it).
Fixes: e93f8a0f82 ("KVM: convert io_bus to SRCU")
Cc: stable@vger.kernel.org # 3.4+
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.
Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
The FPU is always active now when running KVM.
Reviewed-by: David Matlack <dmatlack@google.com>
Reviewed-by: Bandan Das <bsd@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Provide versions of struct gfn_to_hva_cache functions that
take vcpu as a parameter instead of struct kvm. The existing functions
are not needed anymore, so delete them. This allows dirty pages to
be logged in the vcpu dirty ring, instead of the global dirty ring,
for ring-based dirty memory tracking.
Signed-off-by: Lei Cao <lei.cao@stratus.com>
Message-Id: <CY1PR08MB19929BD2AC47A291FD680E83F04F0@CY1PR08MB1992.namprd08.prod.outlook.com>
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM_MEMSLOT_INCOHERENT is not used anymore, as we've killed its
only use in the arm/arm64 MMU code. Let's remove the last artifacts.
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
x86: userspace can now hide nested VMX features from guests; nested
VMX can now run Hyper-V in a guest; support for AVX512_4VNNIW and
AVX512_FMAPS in KVM; infrastructure support for virtual Intel GPUs.
PPC: support for KVM guests on POWER9; improved support for interrupt
polling; optimizations and cleanups.
s390: two small optimizations, more stuff is in flight and will be
in 4.11.
ARM: support for the GICv3 ITS on 32bit platforms.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM updates from Paolo Bonzini:
"Small release, the most interesting stuff is x86 nested virt
improvements.
x86:
- userspace can now hide nested VMX features from guests
- nested VMX can now run Hyper-V in a guest
- support for AVX512_4VNNIW and AVX512_FMAPS in KVM
- infrastructure support for virtual Intel GPUs.
PPC:
- support for KVM guests on POWER9
- improved support for interrupt polling
- optimizations and cleanups.
s390:
- two small optimizations, more stuff is in flight and will be in
4.11.
ARM:
- support for the GICv3 ITS on 32bit platforms"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (94 commits)
arm64: KVM: pmu: Reset PMSELR_EL0.SEL to a sane value before entering the guest
KVM: arm/arm64: timer: Check for properly initialized timer on init
KVM: arm/arm64: vgic-v2: Limit ITARGETSR bits to number of VCPUs
KVM: x86: Handle the kthread worker using the new API
KVM: nVMX: invvpid handling improvements
KVM: nVMX: check host CR3 on vmentry and vmexit
KVM: nVMX: introduce nested_vmx_load_cr3 and call it on vmentry
KVM: nVMX: propagate errors from prepare_vmcs02
KVM: nVMX: fix CR3 load if L2 uses PAE paging and EPT
KVM: nVMX: load GUEST_EFER after GUEST_CR0 during emulated VM-entry
KVM: nVMX: generate MSR_IA32_CR{0,4}_FIXED1 from guest CPUID
KVM: nVMX: fix checks on CR{0,4} during virtual VMX operation
KVM: nVMX: support restore of VMX capability MSRs
KVM: nVMX: generate non-true VMX MSRs based on true versions
KVM: x86: Do not clear RFLAGS.TF when a singlestep trap occurs.
KVM: x86: Add kvm_skip_emulated_instruction and use it.
KVM: VMX: Move skip_emulated_instruction out of nested_vmx_check_vmcs12
KVM: VMX: Reorder some skip_emulated_instruction calls
KVM: x86: Add a return value to kvm_emulate_cpuid
KVM: PPC: Book3S: Move prototypes for KVM functions into kvm_ppc.h
...
Pull x86 FPU updates from Ingo Molnar:
"The main changes in this cycle were:
- do a large round of simplifications after all CPUs do 'eager' FPU
context switching in v4.9: remove CR0 twiddling, remove leftover
eager/lazy bts, etc (Andy Lutomirski)
- more FPU code simplifications: remove struct fpu::counter, clarify
nomenclature, remove unnecessary arguments/functions and better
structure the code (Rik van Riel)"
* 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/fpu: Remove clts()
x86/fpu: Remove stts()
x86/fpu: Handle #NM without FPU emulation as an error
x86/fpu, lguest: Remove CR0.TS support
x86/fpu, kvm: Remove host CR0.TS manipulation
x86/fpu: Remove irq_ts_save() and irq_ts_restore()
x86/fpu: Stop saving and restoring CR0.TS in fpu__init_check_bugs()
x86/fpu: Get rid of two redundant clts() calls
x86/fpu: Finish excising 'eagerfpu'
x86/fpu: Split old_fpu & new_fpu handling into separate functions
x86/fpu: Remove 'cpu' argument from __cpu_invalidate_fpregs_state()
x86/fpu: Split old & new FPU code paths
x86/fpu: Remove __fpregs_(de)activate()
x86/fpu: Rename lazy restore functions to "register state valid"
x86/fpu, kvm: Remove KVM vcpu->fpu_counter
x86/fpu: Remove struct fpu::counter
x86/fpu: Remove use_eager_fpu()
x86/fpu: Remove the XFEATURE_MASK_EAGER/LAZY distinction
x86/fpu: Hard-disable lazy FPU mode
x86/crypto, x86/fpu: Remove X86_FEATURE_EAGER_FPU #ifdef from the crc32c code
PPC KVM update for 4.10:
* Support for KVM guests on POWER9 using the hashed page table MMU.
* Updates and improvements to the halt-polling support on PPC, from
Suraj Jitindar Singh.
* An optimization to speed up emulated MMIO, from Yongji Xie.
* Various other minor cleanups.
The kvm module has the parameters halt_poll_ns, halt_poll_ns_grow, and
halt_poll_ns_shrink. Halt polling was recently added to the powerpc kvm-hv
module and these parameters were essentially duplicated for that. There is
no benefit to this duplication and it can lead to confusion when trying to
tune halt polling.
Thus move the definition of these variables to kvm_host.h and export them.
This will allow the kvm-hv module to use the same module parameters by
accessing these variables, which will be implemented in the next patch,
meaning that they will no longer be duplicated.
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Change unimplemented msrs messages to use pr_debug.
If CONFIG_DYNAMIC_DEBUG is set, then these messages can be
enabled at run time or else -DDEBUG can be used at compile
time to enable them. These messages will still be printed if
ignore_msrs=1.
Signed-off-by: Bandan Das <bsd@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
With the removal of the lazy FPU code, this field is no longer used.
Get rid of it.
Signed-off-by: Rik van Riel <riel@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: pbonzini@redhat.com
Link: http://lkml.kernel.org/r/1475627678-20788-7-git-send-email-riel@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit adds the ability for archs to export
per-vcpu information via a new per-vcpu dir in
the VM's debugfs directory.
If kvm_arch_has_vcpu_debugfs() returns true, then KVM
will create a vcpu dir for each vCPU in the VM's
debugfs directory. Then kvm_arch_create_vcpu_debugfs()
is responsible for populating each vcpu directory
with arch specific entries.
The per-vcpu path in debugfs will look like:
/sys/kernel/debug/kvm/29162-10/vcpu0
/sys/kernel/debug/kvm/29162-10/vcpu1
This is all arch specific for now because the only
user of this interface (x86) wants to export x86-specific
per-vcpu information to user-space.
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Two stubs are added:
o kvm_arch_has_vcpu_debugfs(): must return true if the arch
supports creating debugfs entries in the vcpu debugfs dir
(which will be implemented by the next commit)
o kvm_arch_create_vcpu_debugfs(): code that creates debugfs
entries in the vcpu debugfs dir
For x86, this commit introduces a new file to avoid growing
arch/x86/kvm/x86.c even more.
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM devices were manipulating list data structures without any form of
synchronization, and some implementations of the create operations also
suffered from a lack of synchronization.
Now when we've split the xics create operation into create and init, we
can hold the kvm->lock mutex while calling the create operation and when
manipulating the devices list.
The error path in the generic code gets slightly ugly because we have to
take the mutex again and delete the device from the list, but holding
the mutex during anon_inode_getfd or releasing/locking the mutex in the
common non-error path seemed wrong.
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
As we are about to hold the kvm->lock during the create operation on KVM
devices, we should move the call to xics_debugfs_init into its own
function, since holding a mutex over extended amounts of time might not
be a good idea.
Introduce an init operation on the kvm_device_ops struct which cannot
fail and call this, if configured, after the device has been created.
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Includes GSI routing support to go along with the new VGIC and a small fix that
has been cooking in -next for a while.
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Merge tag 'kvm-arm-for-4.8-take2' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD
KVM/ARM Changes for v4.8 - Take 2
Includes GSI routing support to go along with the new VGIC and a small fix that
has been cooking in -next for a while.
- GICv3 ITS emulation
- Simpler idmap management that fixes potential TLB conflicts
- Honor the kernel protection in HYP mode
- Removal of the old vgic implementation
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Merge tag 'kvm-arm-for-4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into next
KVM/ARM changes for Linux 4.8
- GICv3 ITS emulation
- Simpler idmap management that fixes potential TLB conflicts
- Honor the kernel protection in HYP mode
- Removal of the old vgic implementation
Up to now, only irqchip routing entries could be set. This patch
adds the capability to insert MSI routing entries.
For ARM64, let's also increase KVM_MAX_IRQ_ROUTES to 4096: this
include SPI irqchip routes plus MSI routes. In the future this
might be extended.
Signed-off-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
kvm_setup_default_irq_routing and kvm_setup_empty_irq_routing are
not used by generic code. So let's move the declarations in x86 irq.h
header instead of kvm_host.h.
Signed-off-by: Eric Auger <eric.auger@redhat.com>
Suggested-by: Andre Przywara <andre.przywara@arm.com>
Acked-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Enhance kvm_kernel_irq_routing_entry to transport the device id
field, devid. A new flags field makes possible to indicate the
devid is valid. Those additions are used for ARM GICv3 ITS MSI
injection. The original struct msi_msg msi field is replaced by
a new custom structure that embeds the new fields.
Signed-off-by: Eric Auger <eric.auger@redhat.com>
Suggested-by: Radim Krčmář <rkrcmar@redhat.com>
Acked-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
The kvm_io_bus framework is a nice place of holding information about
various MMIO regions for kernel emulated devices.
Add a call to retrieve the kvm_io_device structure which is associated
with a certain MMIO address. This avoids to duplicate kvm_io_bus'
knowledge of MMIO regions without having to fake MMIO calls if a user
needs the device a certain MMIO address belongs to.
This will be used by the ITS emulation to get the associated ITS device
when someone triggers an MSI via an ioctl from userspace.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Tested-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Use the functions from context_tracking.h directly.
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Make kvm_guest_{enter,exit} and __kvm_guest_{enter,exit} trivial wrappers
around the code in context_tracking.h. Name the context_tracking.h functions
consistently with what those for kernel<->user switch.
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The new created_vcpus field makes it possible to avoid the race between
irqchip and VCPU creation in a much nicer way; just check under kvm->lock
whether a VCPU has already been created.
We can then remove KVM_APIC_ARCHITECTURE too, because at this point the
symbol is only governing the default definition of kvm_vcpu_compatible.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The race between creating the irqchip and the first VCPU is
currently fixed by checking the presence of an irqchip before
updating kvm->online_vcpus, and undoing the whole VCPU creation
if someone created the irqchip in the meanwhile.
Instead, introduce a new field in struct kvm that will count VCPUs
under a mutex, without the atomic access and memory ordering that we
need elsewhere to protect the vcpus array. This also plugs the race
and is more easily applicable in all similar circumstances.
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This patch adds a kvm debugfs subdirectory for each VM, which is named
after its pid and file descriptor. The directories contain the same
kind of files that are already in the kvm debugfs directory, but the
data exported through them is now VM specific.
This makes the debugfs kvm data a convenient alternative to the
tracepoints which already have per VM data. The debugfs data is easy
to read and low overhead.
CC: Dan Carpenter <dan.carpenter@oracle.com> [includes fixes by Dan Carpenter]
Signed-off-by: Janosch Frank <frankja@linux.vnet.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
AVIC has a use for kvm_vcpu_wake_up.
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Tested-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Some wakeups should not be considered a sucessful poll. For example on
s390 I/O interrupts are usually floating, which means that _ALL_ CPUs
would be considered runnable - letting all vCPUs poll all the time for
transactional like workload, even if one vCPU would be enough.
This can result in huge CPU usage for large guests.
This patch lets architectures provide a way to qualify wakeups if they
should be considered a good/bad wakeups in regard to polls.
For s390 the implementation will fence of halt polling for anything but
known good, single vCPU events. The s390 implementation for floating
interrupts does a wakeup for one vCPU, but the interrupt will be delivered
by whatever CPU checks first for a pending interrupt. We prefer the
woken up CPU by marking the poll of this CPU as "good" poll.
This code will also mark several other wakeup reasons like IPI or
expired timers as "good". This will of course also mark some events as
not sucessful. As KVM on z runs always as a 2nd level hypervisor,
we prefer to not poll, unless we are really sure, though.
This patch successfully limits the CPU usage for cases like uperf 1byte
transactional ping pong workload or wakeup heavy workload like OLTP
while still providing a proper speedup.
This also introduced a new vcpu stat "halt_poll_no_tuning" that marks
wakeups that are considered not good for polling.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Radim Krčmář <rkrcmar@redhat.com> (for an earlier version)
Cc: David Matlack <dmatlack@google.com>
Cc: Wanpeng Li <kernellwp@gmail.com>
[Rename config symbol. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
If we don't support a mechanism for bypassing IRQs, don't register as
a consumer. This eliminates meaningless dev_info()s when the connect
fails between producer and consumer, such as on AMD systems where
kvm_x86_ops->update_pi_irte is not implemented
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The KVM_MAX_VCPUS define provides the maximum number of vCPUs per guest, and
also the upper limit for vCPU ids. This is okay for all archs except PowerPC
which can have higher ids, depending on the cpu/core/thread topology. In the
worst case (single threaded guest, host with 8 threads per core), it limits
the maximum number of vCPUS to KVM_MAX_VCPUS / 8.
This patch separates the vCPU numbering from the total number of vCPUs, with
the introduction of KVM_MAX_VCPU_ID, as the maximal valid value for vCPU ids
plus one.
The corresponding KVM_CAP_MAX_VCPU_ID allows userspace to validate vCPU ids
before passing them to KVM_CREATE_VCPU.
This patch only implements KVM_MAX_VCPU_ID with a specific value for PowerPC.
Other archs continue to return KVM_MAX_VCPUS instead.
Suggested-by: Radim Krcmar <rkrcmar@redhat.com>
Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Commit c896939f7c ("KVM: use heuristic for fast VCPU lookup by id") added
a return path that prevents vcpu ids to exceed KVM_MAX_VCPUS. This is a
problem for powerpc where vcpu ids can grow up to 8*KVM_MAX_VCPUS.
This patch simply reverses the logic so that we only try fast path if the
vcpu id can be tried as an index in kvm->vcpus[]. The slow path is not
affected by the change.
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
kvm_make_request and kvm_check_request imply a producer-consumer
relationship; add implicit memory barriers to them. There was indeed
already a place that was adding an explicit smp_mb() to order between
kvm_check_request and the processing of the request. That memory
barrier can be removed (as an added benefit, kvm_check_request can use
smp_mb__after_atomic which is free on x86).
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The problem:
On -rt, an emulated LAPIC timer instances has the following path:
1) hard interrupt
2) ksoftirqd is scheduled
3) ksoftirqd wakes up vcpu thread
4) vcpu thread is scheduled
This extra context switch introduces unnecessary latency in the
LAPIC path for a KVM guest.
The solution:
Allow waking up vcpu thread from hardirq context,
thus avoiding the need for ksoftirqd to be scheduled.
Normal waitqueues make use of spinlocks, which on -RT
are sleepable locks. Therefore, waking up a waitqueue
waiter involves locking a sleeping lock, which
is not allowed from hard interrupt context.
cyclictest command line:
This patch reduces the average latency in my tests from 14us to 11us.
Daniel writes:
Paolo asked for numbers from kvm-unit-tests/tscdeadline_latency
benchmark on mainline. The test was run 1000 times on
tip/sched/core 4.4.0-rc8-01134-g0905f04:
./x86-run x86/tscdeadline_latency.flat -cpu host
with idle=poll.
The test seems not to deliver really stable numbers though most of
them are smaller. Paolo write:
"Anything above ~10000 cycles means that the host went to C1 or
lower---the number means more or less nothing in that case.
The mean shows an improvement indeed."
Before:
min max mean std
count 1000.000000 1000.000000 1000.000000 1000.000000
mean 5162.596000 2019270.084000 5824.491541 20681.645558
std 75.431231 622607.723969 89.575700 6492.272062
min 4466.000000 23928.000000 5537.926500 585.864966
25% 5163.000000 1613252.750000 5790.132275 16683.745433
50% 5175.000000 2281919.000000 5834.654000 23151.990026
75% 5190.000000 2382865.750000 5861.412950 24148.206168
max 5228.000000 4175158.000000 6254.827300 46481.048691
After
min max mean std
count 1000.000000 1000.00000 1000.000000 1000.000000
mean 5143.511000 2076886.10300 5813.312474 21207.357565
std 77.668322 610413.09583 86.541500 6331.915127
min 4427.000000 25103.00000 5529.756600 559.187707
25% 5148.000000 1691272.75000 5784.889825 17473.518244
50% 5160.000000 2308328.50000 5832.025000 23464.837068
75% 5172.000000 2393037.75000 5853.177675 24223.969976
max 5222.000000 3922458.00000 6186.720500 42520.379830
[Patch was originaly based on the swait implementation found in the -rt
tree. Daniel ported it to mainline's version and gathered the
benchmark numbers for tscdeadline_latency test.]
Signed-off-by: Daniel Wagner <daniel.wagner@bmw-carit.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: linux-rt-users@vger.kernel.org
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/1455871601-27484-4-git-send-email-wagi@monom.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
To date, we have implemented two I/O usage models for persistent memory,
PMEM (a persistent "ram disk") and DAX (mmap persistent memory into
userspace). This series adds a third, DAX-GUP, that allows DAX mappings
to be the target of direct-i/o. It allows userspace to coordinate
DMA/RDMA from/to persistent memory.
The implementation leverages the ZONE_DEVICE mm-zone that went into
4.3-rc1 (also discussed at kernel summit) to flag pages that are owned
and dynamically mapped by a device driver. The pmem driver, after
mapping a persistent memory range into the system memmap via
devm_memremap_pages(), arranges for DAX to distinguish pfn-only versus
page-backed pmem-pfns via flags in the new pfn_t type.
The DAX code, upon seeing a PFN_DEV+PFN_MAP flagged pfn, flags the
resulting pte(s) inserted into the process page tables with a new
_PAGE_DEVMAP flag. Later, when get_user_pages() is walking ptes it keys
off _PAGE_DEVMAP to pin the device hosting the page range active.
Finally, get_page() and put_page() are modified to take references
against the device driver established page mapping.
Finally, this need for "struct page" for persistent memory requires
memory capacity to store the memmap array. Given the memmap array for a
large pool of persistent may exhaust available DRAM introduce a
mechanism to allocate the memmap from persistent memory. The new
"struct vmem_altmap *" parameter to devm_memremap_pages() enables
arch_add_memory() to use reserved pmem capacity rather than the page
allocator.
This patch (of 18):
The core has developed a need for a "pfn_t" type [1]. Move the existing
pfn_t in KVM to kvm_pfn_t [2].
[1]: https://lists.01.org/pipermail/linux-nvdimm/2015-September/002199.html
[2]: https://lists.01.org/pipermail/linux-nvdimm/2015-September/002218.html
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Since the numbers now overlap, it makes sense to enumerate
them in asm/kvm_host.h rather than linux/kvm_host.h. Functions
that refer to architecture-specific requests are also moved
to arch/.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Leave room for 4 more arch-independent requests.
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Suggested-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
[Takuya moved all subsequent constants to fill the void, but that
is useless in view of the following patches. So this change looks
nothing like the original. - Paolo]
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
It looks like this in action:
kvm [5197]: vcpu0, guest rIP: 0xffffffff810187ba unhandled rdmsr: 0xc001102
and helps to pinpoint quickly where in the guest we did the unsupported
thing.
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Per Hyper-V specification (and as required by Hyper-V-aware guests),
SynIC provides 4 per-vCPU timers. Each timer is programmed via a pair
of MSRs, and signals expiration by delivering a special format message
to the configured SynIC message slot and triggering the corresponding
synthetic interrupt.
Note: as implemented by this patch, all periodic timers are "lazy"
(i.e. if the vCPU wasn't scheduled for more than the timer period the
timer events are lost), regardless of the corresponding configuration
MSR. If deemed necessary, the "catch up" mode (the timer period is
shortened until the timer catches up) will be implemented later.
Changes v2:
* Use remainder to calculate periodic timer expiration time
Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com>
Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>
CC: Gleb Natapov <gleb@kernel.org>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: "K. Y. Srinivasan" <kys@microsoft.com>
CC: Haiyang Zhang <haiyangz@microsoft.com>
CC: Vitaly Kuznetsov <vkuznets@redhat.com>
CC: Roman Kagan <rkagan@virtuozzo.com>
CC: Denis V. Lunev <den@openvz.org>
CC: qemu-devel@nongnu.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The SynIC message protocol mandates that the message slot is claimed
by atomically setting message type to something other than HVMSG_NONE.
If another message is to be delivered while the slot is still busy,
message pending flag is asserted to indicate to the guest that the
hypervisor wants to be notified when the slot is released.
To make sure the protocol works regardless of where the message
sources are (kernel or userspace), clear the pending flag on SINT ACK
notification, and let the message sources compete for the slot again.
Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com>
Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>
CC: Gleb Natapov <gleb@kernel.org>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: "K. Y. Srinivasan" <kys@microsoft.com>
CC: Haiyang Zhang <haiyangz@microsoft.com>
CC: Vitaly Kuznetsov <vkuznets@redhat.com>
CC: Roman Kagan <rkagan@virtuozzo.com>
CC: Denis V. Lunev <den@openvz.org>
CC: qemu-devel@nongnu.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM creates debugfs files to export VM statistics to userland. To be
able to remove them on kvm exit it tracks the files' dentries.
Since their parent directory is also tracked and since each parent
direntry knows its children we can easily remove them by using
debugfs_remove_recursive(kvm_debugfs_dir). Therefore we don't
need the extra tracking in the kvm_stats_debugfs_item anymore.
Signed-off-by: Janosch Frank <frankja@linux.vnet.ibm.com>
Reviewed-By: Sascha Silbe <silbe@linux.vnet.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Usually, VCPU ids match the array index. So let's try a fast
lookup first before falling back to the slow iteration.
Suggested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Dominik Dingel <dingel@linux.vnet.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
This patch makes kvm_is_visible_gfn return bool due to this particular
function only using either one or zero as its return value.
No functional change.
Signed-off-by: Yaowei Bai <baiyaowei@cmss.chinamobile.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
A new vcpu exit is introduced to notify the userspace of the
changes in Hyper-V SynIC configuration triggered by guest writing to the
corresponding MSRs.
Changes v4:
* exit into userspace only if guest writes into SynIC MSR's
Changes v3:
* added KVM_EXIT_HYPERV types and structs notes into docs
Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com>
Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Gleb Natapov <gleb@kernel.org>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Roman Kagan <rkagan@virtuozzo.com>
CC: Denis V. Lunev <den@openvz.org>
CC: qemu-devel@nongnu.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
SynIC (synthetic interrupt controller) is a lapic extension,
which is controlled via MSRs and maintains for each vCPU
- 16 synthetic interrupt "lines" (SINT's); each can be configured to
trigger a specific interrupt vector optionally with auto-EOI
semantics
- a message page in the guest memory with 16 256-byte per-SINT message
slots
- an event flag page in the guest memory with 16 2048-bit per-SINT
event flag areas
The host triggers a SINT whenever it delivers a new message to the
corresponding slot or flips an event flag bit in the corresponding area.
The guest informs the host that it can try delivering a message by
explicitly asserting EOI in lapic or writing to End-Of-Message (EOM)
MSR.
The userspace (qemu) triggers interrupts and receives EOM notifications
via irqfd with resampler; for that, a GSI is allocated for each
configured SINT, and irq_routing api is extended to support GSI-SINT
mapping.
Changes v4:
* added activation of SynIC by vcpu KVM_ENABLE_CAP
* added per SynIC active flag
* added deactivation of APICv upon SynIC activation
Changes v3:
* added KVM_CAP_HYPERV_SYNIC and KVM_IRQ_ROUTING_HV_SINT notes into
docs
Changes v2:
* do not use posted interrupts for Hyper-V SynIC AutoEOI vectors
* add Hyper-V SynIC vectors into EOI exit bitmap
* Hyper-V SyniIC SINT msr write logic simplified
Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com>
Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Gleb Natapov <gleb@kernel.org>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Roman Kagan <rkagan@virtuozzo.com>
CC: Denis V. Lunev <den@openvz.org>
CC: qemu-devel@nongnu.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Actually kvm_arch_irq_routing_update() should be
kvm_arch_post_irq_routing_update() as it's called at the end
of irq routing update.
This renaming frees kvm_arch_irq_routing_update function name.
kvm_arch_irq_routing_update() weak function which will be used
to update mappings for arch-specific irq routing entries
(in particular, the upcoming Hyper-V synthetic interrupts).
Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com>
Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Gleb Natapov <gleb@kernel.org>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Roman Kagan <rkagan@virtuozzo.com>
CC: Denis V. Lunev <den@openvz.org>
CC: qemu-devel@nongnu.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Let's provide a function to lookup a VCPU by id.
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Dominik Dingel <dingel@linux.vnet.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
[split patch from refactoring patch]
VMX and SVM calculate the TSC scaling ratio in a similar logic, so this
patch generalizes it to a common TSC scaling function.
Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com>
[Inline the multiplication and shift steps into mul_u64_u64_shr. Remove
BUG_ON. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The function is not used outside device assignment, and
kvm_arch_set_irq_inatomic has a different prototype. Move it here and
make it static to avoid confusion.
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
We do not want to do too much work in atomic context, in particular
not walking all the VCPUs of the virtual machine. So we want
to distinguish the architecture-specific injection function for irqfd
from kvm_set_msi. Since it's still empty, reuse the newly added
kvm_arch_set_irq and rename it to kvm_arch_set_irq_inatomic.
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Includes a number of fixes for the arch-timer, introducing proper
level-triggered semantics for the arch-timers, a series of patches to
synchronously halt a guest (prerequisite for IRQ forwarding), some tracepoint
improvements, a tweak for the EL2 panic handlers, some more VGIC cleanups
getting rid of redundant state, and finally a stylistic change that gets rid of
some ctags warnings.
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Merge tag 'kvm-arm-for-4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD
KVM/ARM Changes for v4.4-rc1
Includes a number of fixes for the arch-timer, introducing proper
level-triggered semantics for the arch-timers, a series of patches to
synchronously halt a guest (prerequisite for IRQ forwarding), some tracepoint
improvements, a tweak for the EL2 panic handlers, some more VGIC cleanups
getting rid of redundant state, and finally a stylistic change that gets rid of
some ctags warnings.
Conflicts:
arch/x86/include/asm/kvm_host.h
Some times it is useful for architecture implementations of KVM to know
when the VCPU thread is about to block or when it comes back from
blocking (arm/arm64 needs to know this to properly implement timers, for
example).
Therefore provide a generic architecture callback function in line with
what we do elsewhere for KVM generic-arch interactions.
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Allow for arch-specific interrupt types to be set. For that, add
kvm_arch_set_irq() which takes interrupt type-specific action if it
recognizes the interrupt type given, and -EWOULDBLOCK otherwise.
The default implementation always returns -EWOULDBLOCK.
Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com>
Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Vitaly Kuznetsov <vkuznets@redhat.com>
CC: "K. Y. Srinivasan" <kys@microsoft.com>
CC: Gleb Natapov <gleb@kernel.org>
CC: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Factor out kvm_notify_acked_gsi() helper to iterate over EOI listeners
and notify those matching the given gsi.
It will be reused in the upcoming Hyper-V SynIC implementation.
Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com>
Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Vitaly Kuznetsov <vkuznets@redhat.com>
CC: "K. Y. Srinivasan" <kys@microsoft.com>
CC: Gleb Natapov <gleb@kernel.org>
CC: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This patch updates the Posted-Interrupts Descriptor when vCPU
is blocked.
pre-block:
- Add the vCPU to the blocked per-CPU list
- Set 'NV' to POSTED_INTR_WAKEUP_VECTOR
post-block:
- Remove the vCPU from the per-CPU list
Signed-off-by: Feng Wu <feng.wu@intel.com>
[Concentrate invocation of pre/post-block hooks to vcpu_block. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This patch adds an arch specific hooks 'arch_update' in
'struct kvm_kernel_irqfd'. On Intel side, it is used to
update the IRTE when VT-d posted-interrupts is used.
Signed-off-by: Feng Wu <feng.wu@intel.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This patch introduces
- kvm_arch_irq_bypass_add_producer
- kvm_arch_irq_bypass_del_producer
- kvm_arch_irq_bypass_stop
- kvm_arch_irq_bypass_start
They make possible to specialize the KVM IRQ bypass consumer in
case CONFIG_KVM_HAVE_IRQ_BYPASS is set.
Signed-off-by: Eric Auger <eric.auger@linaro.org>
[Add weak implementations of the callbacks. - Feng]
Signed-off-by: Feng Wu <feng.wu@intel.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
HV_X64_MSR_RESET msr is used by Hyper-V based Windows guest
to reset guest VM by hypervisor.
Necessary to support loading of winhv.sys in guest, which in turn is
required to support Windows VMBus.
Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com>
Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Gleb Natapov <gleb@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
In order to support a userspace IOAPIC interacting with an in kernel
APIC, the EOI exit bitmaps need to be configurable.
If the IOAPIC is in userspace (i.e. the irqchip has been split), the
EOI exit bitmaps will be set whenever the GSI Routes are configured.
In particular, for the low MSI routes are reservable for userspace
IOAPICs. For these MSI routes, the EOI Exit bit corresponding to the
destination vector of the route will be set for the destination VCPU.
The intention is for the userspace IOAPICs to use the reservable MSI
routes to inject interrupts into the guest.
This is a slight abuse of the notion of an MSI Route, given that MSIs
classically bypass the IOAPIC. It might be worthwhile to add an
additional route type to improve clarity.
Compile tested for Intel x86.
Signed-off-by: Steve Rutherford <srutherford@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Adds KVM_EXIT_IOAPIC_EOI which allows the kernel to EOI
level-triggered IOAPIC interrupts.
Uses a per VCPU exit bitmap to decide whether or not the IOAPIC needs
to be informed (which is identical to the EOI_EXIT_BITMAP field used
by modern x86 processors, but can also be used to elide kvm IOAPIC EOI
exits on older processors).
[Note: A prototype using ResampleFDs found that decoupling the EOI
from the VCPU's thread made it possible for the VCPU to not see a
recent EOI after reentering the guest. This does not match real
hardware.]
Compile tested for Intel x86.
Signed-off-by: Steve Rutherford <srutherford@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
First patch in a series which enables the relocation of the
PIC/IOAPIC to userspace.
Adds capability KVM_CAP_SPLIT_IRQCHIP;
KVM_CAP_SPLIT_IRQCHIP enables the construction of LAPICs without the
rest of the irqchip.
Compile tested for x86.
Signed-off-by: Steve Rutherford <srutherford@google.com>
Suggested-by: Andrew Honig <ahonig@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Change halt_poll_ns into per-VCPU variable, seeded from module parameter,
to allow greater flexibility.
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Sending of notification is done by exiting vcpu to user space
if KVM_REQ_HV_CRASH is enabled for vcpu. At exit to user space
the kvm_run structure contains system_event with type
KVM_SYSTEM_EVENT_CRASH to notify about guest crash occurred.
Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Peter Hornyack <peterhornyack@google.com>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Gleb Natapov <gleb@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
vcpu_debug is useful macro like kvm_debug but additionally
includes vcpu context inside output.
Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Peter Hornyack <peterhornyack@google.com>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Gleb Natapov <gleb@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
If there are no assigned devices, the guest PAT are not providing
any useful information and can be overridden to writeback; VMX
always does this because it has the "IPAT" bit in its extended
page table entries, but SVM does not have anything similar.
Hook into VFIO and legacy device assignment so that they
provide this information to KVM.
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Tested-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Only two ioctls have to be modified; the address space id is
placed in the higher 16 bits of their slot id argument.
As of this patch, no architecture defines more than one
address space; x86 will be the first.
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
We need to hide SMRAM from guests not running in SMM. Therefore, all
uses of kvm_read_guest* and kvm_write_guest* must be changed to use
different address spaces, depending on whether the VCPU is in system
management mode. We need to introduce a new family of functions for
this purpose.
For now, the VCPU-based functions have the same behavior as the
existing per-VM ones, they just accept a different type for the
first argument. Later however they will be changed to use one of many
"struct kvm_memslots" stored in struct kvm, through an architecture hook.
VM-based functions will unconditionally use the first memslots pointer.
Whenever possible, this patch introduces slot-based functions with an
__ prefix, with two wrappers for generic and vcpu-based actions.
The exceptions are kvm_read_guest and kvm_write_guest, which are copied
into the new functions kvm_vcpu_read_guest and kvm_vcpu_write_guest.
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This patch adds the interface between x86.c and the emulator: the
SMBASE register, a new emulator flag, the RSM instruction. It also
adds a new request bit that will be used by the KVM_SMI ioctl.
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The memory slot is already available from gfn_to_memslot_dirty_bitmap.
Isn't it a shame to look it up again? Plus, it makes gfn_to_page_many_atomic
agnostic of multiple VCPU address spaces.
Reviewed-by: Radim Krcmar <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This lets the function access the new memory slot without going through
kvm_memslots and id_to_memslot. It will simplify the code when more
than one address space will be supported.
Unfortunately, the "const"ness of the new argument must be casted
away in two places. Fixing KVM to accept const struct kvm_memory_slot
pointers would require modifications in pretty much all architectures,
and is left for later.
Reviewed-by: Radim Krcmar <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Architecture-specific helpers are not supposed to muck with
struct kvm_userspace_memory_region contents. Add const to
enforce this.
In order to eliminate the only write in __kvm_set_memory_region,
the cleaning of deleted slots is pulled up from update_memslots
to __kvm_set_memory_region.
Reviewed-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Reviewed-by: Radim Krcmar <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
gfn_to_pfn_async is used in just one place, and because of x86-specific
treatment that place will need to look at the memory slot. Hence inline
it into try_async_pf and export __gfn_to_pfn_memslot.
The patch also switches the subsequent call to gfn_to_pfn_prot to use
__gfn_to_pfn_memslot. This is a small optimization. Finally, remove
the now-unused async argument of __gfn_to_pfn.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Currently KVM will clear the FPU bits in CR0.TS in the VMCS, and trap to
re-load them every time the guest accesses the FPU after a switch back into
the guest from the host.
This patch copies the x86 task switch semantics for FPU loading, with the
FPU loaded eagerly after first use if the system uses eager fpu mode,
or if the guest uses the FPU frequently.
In the latter case, after loading the FPU for 255 times, the fpu_counter
will roll over, and we will revert to loading the FPU on demand, until
it has been established that the guest is still actively using the FPU.
This mirrors the x86 task switch policy, which seems to work.
Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Several kvm architectures disable interrupts before kvm_guest_enter.
kvm_guest_enter then uses local_irq_save/restore to disable interrupts
again or for the first time. Lets provide underscore versions of
kvm_guest_{enter|exit} that assume being called locked.
kvm_guest_enter now disables interrupts for the full function and
thus we can remove the check for preemptible.
This patch then adopts s390/kvm to use local_irq_disable/enable calls
which are slighty cheaper that local_irq_save/restore and call these
new functions.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Pull NOHZ changes from Ingo Molnar:
"This tree adds full dynticks support to KVM guests (support the
disabling of the timer tick on the guest). The main missing piece was
the recognition of guest execution as RCU extended quiescent state and
related changes"
* 'timers-nohz-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
kvm,rcu,nohz: use RCU extended quiescent state when running KVM guest
context_tracking: Export context_tracking_user_enter/exit
context_tracking: Run vtime_user_enter/exit only when state == CONTEXT_USER
context_tracking: Add stub context_tracking_is_enabled
context_tracking: Generalize context tracking APIs to support user and guest
context_tracking: Rename context symbols to prepare for transition state
ppc: Remove unused cpp symbols in kvm headers
After reset, the CPU can change the BSP, which will be used upon INIT. Reset
should return the BSP which QEMU asked for, and therefore handled accordingly.
To quote: "If the MP protocol has completed and a BSP is chosen, subsequent
INITs (either to a specific processor or system wide) do not cause the MP
protocol to be repeated."
[Intel SDM 8.4.2: MP Initialization Protocol Requirements and Restrictions]
Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Message-Id: <1427933438-12782-3-git-send-email-namit@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This is needed in e.g. ARM vGIC emulation, where the MMIO handling
depends on the VCPU that does the access.
Signed-off-by: Nikolay Nikolaev <n.nikolaev@virtualopensystems.com>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Introduce __KVM_HAVE_ARCH_INTC_INITIALIZED define and
associated kvm_arch_intc_initialized function. This latter
allows to test whether the virtual interrupt controller is initialized
and ready to accept virtual IRQ injection. On some architectures,
the virtual interrupt controller is dynamically instantiated, justifying
that kind of check.
The new function can now be used by irqfd to check whether the
virtual interrupt controller is ready on KVM_IRQFD request. If not,
KVM_IRQFD returns -EAGAIN.
Signed-off-by: Eric Auger <eric.auger@linaro.org>
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
kvm_kvfree() provides exactly the same functionality as the
new common kvfree() function - so let's simply replace the
kvm function with the common function.
Signed-off-by: Thomas Huth <thuth@linux.vnet.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
The host kernel is not doing anything while the CPU is executing
a KVM guest VCPU, so it can be marked as being in an extended
quiescent state, identical to that used when running user space
code.
The only exception to that rule is when the host handles an
interrupt, which is already handled by the irq code, which
calls rcu_irq_enter and rcu_irq_exit.
The guest_enter and guest_exit functions already switch vtime
accounting independent of context tracking. Leave those calls
where they are, instead of moving them into the context tracking
code.
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Rik van Riel <riel@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Will deacon <will.deacon@arm.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Common: Optional support for adding a small amount of polling on each HLT
instruction executed in the guest (or equivalent for other architectures).
This can improve latency up to 50% on some scenarios (e.g. O_DSYNC writes
or TCP_RR netperf tests). This also has to be enabled manually for now,
but the plan is to auto-tune this in the future.
ARM/ARM64: the highlights are support for GICv3 emulation and dirty page
tracking
s390: several optimizations and bugfixes. Also a first: a feature
exposed by KVM (UUID and long guest name in /proc/sysinfo) before
it is available in IBM's hypervisor! :)
MIPS: Bugfixes.
x86: Support for PML (page modification logging, a new feature in
Broadwell Xeons that speeds up dirty page tracking), nested virtualization
improvements (nested APICv---a nice optimization), usual round of emulation
fixes. There is also a new option to reduce latency of the TSC deadline
timer in the guest; this needs to be tuned manually.
Some commits are common between this pull and Catalin's; I see you
have already included his tree.
ARM has other conflicts where functions are added in the same place
by 3.19-rc and 3.20 patches. These are not large though, and entirely
within KVM.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM update from Paolo Bonzini:
"Fairly small update, but there are some interesting new features.
Common:
Optional support for adding a small amount of polling on each HLT
instruction executed in the guest (or equivalent for other
architectures). This can improve latency up to 50% on some
scenarios (e.g. O_DSYNC writes or TCP_RR netperf tests). This
also has to be enabled manually for now, but the plan is to
auto-tune this in the future.
ARM/ARM64:
The highlights are support for GICv3 emulation and dirty page
tracking
s390:
Several optimizations and bugfixes. Also a first: a feature
exposed by KVM (UUID and long guest name in /proc/sysinfo) before
it is available in IBM's hypervisor! :)
MIPS:
Bugfixes.
x86:
Support for PML (page modification logging, a new feature in
Broadwell Xeons that speeds up dirty page tracking), nested
virtualization improvements (nested APICv---a nice optimization),
usual round of emulation fixes.
There is also a new option to reduce latency of the TSC deadline
timer in the guest; this needs to be tuned manually.
Some commits are common between this pull and Catalin's; I see you
have already included his tree.
Powerpc:
Nothing yet.
The KVM/PPC changes will come in through the PPC maintainers,
because I haven't received them yet and I might end up being
offline for some part of next week"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (130 commits)
KVM: ia64: drop kvm.h from installed user headers
KVM: x86: fix build with !CONFIG_SMP
KVM: x86: emulate: correct page fault error code for NoWrite instructions
KVM: Disable compat ioctl for s390
KVM: s390: add cpu model support
KVM: s390: use facilities and cpu_id per KVM
KVM: s390/CPACF: Choose crypto control block format
s390/kernel: Update /proc/sysinfo file with Extended Name and UUID
KVM: s390: reenable LPP facility
KVM: s390: floating irqs: fix user triggerable endless loop
kvm: add halt_poll_ns module parameter
kvm: remove KVM_MMIO_SIZE
KVM: MIPS: Don't leak FPU/DSP to guest
KVM: MIPS: Disable HTW while in guest
KVM: nVMX: Enable nested posted interrupt processing
KVM: nVMX: Enable nested virtual interrupt delivery
KVM: nVMX: Enable nested apic register virtualization
KVM: nVMX: Make nested control MSRs per-cpu
KVM: nVMX: Enable nested virtualize x2apic mode
KVM: nVMX: Prepare for using hardware MSR bitmap
...
Use the more generic get_user_pages_unlocked which has the additional
benefit of passing FAULT_FLAG_ALLOW_RETRY at the very first page fault
(which allows the first page fault in an unmapped area to be always able
to block indefinitely by being allowed to release the mmap_sem).
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Reviewed-by: Andres Lagar-Cavilla <andreslc@google.com>
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Peter Feiner <pfeiner@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We don't have to write protect guest memory for dirty logging if architecture
supports hardware dirty logging, such as PML on VMX, so rename it to be more
generic.
Signed-off-by: Kai Huang <kai.huang@linux.intel.com>
Reviewed-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
1. Generic
- sparse warning (make function static)
- optimize locking
- bugfixes for interrupt injection
- fix MVPG addressing modes
2. hrtimer/wakeup fun
A recent change can cause KVM hangs if adjtime is used in the host.
The hrtimer might wake up too early or too late. Too early is fatal
as vcpu_block will see that the wakeup condition is not met and
sleep again. This CPU might never wake up again.
This series addresses this problem. adjclock slowing down the host
clock will result in too late wakeups. This will require more work.
In addition to that we also change the hrtimer from REALTIME to
MONOTONIC to avoid similar problems with timedatectl set-time.
3. sigp rework
We will move all "slow" sigps to QEMU (protected with a capability that
can be enabled) to avoid several races between concurrent SIGP orders.
4. Optimize the shadow page table
Provide an interface to announce the maximum guest size. The kernel
will use that to make the pagetable 2,3,4 (or theoretically) 5 levels.
5. Provide an interface to set the guest TOD
We now use two vm attributes instead of two oneregs, as oneregs are
vcpu ioctl and we don't want to call them from other threads.
6. Protected key functions
The real HMC allows to enable/disable protected key CPACF functions.
Lets provide an implementation + an interface for QEMU to activate
this the protected key instructions.
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Merge tag 'kvm-s390-next-20150122' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into kvm-next
KVM: s390: fixes and features for kvm/next (3.20)
1. Generic
- sparse warning (make function static)
- optimize locking
- bugfixes for interrupt injection
- fix MVPG addressing modes
2. hrtimer/wakeup fun
A recent change can cause KVM hangs if adjtime is used in the host.
The hrtimer might wake up too early or too late. Too early is fatal
as vcpu_block will see that the wakeup condition is not met and
sleep again. This CPU might never wake up again.
This series addresses this problem. adjclock slowing down the host
clock will result in too late wakeups. This will require more work.
In addition to that we also change the hrtimer from REALTIME to
MONOTONIC to avoid similar problems with timedatectl set-time.
3. sigp rework
We will move all "slow" sigps to QEMU (protected with a capability that
can be enabled) to avoid several races between concurrent SIGP orders.
4. Optimize the shadow page table
Provide an interface to announce the maximum guest size. The kernel
will use that to make the pagetable 2,3,4 (or theoretically) 5 levels.
5. Provide an interface to set the guest TOD
We now use two vm attributes instead of two oneregs, as oneregs are
vcpu ioctl and we don't want to call them from other threads.
6. Protected key functions
The real HMC allows to enable/disable protected key CPACF functions.
Lets provide an implementation + an interface for QEMU to activate
this the protected key instructions.
The return value of kvm_arch_vcpu_postcreate is not checked in its
caller. This is okay, because only x86 provides vcpu_postcreate right
now and it could only fail if vcpu_load failed. But that is not
possible during KVM_CREATE_VCPU (kvm_arch_vcpu_load is void, too), so
just get rid of the unchecked return value.
Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
With everything separated and prepared, we implement a model of a
GICv3 distributor and redistributors by using the existing framework
to provide handler functions for each register group.
Currently we limit the emulation to a model enforcing a single
security state, with SRE==1 (forcing system register access) and
ARE==1 (allowing more than 8 VCPUs).
We share some of the functions provided for GICv2 emulation, but take
the different ways of addressing (v)CPUs into account.
Save and restore is currently not implemented.
Similar to the split-off of the GICv2 specific code, the new emulation
code goes into a new file (vgic-v3-emul.c).
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Currently we unconditionally register the GICv2 emulation device
during the host's KVM initialization. Since with GICv3 support we
may end up with only v2 or only v3 or both supported, we move the
registration into the GIC probing function, where we will later know
which combination is valid.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
kvm_get_dirty_log() provides generic handling of dirty bitmap, currently reused
by several architectures. Building on that we intrdoduce
kvm_get_dirty_log_protect() adding write protection to mark these pages dirty
for future write access, before next KVM_GET_DIRTY_LOG ioctl call from user
space.
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Mario Smarduch <m.smarduch@samsung.com>
problems, clarifies VCPU init, and fixes a regression concerning the
VGIC init flow.
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Merge tag 'kvm-arm-for-3.19-take2' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD
Second round of changes for KVM for arm/arm64 for v3.19; fixes reboot
problems, clarifies VCPU init, and fixes a regression concerning the
VGIC init flow.
Conflicts:
arch/ia64/kvm/kvm-ia64.c [deleted in HEAD and modified in kvmarm]
Current linear search doesn't scale well when
large amount of memslots is used and looked up slot
is not in the beginning memslots array.
Taking in account that memslots don't overlap, it's
possible to switch sorting order of memslots array from
'npages' to 'base_gfn' and use binary search for
memslot lookup by GFN.
As result of switching to binary search lookup times
are reduced with large amount of memslots.
Following is a table of search_memslot() cycles
during WS2008R2 guest boot.
boot, boot + ~10 min
mostly same of using it,
slot lookup randomized lookup
max average average
cycles cycles cycles
13 slots : 1450 28 30
13 slots : 1400 30 40
binary search
117 slots : 13000 30 460
117 slots : 2000 35 180
binary search
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
In typical guest boot workload only 2-3 memslots are used
extensively, and at that it's mostly the same memslot
lookup operation.
Adding LRU cache improves average lookup time from
46 to 28 cycles (~40%) for this workload.
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Memory regions may be incoherent with the caches, typically when the
guest has mapped a host system RAM backed memory region as uncached.
Add a flag KVM_MEMSLOT_INCOHERENT so that we can tag these memslots
and handle them appropriately when mapping them.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
This reverts commit 85c8555ff0 ("KVM: check for !is_zero_pfn() in
kvm_is_mmio_pfn()") and renames the function to kvm_is_reserved_pfn.
The problem being addressed by the patch above was that some ARM code
based the memory mapping attributes of a pfn on the return value of
kvm_is_mmio_pfn(), whose name indeed suggests that such pfns should
be mapped as device memory.
However, kvm_is_mmio_pfn() doesn't do quite what it says on the tin,
and the existing non-ARM users were already using it in a way which
suggests that its name should probably have been 'kvm_is_reserved_pfn'
from the beginning, e.g., whether or not to call get_page/put_page on
it etc. This means that returning false for the zero page is a mistake
and the patch above should be reverted.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Create a new header, and hide the device assignment functions there.
Move struct kvm_assigned_dev_kernel to assigned-dev.c by modifying
arch/x86/kvm/iommu.c to take a PCI device struct.
Based on a patch by Radim Krcmar <rkrcmark@redhat.com>.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Now that ia64 is gone, we can hide deprecated device assignment in x86.
Notable changes:
- kvm_vm_ioctl_assigned_device() was moved to x86/kvm_arch_vm_ioctl()
The easy parts were removed from generic kvm code, remaining
- kvm_iommu_(un)map_pages() would require new code to be moved
- struct kvm_assigned_dev_kernel depends on struct kvm_irq_ack_notifier
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
ia64 does not need them anymore. Ack notifiers become x86-specific
too.
Suggested-by: Gleb Natapov <gleb@kernel.org>
Reviewed-by: Radim Krcmar <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This includes a bunch of changes:
- Support read-only memory slots on arm/arm64
- Various changes to fix Sparse warnings
- Correctly detect write vs. read Stage-2 faults
- Various VGIC cleanups and fixes
- Dynamic VGIC data strcuture sizing
- Fix SGI set_clear_pend offset bug
- Fix VTTBR_BADDR Mask
- Correctly report the FSC on Stage-2 faults
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Merge tag 'kvm-arm-for-3.18' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into kvm-next
Changes for KVM for arm/arm64 for 3.18
This includes a bunch of changes:
- Support read-only memory slots on arm/arm64
- Various changes to fix Sparse warnings
- Correctly detect write vs. read Stage-2 faults
- Various VGIC cleanups and fixes
- Dynamic VGIC data strcuture sizing
- Fix SGI set_clear_pend offset bug
- Fix VTTBR_BADDR Mask
- Correctly report the FSC on Stage-2 faults
Conflicts:
virt/kvm/eventfd.c
[duplicate, different patch where the kvm-arm version broke x86.
The kvm tree instead has the right one]
Currently, the APIC access page is pinned by KVM for the entire life
of the guest. We want to make it migratable in order to make memory
hot-unplug available for machines that run KVM.
This patch prepares to handle this in generic code, through a new
request bit (that will be set by the MMU notifier) and a new hook
that is called whenever the request bit is processed.
Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Different architectures need different requests, and in fact we
will use this function in architecture-specific code later. This
will be outside kvm_main.c, so make it non-static and rename it to
kvm_make_all_cpus_request().
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
When KVM handles a tdp fault it uses FOLL_NOWAIT. If the guest memory
has been swapped out or is behind a filemap, this will trigger async
readahead and return immediately. The rationale is that KVM will kick
back the guest with an "async page fault" and allow for some other
guest process to take over.
If async PFs are enabled the fault is retried asap from an async
workqueue. If not, it's retried immediately in the same code path. In
either case the retry will not relinquish the mmap semaphore and will
block on the IO. This is a bad thing, as other mmap semaphore users
now stall as a function of swap or filemap latency.
This patch ensures both the regular and async PF path re-enter the
fault allowing for the mmap semaphore to be relinquished in the case
of IO wait.
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Andres Lagar-Cavilla <andreslc@google.com>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Now that we have a dynamic means to register kvm_device_ops, use that
for the VFIO kvm device, instead of relying on the static table.
This is achieved by a module_init call to register the ops with KVM.
Cc: Gleb Natapov <gleb@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Alex Williamson <Alex.Williamson@redhat.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Using the new kvm_register_device_ops() interface makes us get rid of
an #ifdef in common code.
Cc: Gleb Natapov <gleb@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Now that we have a dynamic means to register kvm_device_ops, use that
for the ARM VGIC, instead of relying on the static table.
Cc: Gleb Natapov <gleb@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
kvm_ioctl_create_device currently has knowledge of all the device types
and their associated ops. This is fairly inflexible when adding support
for new in-kernel device emulations, so move what we currently have out
into a table, which can support dynamic registration of ops by new
drivers for virtual hardware.
Cc: Alex Williamson <Alex.Williamson@redhat.com>
Cc: Alex Graf <agraf@suse.de>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
In the beggining was on_each_cpu(), which required an unused argument to
kvm_arch_ops.hardware_{en,dis}able, but this was soon forgotten.
Remove unnecessary arguments that stem from this.
Signed-off-by: Radim KrÄmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Opaque KVM structs are useful for prototypes in asm/kvm_host.h, to avoid
"'struct foo' declared inside parameter list" warnings (and consequent
breakage due to conflicting types).
Move them from individual files to a generic place in linux/kvm_types.h.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
To support read-only memory regions on arm and arm64, we have a need to
resolve a gfn to an hva given a pointer to a memslot to avoid looping
through the memslots twice and to reuse the hva error checking of
gfn_to_hva_prot(), add a new gfn_to_hva_memslot_prot() function and
refactor gfn_to_hva_prot() to use this function.
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Introduce preempt notifiers for architecture specific code.
Advantage over creating a new notifier in every arch is slightly simpler
code and guaranteed call order with respect to kvm_sched_in.
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Commits e4d57e1ee1 (KVM: Move irq notifier implementation into
eventfd.c, 2014-06-30) included the irq notifier code unconditionally
in eventfd.c, while it was under CONFIG_HAVE_KVM_IRQCHIP before.
Similarly, commit 297e21053a (KVM: Give IRQFD its own separate enabling
Kconfig option, 2014-06-30) moved code from CONFIG_HAVE_IRQ_ROUTING
to CONFIG_HAVE_KVM_IRQFD but forgot to move the pieces that used to be
under CONFIG_HAVE_KVM_IRQCHIP.
Together, this broke compilation without CONFIG_KVM_XICS. Fix by adding
or changing the #ifdefs so that they point at CONFIG_HAVE_KVM_IRQFD.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Currently, the IRQFD code is conditional on CONFIG_HAVE_KVM_IRQ_ROUTING.
So that we can have the IRQFD code compiled in without having the
IRQ routing code, this creates a new CONFIG_HAVE_KVM_IRQFD, makes
the IRQFD code conditional on it instead of CONFIG_HAVE_KVM_IRQ_ROUTING,
and makes all the platforms that currently select HAVE_KVM_IRQ_ROUTING
also select HAVE_KVM_IRQFD.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Tested-by: Eric Auger <eric.auger@linaro.org>
Tested-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Now that struct _irqfd does not keep a reference to storage pointed
to by the irq_routing field of struct kvm, we can move the statement
that updates it out from under the irqfds.lock and put it in
kvm_set_irq_routing() instead. That means we then have to take a
srcu_read_lock on kvm->irq_srcu around the irqfd_update call in
kvm_irqfd_assign(), since holding the kvm->irqfds.lock no longer
ensures that that the routing can't change.
Combined with changing kvm_irq_map_gsi() and kvm_irq_map_chip_pin()
to take a struct kvm * argument instead of the pointer to the routing
table, this allows us to to move all references to kvm->irq_routing
into irqchip.c. That in turn allows us to move the definition of the
kvm_irq_routing_table struct into irqchip.c as well.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Tested-by: Eric Auger <eric.auger@linaro.org>
Tested-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This provides accessor functions for the KVM interrupt mappings, in
order to reduce the amount of code that accesses the fields of the
kvm_irq_routing_table struct, and restrict that code to one file,
virt/kvm/irqchip.c. The new functions are kvm_irq_map_gsi(), which
maps from a global interrupt number to a set of IRQ routing entries,
and kvm_irq_map_chip_pin, which maps from IRQ chip and pin numbers to
a global interrupt number.
This also moves the update of kvm_irq_routing_table::chip[][]
into irqchip.c, out of the various kvm_set_routing_entry
implementations. That means that none of the kvm_set_routing_entry
implementations need the kvm_irq_routing_table argument anymore,
so this removes it.
This does not change any locking or data lifetime rules.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Tested-by: Eric Auger <eric.auger@linaro.org>
Tested-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
In preparation to make the check_extension function available to VM scope
we add a struct kvm * argument to the function header and rename the function
accordingly. It will still be called from the /dev/kvm fd, but with a NULL
argument for struct kvm *.
Signed-off-by: Alexander Graf <agraf@suse.de>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Pull more scheduler updates from Ingo Molnar:
"Second round of scheduler changes:
- try-to-wakeup and IPI reduction speedups, from Andy Lutomirski
- continued power scheduling cleanups and refactorings, from Nicolas
Pitre
- misc fixes and enhancements"
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/deadline: Delete extraneous extern for to_ratio()
sched/idle: Optimize try-to-wake-up IPI
sched/idle: Simplify wake_up_idle_cpu()
sched/idle: Clear polling before descheduling the idle thread
sched, trace: Add a tracepoint for IPI-less remote wakeups
cpuidle: Set polling in poll_idle
sched: Remove redundant assignment to "rt_rq" in update_curr_rt(...)
sched: Rename capacity related flags
sched: Final power vs. capacity cleanups
sched: Remove remaining dubious usage of "power"
sched: Let 'struct sched_group_power' care about CPU capacity
sched/fair: Disambiguate existing/remaining "capacity" usage
sched/fair: Change "has_capacity" to "has_free_capacity"
sched/fair: Remove "power" from 'struct numa_stats'
sched: Fix signedness bug in yield_to()
sched/fair: Use time_after() in record_wakee()
sched/balancing: Reduce the rate of needless idle load balancing
sched/fair: Fix unlocked reads of some cfs_b->quota/period
yield_to() is supposed to return -ESRCH if there is no task to
yield to, but because the type is bool that is the same as returning
true.
The only place I see which cares is kvm_vcpu_on_spin().
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Raghavendra <raghavendra.kt@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: kvm@vger.kernel.org
Link: http://lkml.kernel.org/r/20140523102042.GA7267@mwanda
Signed-off-by: Ingo Molnar <mingo@kernel.org>
When starting lots of dataplane devices the bootup takes very long on
Christian's s390 with irqfd patches. With larger setups he is even
able to trigger some timeouts in some components. Turns out that the
KVM_SET_GSI_ROUTING ioctl takes very long (strace claims up to 0.1 sec)
when having multiple CPUs. This is caused by the synchronize_rcu and
the HZ=100 of s390. By changing the code to use a private srcu we can
speed things up. This patch reduces the boot time till mounting root
from 8 to 2 seconds on my s390 guest with 100 disks.
Uses of hlist_for_each_entry_rcu, hlist_add_head_rcu, hlist_del_init_rcu
are fine because they do not have lockdep checks (hlist_for_each_entry_rcu
uses rcu_dereference_raw rather than rcu_dereference, and write-sides
do not do rcu lockdep at all).
Note that we're hardly relying on the "sleepable" part of srcu. We just
want SRCU's faster detection of grace periods.
Testing was done by Andrew Theurer using netperf tests STREAM, MAERTS
and RR. The difference between results "before" and "after" the patch
has mean -0.2% and standard deviation 0.6%. Using a paired t-test on the
data points says that there is a 2.5% probability that the patch is the
cause of the performance difference (rather than a random fluctuation).
(Restricting the t-test to RR, which is the most likely to be affected,
changes the numbers to respectively -0.3% mean, 0.7% stdev, and 8%
probability that the numbers actually say something about the patch.
The probability increases mostly because there are fewer data points).
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Tested-by: Christian Borntraeger <borntraeger@de.ibm.com> # s390
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This patch enables the IBS facility when a single VCPU is running.
The facility is dynamically turned on/off as soon as other VCPUs
enter/leave the stopped state.
When this facility is operating, some instructions can be executed
faster for single-cpu guests.
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Reviewed-by: Dominik Dingel <dingel@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
This reverts commit 5befdc385d.
Since we will allow flush tlb out of mmu-lock in the later
patch
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
-------------------------
Linux does not use the ACC and F bits of the storage key. Newer Linux
versions also do not use the storage keys for dirty and reference
tracking. We can optimize the guest handling for those guests for faults
as well as page-in and page-out by simply not caring about the guest
visible storage key. We trap guest storage key instruction to enable
those keys only on demand.
Migration bitmap
Until now s390 never provided a proper dirty bitmap. Let's provide a
proper migration bitmap for s390. We also change the user dirty tracking
to a fault based mechanism. This makes the host completely independent
from the storage keys. Long term this will allow us to back guest memory
with large pages.
per-VM device attributes
------------------------
To avoid the introduction of new ioctls, let's provide the
attribute semanantic also on the VM-"device".
Userspace controlled CMMA
-------------------------
The CMMA assist is changed from "always on" to "on if requested" via
per-VM device attributes. In addition a callback to reset all usage
states is provided.
Proper guest DAT handling for intercepts
----------------------------------------
While instructions handled by SIE take care of all addressing aspects,
KVM/s390 currently does not care about guest address translation of
intercepts. This worked out fine, because
- the s390 Linux kernel has a 1:1 mapping between kernel virtual<->real
for all pages up to memory size
- intercepts happen only for a small amount of cases
- all of these intercepts happen to be in the kernel text for current
distros
Of course we need to be better for other intercepts, kernel modules etc.
We provide the infrastructure and rework all in-kernel intercepts to work
on logical addresses (paging etc) instead of real ones. The code has
been running internally for several months now, so it is time for going
public.
GDB support
-----------
We provide breakpoints, single stepping and watchpoints.
Fixes/Cleanups
--------------
- Improve program check delivery
- Factor out the handling of transactional memory on program checks
- Use the existing define __LC_PGM_TDB
- Several cleanups in the lowcore structure
- Documentation
NOTES
-----
- All patches touching base s390 are either ACKed or written by the s390
maintainers
- One base KVM patch "KVM: add kvm_is_error_gpa() helper"
- One patch introduces the notion of VM device attributes
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Merge tag 'kvm-s390-20140422' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into queue
Lazy storage key handling
-------------------------
Linux does not use the ACC and F bits of the storage key. Newer Linux
versions also do not use the storage keys for dirty and reference
tracking. We can optimize the guest handling for those guests for faults
as well as page-in and page-out by simply not caring about the guest
visible storage key. We trap guest storage key instruction to enable
those keys only on demand.
Migration bitmap
Until now s390 never provided a proper dirty bitmap. Let's provide a
proper migration bitmap for s390. We also change the user dirty tracking
to a fault based mechanism. This makes the host completely independent
from the storage keys. Long term this will allow us to back guest memory
with large pages.
per-VM device attributes
------------------------
To avoid the introduction of new ioctls, let's provide the
attribute semanantic also on the VM-"device".
Userspace controlled CMMA
-------------------------
The CMMA assist is changed from "always on" to "on if requested" via
per-VM device attributes. In addition a callback to reset all usage
states is provided.
Proper guest DAT handling for intercepts
----------------------------------------
While instructions handled by SIE take care of all addressing aspects,
KVM/s390 currently does not care about guest address translation of
intercepts. This worked out fine, because
- the s390 Linux kernel has a 1:1 mapping between kernel virtual<->real
for all pages up to memory size
- intercepts happen only for a small amount of cases
- all of these intercepts happen to be in the kernel text for current
distros
Of course we need to be better for other intercepts, kernel modules etc.
We provide the infrastructure and rework all in-kernel intercepts to work
on logical addresses (paging etc) instead of real ones. The code has
been running internally for several months now, so it is time for going
public.
GDB support
-----------
We provide breakpoints, single stepping and watchpoints.
Fixes/Cleanups
--------------
- Improve program check delivery
- Factor out the handling of transactional memory on program checks
- Use the existing define __LC_PGM_TDB
- Several cleanups in the lowcore structure
- Documentation
NOTES
-----
- All patches touching base s390 are either ACKed or written by the s390
maintainers
- One base KVM patch "KVM: add kvm_is_error_gpa() helper"
- One patch introduces the notion of VM device attributes
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Conflicts:
include/uapi/linux/kvm.h
It's quite common (in the s390 guest access code) to test if a guest
physical address points to a valid guest memory area or not.
So add a simple helper function in common code, since this might be
of interest for other architectures as well.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: Thomas Huth <thuth@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
With KVM, MMIO is much slower than PIO, due to the need to
do page walk and emulation. But with EPT, it does not have to be: we
know the address from the VMCS so if the address is unique, we can look
up the eventfd directly, bypassing emulation.
Unfortunately, this only works if userspace does not need to match on
access length and data. The implementation adds a separate FAST_MMIO
bus internally. This serves two purposes:
- minimize overhead for old userspace that does not use eventfd with lengtth = 0
- minimize disruption in other code (since we don't know the length,
devices on the MMIO bus only get a valid address in write, this
way we don't need to touch all devices to teach them to handle
an invalid length)
At the moment, this optimization only has effect for EPT on x86.
It will be possible to speed up MMIO for NPT and MMU using the same
idea in the future.
With this patch applied, on VMX MMIO EVENTFD is essentially as fast as PIO.
I was unable to detect any measureable slowdown to non-eventfd MMIO.
Making MMIO faster is important for the upcoming virtio 1.0 which
includes an MMIO signalling capability.
The idea was suggested by Peter Anvin. Lots of thanks to Gleb for
pre-review and suggestions.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
The maximum number for irq routes is currently 1024, which is a bit on
the small size for s390: We support up to 4 x 64k virtual devices with
up to 64 queues, and we need one route for each of the queues if we want
to operate it via irqfd.
Let's bump this to 4k on s390 for now, as this at least covers the saner
setups.
We need to find a more general solution, though, as we can't just grow
the routing table indefinitly.
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Introduce a new interrupt class for s390 adapter interrupts and enable
irqfds for s390.
This is depending on a new s390 specific vm capability, KVM_CAP_S390_IRQCHIP,
that needs to be enabled by userspace.
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
When this was introduced, kvm_flush_remote_tlbs() could be called
without holding mmu_lock. It is now acknowledged that the function
must be called before releasing mmu_lock, and all callers have already
been changed to do so.
There is no need to use smp_mb() and cmpxchg() any more.
Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
By setting a Kconfig option, the architecture can control when
guest notifications will be presented by the apf backend.
There is the default batch mechanism, working as before, where the vcpu
thread should pull in this information.
Opposite to this, there is now the direct mechanism, that will push the
information to the guest.
This way s390 can use an already existing architecture interface.
Still the vcpu thread should call check_completion to cleanup leftovers.
Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
This patch adds a floating irq controller as a kvm_device.
It will be necessary for migration of floating interrupts as well
as for hardening the reset code by allowing user space to explicitly
remove all pending floating interrupts.
Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
The function kvm_io_bus_read_cookie is defined but never used
in current in-tree code.
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Running 'make namespacecheck' found lots of functions that
should be declared static, since only used in one file.
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Support creating the ARM VGIC device through the KVM_CREATE_DEVICE
ioctl, which can then later be leveraged to use the
KVM_{GET/SET}_DEVICE_ATTR, which is useful both for setting addresses in
a more generic API than the ARM-specific one and is useful for
save/restore of VGIC state.
Adds KVM_CAP_DEVICE_CTRL to ARM capabilities.
Note that we change the check for creating a VGIC from bailing out if
any VCPUs were created, to bailing out if any VCPUs were ever run. This
is an important distinction that shouldn't break anything, but allows
creating the VGIC after the VCPUs have been created.
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Since the commit 15ad7146 ("KVM: Use the scheduler preemption notifiers
to make kvm preemptible"), the remaining stuff in this function is a
simple cond_resched() call with an extra need_resched() check which was
there to avoid dropping VCPUs unnecessarily. Now it is meaningless.
Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
We currently use some ad-hoc arch variables tied to legacy KVM device
assignment to manage emulation of instructions that depend on whether
non-coherent DMA is present. Create an interface for this, adapting
legacy KVM device assignment and adding VFIO via the KVM-VFIO device.
For now we assume that non-coherent DMA is possible any time we have a
VFIO group. Eventually an interface can be developed as part of the
VFIO external user interface to query the coherency of a group.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Default to operating in coherent mode. This simplifies the logic when
we switch to a model of registering and unregistering noncoherent I/O
with KVM.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
So far we've succeeded at making KVM and VFIO mostly unaware of each
other, but areas are cropping up where a connection beyond eventfds
and irqfds needs to be made. This patch introduces a KVM-VFIO device
that is meant to be a gateway for such interaction. The user creates
the device and can add and remove VFIO groups to it via file
descriptors. When a group is added, KVM verifies the group is valid
and gets a reference to it via the VFIO external user interface.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
We will use that in the later patch to find the kvm ops handler
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Page pinning is not mandatory in kvm async page fault processing since
after async page fault event is delivered to a guest it accesses page once
again and does its own GUP. Drop the FOLL_GET flag in GUP in async_pf
code, and do some simplifying in check/clear processing.
Suggested-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Gu zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: chai wen <chaiw.fnst@cn.fujitsu.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
The gfn_to_index function relies on huge page defines which either may
not make sense on systems that don't support huge pages or are defined
in an unconvenient way for other architectures. Since this is
x86-specific, move the function to arch/x86/include/asm/kvm_host.h.
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
In commit e935b8372c ("KVM: Convert kvm_lock to raw_spinlock"),
the kvm_lock was made a raw lock. However, the kvm mmu_shrink()
function tries to grab the (non-raw) mmu_lock within the scope of
the raw locked kvm_lock being held. This leads to the following:
BUG: sleeping function called from invalid context at kernel/rtmutex.c:659
in_atomic(): 1, irqs_disabled(): 0, pid: 55, name: kswapd0
Preemption disabled at:[<ffffffffa0376eac>] mmu_shrink+0x5c/0x1b0 [kvm]
Pid: 55, comm: kswapd0 Not tainted 3.4.34_preempt-rt
Call Trace:
[<ffffffff8106f2ad>] __might_sleep+0xfd/0x160
[<ffffffff817d8d64>] rt_spin_lock+0x24/0x50
[<ffffffffa0376f3c>] mmu_shrink+0xec/0x1b0 [kvm]
[<ffffffff8111455d>] shrink_slab+0x17d/0x3a0
[<ffffffff81151f00>] ? mem_cgroup_iter+0x130/0x260
[<ffffffff8111824a>] balance_pgdat+0x54a/0x730
[<ffffffff8111fe47>] ? set_pgdat_percpu_threshold+0xa7/0xd0
[<ffffffff811185bf>] kswapd+0x18f/0x490
[<ffffffff81070961>] ? get_parent_ip+0x11/0x50
[<ffffffff81061970>] ? __init_waitqueue_head+0x50/0x50
[<ffffffff81118430>] ? balance_pgdat+0x730/0x730
[<ffffffff81060d2b>] kthread+0xdb/0xe0
[<ffffffff8106e122>] ? finish_task_switch+0x52/0x100
[<ffffffff817e1e94>] kernel_thread_helper+0x4/0x10
[<ffffffff81060c50>] ? __init_kthread_worker+0x
After the previous patch, kvm_lock need not be a raw spinlock anymore,
so change it back.
Reported-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: kvm@vger.kernel.org
Cc: gleb@redhat.com
Cc: jan.kiszka@siemens.com
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
'.done' is used to mark the completion of 'async_pf_execute()', but
'cancel_work_sync()' returns true when the work was canceled, so we
use it instead.
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Page tables in a read-only memory slot will currently cause a triple
fault because the page walker uses gfn_to_hva and it fails on such a slot.
OVMF uses such a page table; however, real hardware seems to be fine with
that as long as the accessed/dirty bits are set. Save whether the slot
is readonly, and later check it when updating the accessed and dirty bits.
Reviewed-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
