Re: [PATCH v4 0/2] KVM: x86/mmu: Skip mmu_notifier changes when possible

Paolo Bonzini
2021-02-22T18:20:21Z

On 22/02/21 03:45, David Stevens wrote:
> These patches reduce how often mmu_notifier updates block guest page
> faults. The primary benefit of this is the reduction in the likelihood
> of extreme latency when handling a page fault due to another thread
> having been preempted while modifying host virtual addresses.
>
> v3 -> v4:
> - Fix bug by skipping prefetch during invalidation
>
> v2 -> v3:
> - Added patch to skip check for MMIO page faults
> - Style changes
>
> David Stevens (1):
> KVM: x86/mmu: Consider the hva in mmu_notifier retry
>
> Sean Christopherson (1):
> KVM: x86/mmu: Skip mmu_notifier check when handling MMIO page fault
>
> arch/powerpc/kvm/book3s_64_mmu_hv.c | 2 +-
> arch/powerpc/kvm/book3s_64_mmu_radix.c | 2 +-
> arch/x86/kvm/mmu/mmu.c | 23 ++++++++++++++------
> arch/x86/kvm/mmu/paging_tmpl.h | 7 ++++---
> include/linux/kvm_host.h | 25 +++++++++++++++++++++-
> virt/kvm/kvm_main.c | 29 ++++++++++++++++++++++----
> 6 files changed, 72 insertions(+), 16 deletions(-)
>

Rebased, and queued with the fix that Sean suggested.

Paolo