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

From: Paolo Bonzini
Date: Mon Feb 22 2021 - 13:20:48 EST


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