Re: [PATCH v3 0/2] KVM: x86/mmu: Skip mmu_notifier changes when possible

[David Stevens]

These patches might be responsible for some instability in one of our
stress tests. I'll send an update once I figure out what's going on.

Thanks,
David

On Thu, Jan 28, 2021 at 9:48 PM Paolo Bonzini <pbonzini@xxxxxxxxxx> wrote:
>
> On 28/01/21 07:05, 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.
> >
> > 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                 | 16 ++++++++------
> >   arch/x86/kvm/mmu/paging_tmpl.h         |  7 ++++---
> >   include/linux/kvm_host.h               | 25 +++++++++++++++++++++-
> >   virt/kvm/kvm_main.c                    | 29 ++++++++++++++++++++++----
> >   6 files changed, 65 insertions(+), 16 deletions(-)
> >
>
> Queued, thanks.
>
> Paolo
>