Re: [PATCH 0/3] KVM: x86: Use "standard" mmu_notifier hook for APIC page

From: Sean Christopherson
Date: Tue Jun 06 2023 - 20:55:26 EST


On Thu, 01 Jun 2023 18:15:15 -0700, Sean Christopherson wrote:
> Convert VMX's handling of mmu_notifier invalidations of the APIC-access page
> from invalidate_range() to KVM's standard invalidate_range_{start,end}().
>
> KVM (ab)uses invalidate_range() to fudge around not stalling vCPUs until
> relevant in-flight invalidations complete. Abusing invalidate_range() works,
> but it requires one-off code in KVM, sets a bad precedent in KVM, and is
> blocking improvements to mmu_notifier's definition of invalidate_range()
> due to KVM's usage diverging wildly from the original intent of notifying
> IOMMUs of changes to shared page tables.
>
> [...]

Applied to kvm-x86 vmx, thanks!

[1/3] KVM: VMX: Retry APIC-access page reload if invalidation is in-progress
https://github.com/kvm-x86/linux/commit/878940b33d76
[2/3] KVM: x86: Use standard mmu_notifier invalidate hooks for APIC access page
https://github.com/kvm-x86/linux/commit/0a8a5f2c8c26
[3/3] KVM: x86/mmu: Trigger APIC-access page reload iff vendor code cares
https://github.com/kvm-x86/linux/commit/0a3869e14d4a

--
https://github.com/kvm-x86/linux/tree/next
https://github.com/kvm-x86/linux/tree/fixes