Re: [PATCH 3/3] KVM: SVM: Only disable x2AVIC WRMSR interception for MSRs that are accelerated

Naveen N Rao
2026-04-10T16:53:48Z

On Thu, Apr 09, 2026 at 03:24:49PM -0700, Sean Christopherson wrote:
> When x2AVIC is enabled, disable WRMSR interception only for MSRs that are
> actually accelerated by hardware. Disabling interception for MSRs that
> aren't accelerated is functionally "fine", but very suboptimal as many
> accesses generate AVIC_UNACCELERATED_ACCESS fault #VMEXITs, which requires
> KVM to decode the instruction to figure out what the guest was trying to
> access.

Not sure I follow: as far as I can see, most writes are actually trapped
except for MSRs that are supposed to be RO?

- Naveen