Re: [PATCH v2 0/5] KVM: SVM: Fix x2AVIC MSR interception issues

[Naveen N Rao <naveen@kernel.org>]

On Wed, May 06, 2026 at 11:47:41AM -0700, Sean Christopherson wrote:
> Fix a variety of bugs in SVM's handling of x2APIC MSR passthrough for x2AVIC,
> where KVM disables interception for MSR accesses that aren't accelerated by
> hardware (pointless and suboptimal), and also does NOT disable interception
> for practically any of the "range of vectors" MSRs, i.e. IRR, ISR, and TMR.
> 
> Found by inspection when reviewing a TDX patch to fix a bug where KVM botched
> the "range of vectors"[*] (I was curious how other KVM code handled the ranges;
> wasn't expecting this...).
> 
> Note, I tagged all of this for stable, but I could be convinced these fixes
> shouldn't be sent to LTS trees.  Patch 3 in particular doesn't truly fix
> anything, though I definitely don't like relying on poorly documented behavior.
> 
> Note #2, the diff stats are misleading due to the hacks, the "real" stats are:
> 
>   arch/x86/kvm/svm/avic.c | 51 ++++++++++++++++-----------------------------------
>   1 file changed, 16 insertions(+), 35 deletions(-)

For the series (except the selftests), with the minor changes we 
discussed:
Reviewed-by: Naveen N Rao (AMD) <naveen@kernel.org>


- Naveen