Re: [RFC PATCH v3 02/27] x86/apic: Drop savic_eoi() in favor of native_apic_msr_eoi() for Secure AVIC

[Borislav Petkov]

On Wed, Jul 08, 2026 at 12:02:00PM +0530, Naveen N Rao (AMD) wrote:
> Drop savic_eoi() in favor of using the native helper that writes to the
> APIC_EOI MSR. savic_eoi() was added mainly to be able to handle
> level-triggered interrupts. However, it relies on APIC_TMR indicating a
> vector to be level-triggered, but APIC_TMR can never have a bit set
> since it is only updated when the LAPIC accepts a level-triggered
> interrupt. In the case of a Secure AVIC SEV-SNP guest, all
> level-triggered interrupt sources are in the VMM (emulated IOAPIC
> primarily) and KVM accepts them on behalf of the guest resulting in the
> APIC_TMR in KVM APIC backing page having a bit set. This is never seen
> by the guest, which has its own private APIC backing page. As such, the
> savic_eoi() handler is dead code. Remove it.

So this sounds to me like we forgot some detail while spec-cing SAVIC. Or
maybe for SAVIC, KVM should not accept them on behalf of the guest anymore.
But what do I know...

Btw, In the future, pls split such conglomerate commit messages into paragraphs for
better/easier readability.

Thx.

-- 
Regards/Gruss,
    Boris.

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