Re: [PATCH] KVM: TDX: Fix APIC MSR ranges in tdx_has_emulated_msr()

From: Dave Hansen

Date: Wed Mar 18 2026 - 15:43:10 EST


On 3/18/26 12:01, Dmytro Maluka wrote:
> + case X2APIC_MSR(APIC_ISR) ... X2APIC_MSR(APIC_ISR) + APIC_ISR_NR - 1:
> + case X2APIC_MSR(APIC_TMR) ... X2APIC_MSR(APIC_TMR) + APIC_ISR_NR - 1:
> + case X2APIC_MSR(APIC_IRR) ... X2APIC_MSR(APIC_IRR) + APIC_ISR_NR - 1:

Thanks for the patch, Dmytro.

<sigh>

So this code never worked (at least for a big chunk of the ranges.
Isaku, could you please go try to figure out if there are tests for this
somewhere, and why this never bit us?

It might also be handy to have a:

#define X2APIC_LAST_MSR(r) (X2APIC_MSR(x)+APIC_ISR_NR-1)

so that the resulting code is a bit more readable:

case X2APIC_MSR(APIC_IRR) ... X2APIC_LAST_MSR(APIC_IRR):

Dmytro, if you feel a burning need to respin this, don't let me stop
you. I can probably just fix this up when it gets applied, or Isaku can
make those changes and resend it too.