On Tue, Feb 15, 2022, Chao Gao wrote:
> > case APIC_SELF_IPI:
> >- if (apic_x2apic_mode(apic)) {
> >- kvm_lapic_reg_write(apic, APIC_ICR,
> >- APIC_DEST_SELF | (val & APIC_VECTOR_MASK));
> >- } else
> >+ if (apic_x2apic_mode(apic))
> >+ kvm_x2apic_icr_write(apic, APIC_DEST_SELF | (val & APIC_VECTOR_MASK));
> >+ else
>
> The original code looks incorrect. Emulating writes to SELF_IPI by writes to
> ICR has an unwanted side-effect: the value of ICR in vAPIC page gets changed.
>
> It is better to use kvm_apic_send_ipi() directly.
Agreed, the SDM lists SELF_IPI as write-only, with no associated MMIO offset, so
it should have no visible side effect in the vAPIC. I'll add a patch to fix this.
Thanks!
