On 12/10/21 13:47, Maxim Levitsky wrote:
If we scan vIRR here and see no bits, and*then* disable AVIC, there is a window where the they could legit be turned on without any cpu errata, and we will not have irr_pending == true, and thus the following KVM_REQ_EVENT will make no difference.
Right.
Not touching irr_pending and letting just the KVM_REQ_EVENT do the work will work too,
Yeah, I think that's preferrable. irr_pending == true is a conservative setting that works; irr_pending will be evaluated again on the first call to apic_clear_irr and that's enough.
With that justification, you don't need to reorder the call to kvm_apic_update_apicv to be after kvm_x86_refresh_apicv_exec_ctrl.
Paolo and if the avic errata is present, reduce slightly
the chances of it happening.
