Re: [PATCH 1/7] KVM: VMX: read idt_vectoring_info a bit earlier

From: Maxim Levitsky
Date: Wed Feb 17 2021 - 11:20:12 EST


On Wed, 2021-02-17 at 17:06 +0100, Paolo Bonzini wrote:
> On 17/02/21 15:57, Maxim Levitsky wrote:
> > diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
> > index b3e36dc3f164..e428d69e21c0 100644
> > --- a/arch/x86/kvm/vmx/vmx.c
> > +++ b/arch/x86/kvm/vmx/vmx.c
> > @@ -6921,13 +6921,15 @@ static fastpath_t vmx_vcpu_run(struct kvm_vcpu *vcpu)
> > if (unlikely((u16)vmx->exit_reason.basic == EXIT_REASON_MCE_DURING_VMENTRY))
> > kvm_machine_check();
> >
> > + if (likely(!vmx->exit_reason.failed_vmentry))
> > + vmx->idt_vectoring_info = vmcs_read32(IDT_VECTORING_INFO_FIELD);
> > +
>
> Any reason for the if?

Sean Christopherson asked me to do this to avoid updating idt_vectoring_info on failed
VM entry, to keep things as they were logically before this patch.

Best regards,
Maxim Levitsky

>
> Paolo
>