Re: [PATCH v3 3/7] KVM: nVMX: Make an event request when pending an MTF nested VM-Exit

From: Jim Mattson
Date: Mon Aug 22 2022 - 13:52:42 EST


On Mon, Aug 22, 2022 at 10:08 AM Paolo Bonzini <pbonzini@xxxxxxxxxx> wrote:
>
> From: Sean Christopherson <seanjc@xxxxxxxxxx>
>
> Set KVM_REQ_EVENT when MTF becomes pending to ensure that KVM will run
> through inject_pending_event() and thus vmx_check_nested_events() prior
> to re-entering the guest.
>
> MTF currently works by virtue of KVM's hack that calls
> kvm_check_nested_events() from kvm_vcpu_running(), but that hack will
> be removed in the near future. Until that call is removed, the patch
> introduces no functional change.
>
> Fixes: 5ef8acbdd687 ("KVM: nVMX: Emulate MTF when performing instruction emulation")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
> Reviewed-by: Maxim Levitsky <mlevitsk@xxxxxxxxxx>
> Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
> ---
What happens if live migration occurs before the KVM_REQ_EVENT is processed?