KVM: x86: nSVM: optimize svm_set_x2apic_msr_interception

- Avoid toggling the x2apic msr interception if it is already up to date.

- Avoid touching L0 msr bitmap when AVIC is inhibited on entry to
  the guest mode, because in this case the guest usually uses its
  own msr bitmap.

  Later on VM exit, the 1st optimization will allow KVM to skip
  touching the L0 msr bitmap as well.

Reviewed-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Tested-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20220519102709.24125-18-suravee.suthikulpanit@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index ccaae7d160cd..558ca1296d36 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -276,6 +276,8 @@ struct vcpu_svm {
 	struct vcpu_sev_es_state sev_es;
 
 	bool guest_state_loaded;
+
+	bool x2avic_msrs_intercepted;
 };
 
 struct svm_cpu_data {