KVM: SVM: Do not activate AVIC for SEV-enabled guest

Since current AVIC implementation cannot support encrypted memory,
inhibit AVIC for SEV-enabled guest.
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Message-Id: <20220408133710.54275-1-suravee.suthikulpanit@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/include/asm/kvm_host.h

@@ -1052,6 +1052,7 @@ enum kvm_apicv_inhibit {
 	APICV_INHIBIT_REASON_X2APIC,
 	APICV_INHIBIT_REASON_BLOCKIRQ,
 	APICV_INHIBIT_REASON_ABSENT,
+	APICV_INHIBIT_REASON_SEV,
 };
 
 struct kvm_arch {

arch/x86/kvm/svm/avic.c

@@ -837,7 +837,8 @@ bool avic_check_apicv_inhibit_reasons(enum kvm_apicv_inhibit reason)
 			  BIT(APICV_INHIBIT_REASON_IRQWIN) |
 			  BIT(APICV_INHIBIT_REASON_PIT_REINJ) |
 			  BIT(APICV_INHIBIT_REASON_X2APIC) |
-			  BIT(APICV_INHIBIT_REASON_BLOCKIRQ);
+			  BIT(APICV_INHIBIT_REASON_BLOCKIRQ) |
+			  BIT(APICV_INHIBIT_REASON_SEV);
 
 	return supported & BIT(reason);
 }

arch/x86/kvm/svm/sev.c

@@ -260,6 +260,8 @@ static int sev_guest_init(struct kvm *kvm, struct kvm_sev_cmd *argp)
 	INIT_LIST_HEAD(&sev->regions_list);
 	INIT_LIST_HEAD(&sev->mirror_vms);
 
+	kvm_set_apicv_inhibit(kvm, APICV_INHIBIT_REASON_SEV);
+
 	return 0;
 
 e_free: