KVM: SVM: Refresh AVIC configuration when changing APIC mode

AMD AVIC can support xAPIC and x2APIC virtualization,
which requires changing x2APIC bit VMCB and MSR intercepton
for x2APIC MSRs. Therefore, call avic_refresh_apicv_exec_ctrl()
to refresh configuration accordingly.

Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Message-Id: <20220519102709.24125-10-suravee.suthikulpanit@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/svm/avic.c

@@ -675,6 +675,18 @@ void avic_apicv_post_state_restore(struct kvm_vcpu *vcpu)
 	avic_handle_ldr_update(vcpu);
 }
 
+void avic_set_virtual_apic_mode(struct kvm_vcpu *vcpu)
+{
+	if (!lapic_in_kernel(vcpu) || avic_mode == AVIC_MODE_NONE)
+		return;
+
+	if (kvm_get_apic_mode(vcpu) == LAPIC_MODE_INVALID) {
+		WARN_ONCE(true, "Invalid local APIC state (vcpu_id=%d)", vcpu->vcpu_id);
+		return;
+	}
+	avic_refresh_apicv_exec_ctrl(vcpu);
+}
+
 static int avic_set_pi_irte_mode(struct kvm_vcpu *vcpu, bool activate)
 {
 	int ret = 0;

arch/x86/kvm/svm/svm.c

@@ -4793,6 +4793,7 @@ static struct kvm_x86_ops svm_x86_ops __initdata = {
 	.enable_nmi_window = svm_enable_nmi_window,
 	.enable_irq_window = svm_enable_irq_window,
 	.update_cr8_intercept = svm_update_cr8_intercept,
+	.set_virtual_apic_mode = avic_set_virtual_apic_mode,
 	.refresh_apicv_exec_ctrl = avic_refresh_apicv_exec_ctrl,
 	.check_apicv_inhibit_reasons = avic_check_apicv_inhibit_reasons,
 	.apicv_post_state_restore = avic_apicv_post_state_restore,

arch/x86/kvm/svm/svm.h

@@ -634,6 +634,8 @@ void avic_vcpu_blocking(struct kvm_vcpu *vcpu);
 void avic_vcpu_unblocking(struct kvm_vcpu *vcpu);
 void avic_ring_doorbell(struct kvm_vcpu *vcpu);
 unsigned long avic_vcpu_get_apicv_inhibit_reasons(struct kvm_vcpu *vcpu);
+void avic_set_virtual_apic_mode(struct kvm_vcpu *vcpu);
+
 
 /* sev.c */