KVM: x86: Introducing kvm_x86_ops.apicv_post_state_restore

Adding kvm_x86_ops hooks to allow APICv to do post state restore.
This is required to support VM save and restore feature.

Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/include/asm/kvm_host.h

@@ -1004,6 +1004,7 @@ struct kvm_x86_ops {
 
 	int (*update_pi_irte)(struct kvm *kvm, unsigned int host_irq,
 			      uint32_t guest_irq, bool set);
+	void (*apicv_post_state_restore)(struct kvm_vcpu *vcpu);
 };
 
 struct kvm_arch_async_pf {

arch/x86/kvm/lapic.c

@@ -1961,6 +1961,8 @@ void kvm_apic_post_state_restore(struct kvm_vcpu *vcpu,
 				1 : count_vectors(apic->regs + APIC_ISR);
 	apic->highest_isr_cache = -1;
 	if (vcpu->arch.apicv_active) {
+		if (kvm_x86_ops->apicv_post_state_restore)
+			kvm_x86_ops->apicv_post_state_restore(vcpu);
 		kvm_x86_ops->hwapic_irr_update(vcpu,
 				apic_find_highest_irr(apic));
 		kvm_x86_ops->hwapic_isr_update(vcpu->kvm,

arch/x86/kvm/svm.c

@@ -4834,6 +4834,15 @@ static void svm_sched_in(struct kvm_vcpu *vcpu, int cpu)
 {
 }
 
+static inline void avic_post_state_restore(struct kvm_vcpu *vcpu)
+{
+	if (avic_handle_apic_id_update(vcpu) != 0)
+		return;
+	if (avic_handle_dfr_update(vcpu) != 0)
+		return;
+	avic_handle_ldr_update(vcpu);
+}
+
 static struct kvm_x86_ops svm_x86_ops = {
 	.cpu_has_kvm_support = has_svm,
 	.disabled_by_bios = is_disabled,
@@ -4914,6 +4923,7 @@ static struct kvm_x86_ops svm_x86_ops = {
 	.sync_pir_to_irr = svm_sync_pir_to_irr,
 	.hwapic_irr_update = svm_hwapic_irr_update,
 	.hwapic_isr_update = svm_hwapic_isr_update,
+	.apicv_post_state_restore = avic_post_state_restore,
 
 	.set_tss_addr = svm_set_tss_addr,
 	.get_tdp_level = get_npt_level,