KVM: SVM: call avic_vcpu_load/avic_vcpu_put when enabling/disabling AVIC

Currently it is possible to have the following scenario:

1. AVIC is disabled by svm_refresh_apicv_exec_ctrl
2. svm_vcpu_blocking calls avic_vcpu_put which does nothing
3. svm_vcpu_unblocking enables the AVIC (due to KVM_REQ_APICV_UPDATE)
   and then calls avic_vcpu_load
4. warning is triggered in avic_vcpu_load since
   AVIC_PHYSICAL_ID_ENTRY_IS_RUNNING_MASK was never cleared

While it is possible to just remove the warning, it seems to be more robust
to fully disable/enable AVIC in svm_refresh_apicv_exec_ctrl by calling the
avic_vcpu_load/avic_vcpu_put
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20210810205251.424103-16-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/svm/avic.c

@@ -651,6 +651,11 @@ void svm_refresh_apicv_exec_ctrl(struct kvm_vcpu *vcpu)
 	}
 	vmcb_mark_dirty(vmcb, VMCB_AVIC);
 
+	if (activated)
+		avic_vcpu_load(vcpu, vcpu->cpu);
+	else
+		avic_vcpu_put(vcpu);
+
 	svm_set_pi_irte_mode(vcpu, activated);
 }