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>

diff --git a/arch/x86/kvm/svm/avic.c b/arch/x86/kvm/svm/avic.c
index e7728b1..01c0e83 100644 (file)
--- a/arch/x86/kvm/svm/avic.c
+++ b/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);
 }