From 06ef813466c63ff1a61b5f99592e58d049c2c1ac Mon Sep 17 00:00:00 2001 From: Maxim Levitsky Date: Tue, 10 Aug 2021 23:52:48 +0300 Subject: [PATCH] KVM: SVM: avoid refreshing avic if its state didn't change Since AVIC can be inhibited and uninhibited rapidly it is possible that we have nothing to do by the time the svm_refresh_apicv_exec_ctrl is called. Detect and avoid this, which will be useful when we will start calling avic_vcpu_load/avic_vcpu_put when the avic inhibition state changes. Signed-off-by: Maxim Levitsky Message-Id: <20210810205251.424103-14-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini --- arch/x86/kvm/x86.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 89e666e5a707..bf8cb1021d11 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -9239,12 +9239,18 @@ void kvm_make_scan_ioapic_request(struct kvm *kvm) void kvm_vcpu_update_apicv(struct kvm_vcpu *vcpu) { + bool activate; + if (!lapic_in_kernel(vcpu)) return; mutex_lock(&vcpu->kvm->arch.apicv_update_lock); - vcpu->arch.apicv_active = kvm_apicv_activated(vcpu->kvm); + activate = kvm_apicv_activated(vcpu->kvm); + if (vcpu->arch.apicv_active == activate) + goto out; + + vcpu->arch.apicv_active = activate; kvm_apic_update_apicv(vcpu); static_call(kvm_x86_refresh_apicv_exec_ctrl)(vcpu); @@ -9257,6 +9263,7 @@ void kvm_vcpu_update_apicv(struct kvm_vcpu *vcpu) if (!vcpu->arch.apicv_active) kvm_make_request(KVM_REQ_EVENT, vcpu); +out: mutex_unlock(&vcpu->kvm->arch.apicv_update_lock); } EXPORT_SYMBOL_GPL(kvm_vcpu_update_apicv);