diff options
| author | Sean Christopherson <seanjc@google.com> | 2021-12-08 01:52:34 +0000 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2022-02-10 13:47:09 -0500 |
| commit | f15756428ded1ee01d95934057a6e89c2d450bbb (patch) | |
| tree | 3c58449a1758a3b8488602afd75ca33e2186662b | |
| parent | 7446cfebe8be61874549a26b26c203deda2afbac (diff) | |
KVM: x86: Skip APICv update if APICv is disable at the module level
Bail from the APICv update paths _before_ taking apicv_update_lock if
APICv is disabled at the module level. kvm_request_apicv_update() in
particular is invoked from multiple paths that can be reached without
APICv being enabled, e.g. svm_enable_irq_window(), and taking the
rw_sem for write when APICv is disabled may introduce unnecessary
contention and stalls.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211208015236.1616697-25-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| -rw-r--r-- | arch/x86/kvm/hyperv.c | 3 | ||||
| -rw-r--r-- | arch/x86/kvm/x86.c | 3 |
2 files changed, 6 insertions, 0 deletions
diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c index 6e38a7d22e97..0bc7488f2b39 100644 --- a/arch/x86/kvm/hyperv.c +++ b/arch/x86/kvm/hyperv.c @@ -112,6 +112,9 @@ static void synic_update_vector(struct kvm_vcpu_hv_synic *synic, if (!!auto_eoi_old == !!auto_eoi_new) return; + if (!enable_apicv) + return; + down_write(&vcpu->kvm->arch.apicv_update_lock); if (auto_eoi_new) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 3b7479bd3404..04d3f8abc3ad 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -9715,6 +9715,9 @@ void __kvm_request_apicv_update(struct kvm *kvm, bool activate, ulong bit) void kvm_request_apicv_update(struct kvm *kvm, bool activate, ulong bit) { + if (!enable_apicv) + return; + down_write(&kvm->arch.apicv_update_lock); __kvm_request_apicv_update(kvm, activate, bit); up_write(&kvm->arch.apicv_update_lock); |