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authorSean Christopherson <seanjc@google.com>2021-12-08 01:52:34 +0000
committerPaolo Bonzini <pbonzini@redhat.com>2022-02-10 13:47:09 -0500
commitf15756428ded1ee01d95934057a6e89c2d450bbb (patch)
tree3c58449a1758a3b8488602afd75ca33e2186662b /arch/x86/kvm/hyperv.c
parent7446cfebe8be61874549a26b26c203deda2afbac (diff)
downloadlinux-f15756428ded1ee01d95934057a6e89c2d450bbb.tar.bz2
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>
Diffstat (limited to 'arch/x86/kvm/hyperv.c')
-rw-r--r--arch/x86/kvm/hyperv.c3
1 files changed, 3 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)