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| author | Sean Christopherson <seanjc@google.com> | 2021-10-21 17:49:27 -0700 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2021-10-22 11:20:16 -0400 |
| commit | 187c8833def8a191c7f01d7932eac1bd2ab84af1 (patch) | |
| tree | 5a76d19edb25bbc663c4eafec41c37875625bc68 /arch/x86/kvm/hyperv.c | |
| parent | ee49a89329711f84601bcb65ac8e8ef54fdac771 (diff) | |
| download | lwn-187c8833def8a191c7f01d7932eac1bd2ab84af1.tar.gz lwn-187c8833def8a191c7f01d7932eac1bd2ab84af1.zip | |
KVM: x86: Use rw_semaphore for APICv lock to allow vCPU parallelism
Use a rw_semaphore instead of a mutex to coordinate APICv updates so that
vCPUs responding to requests can take the lock for read and run in
parallel. Using a mutex forces serialization of vCPUs even though
kvm_vcpu_update_apicv() only touches data local to that vCPU or is
protected by a different lock, e.g. SVM's ir_list_lock.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211022004927.1448382-5-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.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c index 6f11cda2bfa4..4f15c0165c05 100644 --- a/arch/x86/kvm/hyperv.c +++ b/arch/x86/kvm/hyperv.c @@ -112,7 +112,7 @@ static void synic_update_vector(struct kvm_vcpu_hv_synic *synic, if (!!auto_eoi_old == !!auto_eoi_new) return; - mutex_lock(&vcpu->kvm->arch.apicv_update_lock); + down_write(&vcpu->kvm->arch.apicv_update_lock); if (auto_eoi_new) hv->synic_auto_eoi_used++; @@ -123,7 +123,7 @@ static void synic_update_vector(struct kvm_vcpu_hv_synic *synic, !hv->synic_auto_eoi_used, APICV_INHIBIT_REASON_HYPERV); - mutex_unlock(&vcpu->kvm->arch.apicv_update_lock); + up_write(&vcpu->kvm->arch.apicv_update_lock); } static int synic_set_sint(struct kvm_vcpu_hv_synic *synic, int sint, |