lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Tue, 10 Aug 2021 23:52:48 +0300 From: Maxim Levitsky <mlevitsk@...hat.com> To: kvm@...r.kernel.org Cc: Jim Mattson <jmattson@...gle.com>, linux-kernel@...r.kernel.org, Wanpeng Li <wanpengli@...cent.com>, Borislav Petkov <bp@...en8.de>, Joerg Roedel <joro@...tes.org>, Suravee Suthikulpanit <suravee.suthikulpanit@....com>, "H. Peter Anvin" <hpa@...or.com>, Paolo Bonzini <pbonzini@...hat.com>, Thomas Gleixner <tglx@...utronix.de>, Ingo Molnar <mingo@...hat.com>, Vitaly Kuznetsov <vkuznets@...hat.com>, Sean Christopherson <seanjc@...gle.com>, x86@...nel.org (maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)), Maxim Levitsky <mlevitsk@...hat.com> Subject: [PATCH v4 13/16] 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 <mlevitsk@...hat.com> --- 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 b6185921fe44..e2ec45e3dc0a 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); -- 2.26.3
Powered by blists - more mailing lists