From b652de1e3dfb3b49e539e88a684a68e333e1bd7c Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Tue, 1 Mar 2022 09:05:09 -0800 Subject: KVM: SVM: Disable preemption across AVIC load/put during APICv refresh Disable preemption when loading/putting the AVIC during an APICv refresh. If the vCPU task is preempted and migrated ot a different pCPU, the unprotected avic_vcpu_load() could set the wrong pCPU in the physical ID cache/table. Pull the necessary code out of avic_vcpu_{,un}blocking() and into a new helper to reduce the probability of introducing this exact bug a third time. Fixes: df7e4827c549 ("KVM: SVM: call avic_vcpu_load/avic_vcpu_put when enabling/disabling AVIC") Cc: stable@vger.kernel.org Reported-by: Maxim Levitsky Signed-off-by: Sean Christopherson Signed-off-by: Paolo Bonzini --- arch/x86/kvm/svm/svm.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/x86/kvm/svm/svm.c') diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 7038c76fa841..c5e3f219803e 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -1318,13 +1318,13 @@ static void svm_vcpu_load(struct kvm_vcpu *vcpu, int cpu) indirect_branch_prediction_barrier(); } if (kvm_vcpu_apicv_active(vcpu)) - avic_vcpu_load(vcpu, cpu); + __avic_vcpu_load(vcpu, cpu); } static void svm_vcpu_put(struct kvm_vcpu *vcpu) { if (kvm_vcpu_apicv_active(vcpu)) - avic_vcpu_put(vcpu); + __avic_vcpu_put(vcpu); svm_prepare_host_switch(vcpu); -- cgit