From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marcelo Tosatti Subject: KVM: SVM: force new asid on vcpu migration Date: Tue, 21 Jul 2009 12:47:45 -0300 Message-ID: <20090721154745.GA4188@amt.cnet> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: kvm To: Joerg Roedel Return-path: Received: from mx2.redhat.com ([66.187.237.31]:44881 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755466AbZGUPsf (ORCPT ); Tue, 21 Jul 2009 11:48:35 -0400 Content-Disposition: inline Sender: kvm-owner@vger.kernel.org List-ID: If a migrated vcpu matches the asid_generation value of the target pcpu, there will be no TLB flush via TLB_CONTROL_FLUSH_ALL_ASID. The check for vcpu.cpu in pre_svm_run is meaningless since svm_vcpu_load already updated it on schedule in. Such vcpu will VMRUN with stale TLB entries. Based on original patch from Joerg Roedel (http://patchwork.kernel.org/patch/10021/) Signed-off-by: Marcelo Tosatti diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 18085d3..90fe88f 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -739,6 +739,7 @@ static void svm_vcpu_load(struct kvm_vcpu *vcpu, int cpu) svm->vmcb->control.tsc_offset += delta; vcpu->cpu = cpu; kvm_migrate_timers(vcpu); + svm->asid_generation = 0; } for (i = 0; i < NR_HOST_SAVE_USER_MSRS; i++) @@ -1071,7 +1072,6 @@ static void new_asid(struct vcpu_svm *svm, struct svm_cpu_data *svm_data) svm->vmcb->control.tlb_ctl = TLB_CONTROL_FLUSH_ALL_ASID; } - svm->vcpu.cpu = svm_data->cpu; svm->asid_generation = svm_data->asid_generation; svm->vmcb->control.asid = svm_data->next_asid++; } @@ -2320,8 +2320,8 @@ static void pre_svm_run(struct vcpu_svm *svm) struct svm_cpu_data *svm_data = per_cpu(svm_data, cpu); svm->vmcb->control.tlb_ctl = TLB_CONTROL_DO_NOTHING; - if (svm->vcpu.cpu != cpu || - svm->asid_generation != svm_data->asid_generation) + /* FIXME: handle wraparound of asid_generation */ + if (svm->asid_generation != svm_data->asid_generation) new_asid(svm, svm_data); }