Commit 7dc92117 authored by Andy Whitcroft's avatar Andy Whitcroft Committed by Kleber Sacilotto de Souza

Revert "x86/svm: Set IBPB when running a different VCPU"

CVE-2017-5753 (revert embargoed)
CVE-2017-5715 (revert embargoed)

This reverts commit 8c36ea34.
Signed-off-by: default avatarAndy Whitcroft <apw@canonical.com>
Signed-off-by: default avatarKleber Sacilotto de Souza <kleber.souza@canonical.com>
parent ef09993f
......@@ -414,8 +414,6 @@ struct svm_cpu_data {
struct kvm_ldttss_desc *tss_desc;
struct page *save_area;
struct vmcb *current_vmcb;
};
static DEFINE_PER_CPU(struct svm_cpu_data *, svm_data);
......@@ -1215,19 +1213,11 @@ static void svm_free_vcpu(struct kvm_vcpu *vcpu)
__free_pages(virt_to_page(svm->nested.msrpm), MSRPM_ALLOC_ORDER);
kvm_vcpu_uninit(vcpu);
kmem_cache_free(kvm_vcpu_cache, svm);
/*
* The VMCB could be recycled, causing a false negative in svm_vcpu_load;
* block speculative execution.
*/
if (ibpb_inuse)
wrmsrl(MSR_IA32_PRED_CMD, FEATURE_SET_IBPB);
}
static void svm_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
{
struct vcpu_svm *svm = to_svm(vcpu);
struct svm_cpu_data *sd = per_cpu(svm_data, cpu);
int i;
if (unlikely(cpu != vcpu->cpu)) {
......@@ -1252,12 +1242,6 @@ static void svm_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
wrmsrl(MSR_AMD64_TSC_RATIO, tsc_ratio);
}
}
if (sd->current_vmcb != svm->vmcb) {
sd->current_vmcb = svm->vmcb;
if (ibpb_inuse)
wrmsrl(MSR_IA32_PRED_CMD, FEATURE_SET_IBPB);
}
}
static void svm_vcpu_put(struct kvm_vcpu *vcpu)
......
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