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authorPaolo Bonzini <pbonzini@redhat.com>2017-08-24 11:59:31 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-08-30 10:21:45 +0200
commit275f3033ccf6114f3c7d4535665fcf7bdcc9f04e (patch)
treed8296f9e61f47aa7b600ea5c528a91af5911acf0
parentcfb917a17d3df75243199ad8bad7e9505fd79468 (diff)
KVM: x86: block guest protection keys unless the host has them enabled
commit c469268cd523245cc58255f6696e0c295485cb0b upstream. If the host has protection keys disabled, we cannot read and write the guest PKRU---RDPKRU and WRPKRU fail with #GP(0) if CR4.PKE=0. Block the PKU cpuid bit in that case. This ensures that guest_CR4.PKE=1 implies host_CR4.PKE=1. Fixes: 1be0e61c1f255faaeab04a390e00c8b9b9042870 Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--arch/x86/kvm/cpuid.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 649d8f2c1e40..91af75e37306 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -456,7 +456,7 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
entry->ecx &= kvm_cpuid_7_0_ecx_x86_features;
cpuid_mask(&entry->ecx, CPUID_7_ECX);
/* PKU is not yet implemented for shadow paging. */
- if (!tdp_enabled)
+ if (!tdp_enabled || !boot_cpu_has(X86_FEATURE_OSPKE))
entry->ecx &= ~F(PKU);
} else {
entry->ebx = 0;