According to volume 2 of the SDM, output registers %ebx, %ecx, and
%edx of CPUID leaf 9 (the direct cache access information leaf) are
reserved. Since we have no way of knowing what these fields will be
used for, they should not be whitelisted.
Fixes: 24c82e576b78 ("KVM: Sanitize cpuid")
Suggested-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
Signed-off-by: Jim Mattson <jmattson@xxxxxxxxxx>
---
arch/x86/kvm/cpuid.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 183f40cd3362..d9b6d90fd062 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -510,6 +510,7 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
break;
}
case 9:
+ entry->ebx = entry->ecx = entry->edx = 0;
break;
case 0xa: { /* Architectural Performance Monitoring */
struct x86_pmu_capability cap;
--
2.20.1.791.gb4d0f1c61a-goog
