From: "Yang, Wei Y" <wei.y.yang@xxxxxxxxx>
This patchset enables a new CPU feature SMEP (Supervisor Mode Execution
Protection) in QEMU-KVM. SMEP prevents kernel from executing code in application.
Updated Intel SDM describes this CPU feature. The document will be published soon.
SMEP is identified by CPUID leaf 7 EBX[7], which is 0 before. Get the right value by query KVM kernel module, so that guest can get SMEP through CPUID.
Signed-off-by: Yang, Wei <wei.y.yang@xxxxxxxxx>
Singed-off-by: Shan, Haitao <haitao.shan@xxxxxxxxx>
Singed-off-by: Li, Xin <xin.li@xxxxxxxxx>
Signed-off-by: Marcelo Tosatti <mtosatti@xxxxxxxxxx>
---
target-i386/cpuid.c | 13 +++++++++++++
1 files changed, 13 insertions(+), 0 deletions(-)
diff --git a/target-i386/cpuid.c b/target-i386/cpuid.c
index 40a73c7..79e7580 100644
--- a/target-i386/cpuid.c
+++ b/target-i386/cpuid.c
@@ -1142,6 +1142,19 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, uint32_t count,
*ecx = 0;
*edx = 0;
break;
+ case 7:
+ if (kvm_enabled()) {
+ *eax = kvm_arch_get_supported_cpuid(env, 0x7, count, R_EAX);
+ *ebx = kvm_arch_get_supported_cpuid(env, 0x7, count, R_EBX);
+ *ecx = kvm_arch_get_supported_cpuid(env, 0x7, count, R_ECX);
+ *edx = kvm_arch_get_supported_cpuid(env, 0x7, count, R_EDX);
+ } else {
+ *eax = 0;
+ *ebx = 0;
+ *ecx = 0;
+ *edx = 0;
+ }
+ break;
case 9:
/* Direct Cache Access Information Leaf */
*eax = 0; /* Bits 0-31 in DCA_CAP MSR */
--
1.7.5.2
--
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