KVM: Mask function7 ebx against host capability word9

This patch masks CPUID leaf 7 ebx against host capability word9.

Signed-off-by: Yang, Wei <wei.y.yang@intel.com>
Signed-off-by: Shan, Haitao <haitao.shan@intel.com>
Signed-off-by: Li, Xin <xin.li@intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index ba5cd27b429a48b3494b39914f5197f71e2482db..ff4623b1b10242da251e409f9cbb8813b8828326 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -2359,6 +2359,10 @@ static void do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
                F(ACE2) | F(ACE2_EN) | F(PHE) | F(PHE_EN) |
                F(PMM) | F(PMM_EN);
 
+       /* cpuid 7.0.ebx */
+       const u32 kvm_supported_word9_x86_features =
+               F(SMEP);
+
        /* all calls to cpuid_count() should be made on the same cpu */
        get_cpu();
        do_cpuid_1_ent(entry, function, index);
@@ -2393,7 +2397,7 @@ static void do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
                }
                break;
        }
-       /* function 4 and 0xb have additional index. */
+       /* function 4 has additional index. */
        case 4: {
                int i, cache_type;
 
@@ -2410,8 +2414,22 @@ static void do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
                }
                break;
        }
+       case 7: {
+               entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
+               /* Mask ebx against host capbability word 9 */
+               if (index == 0) {
+                       entry->ebx &= kvm_supported_word9_x86_features;
+                       cpuid_mask(&entry->ebx, 9);
+               } else
+                       entry->ebx = 0;
+               entry->eax = 0;
+               entry->ecx = 0;
+               entry->edx = 0;
+               break;
+       }
        case 9:
                break;
+       /* function 0xb has additional index. */
        case 0xb: {
                int i, level_type;