diff mbox series

[7/9] i386/cpu: Suppress CPUID values not defined by Intel

Message ID 20240814075431.339209-8-xiaoyao.li@intel.com (mailing list archive)
State New, archived
Headers show
Series Misc patches for x86 CPUID | expand

Commit Message

Xiaoyao Li Aug. 14, 2024, 7:54 a.m. UTC 
Some CPUID leaves are defined by AMD while it also gets exposed to Intel
VMs by QEMU. It causes no issue with current VMs however it will not work
with Intel TDX because these CPUID leaves are enforced by TDX module as
reserved.

Stop to advertise them to Intel VMs when vendor_cpuid_only is true.

Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
---
 target/i386/cpu.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)
diff mbox series

Patch

diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index 7a4835289760..fed805e04aeb 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -6863,12 +6863,16 @@  void cpu_x86_cpuid(CPUX86State *env, uint32_t index, uint32_t count,
         break;
     case 0x80000000:
         *eax = env->cpuid_xlevel;
-        *ebx = env->cpuid_vendor1;
-        *edx = env->cpuid_vendor2;
-        *ecx = env->cpuid_vendor3;
+        if (cpu->vendor_cpuid_only && IS_INTEL_CPU(env)) {
+            *ebx = *ecx = *edx = 0;
+        } else {
+            *ebx = env->cpuid_vendor1;
+            *edx = env->cpuid_vendor2;
+            *ecx = env->cpuid_vendor3;
+        }
         break;
     case 0x80000001:
-        *eax = env->cpuid_version;
+        *eax = (cpu->vendor_cpuid_only && IS_INTEL_CPU(env)) ? 0 : env->cpuid_version;
         *ebx = 0;
         *ecx = env->features[FEAT_8000_0001_ECX];
         *edx = env->features[FEAT_8000_0001_EDX];