[Qemu-devel] [PATCH 11/12] cpuid: add TCG feature bit trimming

[Andre Przywara]

In KVM we trim the user provided CPUID bits to match the host CPU's
one. Introduce a similar feature to QEMU/TCG. Create a mask of TCG's
capabilities and apply it to the user bits.
This allows to let the CPU models reflect their native archetypes.
(which will be send in a later patch).

Signed-off-by: Andre Przywara <address@hidden>
---
 target-i386/cpuid.c |   27 ++++++++++++++++++++++++---
 1 files changed, 24 insertions(+), 3 deletions(-)

diff --git a/target-i386/cpuid.c b/target-i386/cpuid.c
index ca8fc45..b35523c 100644
--- a/target-i386/cpuid.c
+++ b/target-i386/cpuid.c
@@ -118,6 +118,19 @@ typedef struct x86_def_t {
           CPUID_PAE | CPUID_SEP | CPUID_APIC)
 #define EXT2_FEATURE_MASK 0x0183F3FF
 
+#define TCG_FEATURES (CPUID_FP87 | CPUID_PSE | CPUID_TSC | CPUID_MSR | \
+          CPUID_PAE | CPUID_MCE | CPUID_CX8 | CPUID_APIC | CPUID_SEP | \
+          CPUID_MTRR | CPUID_PGE | CPUID_MCA | CPUID_CMOV | CPUID_PAT | \
+          CPUID_PSE36 | CPUID_CLFLUSH | CPUID_ACPI | CPUID_MMX | \
+          CPUID_FXSR | CPUID_SSE | CPUID_SSE2 | CPUID_SS)
+#define TCG_EXT_FEATURES (CPUID_EXT_SSE3 | CPUID_EXT_MONITOR | \
+            CPUID_EXT_CX16 | CPUID_EXT_POPCNT | CPUID_EXT_XSAVE | \
+            CPUID_EXT_HYPERVISOR)
+#define TCG_EXT2_FEATURES ((TCG_FEATURES & EXT2_FEATURE_MASK) | \
+            CPUID_EXT2_NX | CPUID_EXT2_MMXEXT | CPUID_EXT2_3DNOW | \
+            CPUID_EXT2_3DNOWEXT)
+#define TCG_EXT3_FEATURES (CPUID_EXT3_LAHF_LM | CPUID_EXT3_SVM)
+
 static x86_def_t x86_defs[] = {
 #ifdef TARGET_X86_64
     {
@@ -588,6 +601,17 @@ int cpu_x86_register (CPUX86State *env, const char 
*cpu_model)
     env->cpuid_ext2_features = def->ext2_features;
     env->cpuid_xlevel = def->xlevel;
     env->cpuid_ext3_features = def->ext3_features;
+    if (!kvm_enabled()) {
+        env->cpuid_features &= TCG_FEATURES;
+        env->cpuid_ext_features &= TCG_EXT_FEATURES;
+        env->cpuid_ext2_features &= (TCG_EXT2_FEATURES
+#ifdef TARGET_X86_64
+                | CPUID_EXT2_SYSCALL | CPUID_EXT2_LM);
+#else
+                );
+#endif
+        env->cpuid_ext3_features &= TCG_EXT3_FEATURES;
+    }
     {
         const char *model_id = def->model_id;
         int c, len, i;
@@ -755,9 +779,6 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, 
uint32_t count,
         if (kvm_enabled()) {
             /* Nested SVM not yet supported in upstream QEMU */
             *ecx &= ~CPUID_EXT3_SVM;
-        } else {
-            /* AMD 3DNow! is not supported in QEMU */
-            *edx &= ~(CPUID_EXT2_3DNOW | CPUID_EXT2_3DNOWEXT);
         }
         break;
     case 0x80000002:
-- 
1.6.1.3