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[Qemu-devel] [PATCH v2 11/21] cpuid: propagate further CPUID leafs when

Subject: [Qemu-devel] [PATCH v2 11/21] cpuid: propagate further CPUID leafs when -cpu host
From: Andre Przywara
Date: Fri, 18 Sep 2009 13:48:04 +0200
-cpu host currently only propagates the CPU's family/model/stepping,
the brand name and the feature bits.
Add a whitelist of safe CPUID leafs to let the guest see the actual
CPU's cache details and other things.

Signed-off-by: Andre Przywara <andre.przywara@xxxxxxx>
---
 target-i386/cpu.h   |    5 ++++-
 target-i386/cpuid.c |   28 ++++++++++++++++++++++------
 2 files changed, 26 insertions(+), 7 deletions(-)

diff --git a/target-i386/cpu.h b/target-i386/cpu.h
index b71d440..0f00d6a 100644
--- a/target-i386/cpu.h
+++ b/target-i386/cpu.h
@@ -563,6 +563,9 @@ typedef union {
 
 #define NB_MMU_MODES 2
 
+#define CPUID_FLAGS_VENDOR_OVERRIDE 1
+#define CPUID_FLAGS_HOST 2
+
 typedef struct CPUX86State {
     /* standard registers */
     target_ulong regs[CPU_NB_REGS];
@@ -672,7 +675,7 @@ typedef struct CPUX86State {
     uint32_t cpuid_ext2_features;
     uint32_t cpuid_ext3_features;
     uint32_t cpuid_apic_id;
-    int cpuid_vendor_override;
+    uint32_t cpuid_flags;
 
     /* MTRRs */
     uint64_t mtrr_fixed[11];
diff --git a/target-i386/cpuid.c b/target-i386/cpuid.c
index 9fdaa6c..4f2b359 100644
--- a/target-i386/cpuid.c
+++ b/target-i386/cpuid.c
@@ -115,7 +115,7 @@ typedef struct x86_def_t {
     uint32_t features, ext_features, ext2_features, ext3_features;
     uint32_t xlevel;
     char model_id[48];
-    int vendor_override;
+    uint32_t flags;
 } x86_def_t;
 
 #define I486_FEATURES (CPUID_FP87 | CPUID_VME | CPUID_PSE)
@@ -411,7 +411,7 @@ static int cpu_x86_fill_host(x86_def_t *x86_cpu_def)
     x86_cpu_def->ext2_features = edx;
     x86_cpu_def->ext3_features = ecx;
     cpu_x86_fill_model_id(x86_cpu_def->model_id);
-    x86_cpu_def->vendor_override = 0;
+    x86_cpu_def->flags = CPUID_FLAGS_HOST;
 
     return 0;
 }
@@ -516,7 +516,7 @@ static int cpu_x86_find_by_name(x86_def_t *x86_cpu_def, 
const char *cpu_model)
                     x86_cpu_def->vendor2 |= ((uint8_t)val[i + 4]) << (8 * i);
                     x86_cpu_def->vendor3 |= ((uint8_t)val[i + 8]) << (8 * i);
                 }
-                x86_cpu_def->vendor_override = 1;
+                x86_cpu_def->flags |= CPUID_FLAGS_VENDOR_OVERRIDE;
             } else if (!strcmp(featurestr, "model_id")) {
                 pstrcpy(x86_cpu_def->model_id, sizeof(x86_cpu_def->model_id),
                         val);
@@ -584,7 +584,7 @@ int cpu_x86_register (CPUX86State *env, const char 
*cpu_model)
         env->cpuid_vendor2 = CPUID_VENDOR_INTEL_2;
         env->cpuid_vendor3 = CPUID_VENDOR_INTEL_3;
     }
-    env->cpuid_vendor_override = def->vendor_override;
+    env->cpuid_flags = def->flags;
     env->cpuid_level = def->level;
     if (def->family > 0x0f)
         env->cpuid_version = 0xf00 | ((def->family - 0x0f) << 20);
@@ -615,17 +615,32 @@ int cpu_x86_register (CPUX86State *env, const char 
*cpu_model)
     return 0;
 }
 
+#define CPUID_LEAF_PROPAGATE ((1 << 0x02) | (1 << 0x04) | (1 << 0x05) |\
+                             (1 << 0x0D))
+#define CPUID_LEAF_PROPAGATE_EXTENDED ((1 << 0x05) | (1 << 0x06) |\
+                                      (1 << 0x08) | (1 << 0x19) | (1 << 0x1A))
+
 void cpu_x86_cpuid(CPUX86State *env, uint32_t index, uint32_t count,
                    uint32_t *eax, uint32_t *ebx,
                    uint32_t *ecx, uint32_t *edx)
 {
-    /* test if maximum index reached */
     if (index & 0x80000000) {
+    /* test if maximum index reached */
         if (index > env->cpuid_xlevel)
             index = env->cpuid_level;
+        if ((env->cpuid_flags & CPUID_FLAGS_HOST) &&
+            ((1 << (index - 0x80000000)) & CPUID_LEAF_PROPAGATE_EXTENDED)) {
+            host_cpuid(index, count, eax, ebx, ecx, edx);
+            return;
+        }
     } else {
         if (index > env->cpuid_level)
             index = env->cpuid_level;
+        if ((env->cpuid_flags & CPUID_FLAGS_HOST) &&
+            ((1 << index) & CPUID_LEAF_PROPAGATE)) {
+            host_cpuid(index, count, eax, ebx, ecx, edx);
+            return;
+        }
     }
 
     switch(index) {
@@ -641,7 +656,8 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, 
uint32_t count,
          * this if you want to use KVM's sysenter/syscall emulation
          * in compatibility mode and when doing cross vendor migration
          */
-        if (kvm_enabled() && !env->cpuid_vendor_override)
+        if (kvm_enabled() && 
+            (env->cpuid_flags & CPUID_FLAGS_VENDOR_OVERRIDE) == 0)
             host_cpuid(0, 0, NULL, ebx, ecx, edx);
         break;
     case 1:
-- 
1.6.1.3




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