[Qemu-devel] [PATCH] qemu-kvm: Add CPUID support for VIA CPU

[<BrillyWu@viatech.com.cn>]

When KVM is running on VIA CPU with host cpu's model, the feautures of
VIA CPU will be passed into kvm guest by calling the CPUID instruction
for Centaur.

Signed-off-by: BrillyWu<brillywu@viatech.com.cn>
Signed-off-by: KaryJin<karyjin@viatech.com.cn>
---
 target-i386/cpu.h   |    7 +++++++
 target-i386/cpuid.c |   48
+++++++++++++++++++++++++++++++++++++++++++++++-
 target-i386/kvm.c   |   15 +++++++++++++++
 3 files changed, 69 insertions(+), 1 deletion(-)

--- a/target-i386/cpu.h	2011-05-05 09:01:11.742328398 +0800
+++ b/target-i386/cpu.h	2011-05-05 10:47:32.112329696 +0800
@@ -441,6 +441,10 @@
 #define CPUID_VENDOR_AMD_2   0x69746e65 /* "enti" */ 
 #define CPUID_VENDOR_AMD_3   0x444d4163 /* "cAMD" */
 
+#define CPUID_VENDOR_VIA_1   0x746e6543 /* "Cent" */
+#define CPUID_VENDOR_VIA_2   0x48727561 /* "aurH" */
+#define CPUID_VENDOR_VIA_3   0x736c7561 /* "auls" */
+
 #define CPUID_MWAIT_IBE     (1 << 1) /* Interrupts can exit capability
*/
 #define CPUID_MWAIT_EMX     (1 << 0) /* enumeration supported */
 
@@ -721,6 +725,9 @@ typedef struct CPUX86State {
     uint32_t cpuid_ext3_features;
     uint32_t cpuid_apic_id;
     int cpuid_vendor_override;
+    /*Store the results of Centaur's CPUID instructions*/
+    uint32_t cpuid_xlevel2;
+    uint32_t cpuid_ext4_features;
 
     /* MTRRs */
     uint64_t mtrr_fixed[11];
--- a/target-i386/cpuid.c	2011-05-05 09:01:05.352331142 +0800
+++ b/target-i386/cpuid.c	2011-05-05 10:47:41.102330705 +0800
@@ -230,6 +230,9 @@ typedef struct x86_def_t {
     char model_id[48];
     int vendor_override;
     uint32_t flags;
+    /*Store the results of Centaur's CPUID instructions*/
+    uint32_t ext4_features;
+    uint32_t xlevel2;
 } x86_def_t;
 
 #define I486_FEATURES (CPUID_FP87 | CPUID_VME | CPUID_PSE) @@ -522,6
+525,17 @@ static int cpu_x86_fill_host(x86_def_t *
     cpu_x86_fill_model_id(x86_cpu_def->model_id);
     x86_cpu_def->vendor_override = 0;
 
+    /* Call Centaur's CPUID instruction. */
+    if (x86_cpu_def->vendor1 == CPUID_VENDOR_VIA_1 &&
+	x86_cpu_def->vendor2 == CPUID_VENDOR_VIA_2 &&
+	x86_cpu_def->vendor3 == CPUID_VENDOR_VIA_3) {
+	    host_cpuid(0xC0000000, 0, &eax, &ebx, &ecx, &edx);
+	    if (eax >= 0xC0000001) {
+		x86_cpu_def->xlevel2 = eax; /*support VIA max extended
level*/
+		host_cpuid(0xC0000001, 0, &eax, &ebx, &ecx, &edx);
+		x86_cpu_def->ext4_features = edx;
+	    }
+    }
 
     /*
      * Every SVM feature requires emulation support in KVM - so we
can't just @@ -855,6 +869,8 @@ int cpu_x86_register (CPUX86State *env,
     env->cpuid_xlevel = def->xlevel;
     env->cpuid_kvm_features = def->kvm_features;
     env->cpuid_svm_features = def->svm_features;
+    env->cpuid_ext4_features = def->ext4_features;
+    env->cpuid_xlevel2 = def->xlevel2;
     if (!kvm_enabled()) {
         env->cpuid_features &= TCG_FEATURES;
         env->cpuid_ext_features &= TCG_EXT_FEATURES; @@ -1034,7
+1050,15 @@ void cpu_x86_cpuid(CPUX86State *env, uin
                    uint32_t *ecx, uint32_t *edx)  {
     /* test if maximum index reached */
-    if (index & 0x80000000) {
+    if ((index & 0xC0000000) == 0xC0000000) {
+	/* Handle the Centaur's CPUID instruction.*
+	* If cpuid_xlevel2 is "0", then put into the*
+	* default case. */
+	if (env->cpuid_xlevel2 == 0)
+	    index = 0xF0000000;
+	else if (index > env->cpuid_xlevel2)
+	    index = env->cpuid_xlevel2;
+    } else if (index & 0x80000000) {
         if (index > env->cpuid_xlevel)
             index = env->cpuid_level;
     } else {
@@ -1256,6 +1280,28 @@ void cpu_x86_cpuid(CPUX86State *env, uin
 		*edx = 0;
 	}
         break;
+    case 0xC0000000:
+	*eax = env->cpuid_xlevel2;
+	*ebx = 0;
+	*ecx = 0;
+	*edx = 0;
+	break;
+    case 0xC0000001:
+	/* Support for VIA CPU's CPUID instruction */
+	*eax = env->cpuid_version;
+	*ebx = 0;
+	*ecx = 0;
+	*edx = env->cpuid_ext4_features;
+	break;
+    case 0xC0000002:
+    case 0xC0000003:
+    case 0xC0000004:
+	/*Reserved for the future, and now filled with zero*/
+	*eax = 0;
+	*ebx = 0;
+	*ecx = 0;
+	*edx = 0;
+	break;
     default:
         /* reserved values: zero */
         *eax = 0;
--- a/target-i386/kvm.c	2011-05-05 09:01:17.182326246 +0800
+++ b/target-i386/kvm.c	2011-05-05 10:47:48.312331989 +0800
@@ -496,6 +496,21 @@ int kvm_arch_init_vcpu(CPUState *env)
         cpu_x86_cpuid(env, i, 0, &c->eax, &c->ebx, &c->ecx, &c->edx);
     }
 
+    /* Call Centaur's CPUID instructions they are supported. */
+    if (env->cpuid_xlevel2 > 0) {
+	env->cpuid_ext4_features &=
+		kvm_arch_get_supported_cpuid(env, 0xC0000001, 0, R_EDX);
+	cpu_x86_cpuid(env, 0xC0000000, 0, &limit, &unused, &unused,
&unused);
+
+	for (i = 0xC0000000; i <= limit; i++) {
+	    c = &cpuid_data.entries[cpuid_i++];
+
+	    c->function = i;
+	    c->flags = 0;
+	    cpu_x86_cpuid(env, i, 0, &c->eax, &c->ebx, &c->ecx,
&c->edx);
+	}
+    }
+
     cpuid_data.cpuid.nent = cpuid_i;
 
 #ifdef KVM_CAP_MCE