From 2560f19f426aceb4f2e809d860b93e7573cb1c4e Mon Sep 17 00:00:00 2001
From: Paolo Bonzini <pbonzini@redhat.com>
Date: Wed, 2 Oct 2013 17:54:57 +0200
Subject: [PATCH] x86: cpuid: reconstruct leaf 0Dh data

The data in leaf 0Dh depends on information from other feature bits.
Instead of passing it blindly from the host, compute it based on
whether these feature bits are enabled.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
---
 target-i386/cpu.c | 65 ++++++++++++++++++++++++++++++++++-------------
 1 file changed, 48 insertions(+), 17 deletions(-)

diff --git a/target-i386/cpu.c b/target-i386/cpu.c
index ea99b2692d..7c2584c8a1 100644
--- a/target-i386/cpu.c
+++ b/target-i386/cpu.c
@@ -328,6 +328,15 @@ X86RegisterInfo32 x86_reg_info_32[CPU_NB_REGS32] = {
 };
 #undef REGISTER
 
+typedef struct ExtSaveArea {
+    uint32_t feature, bits;
+    uint32_t offset, size;
+} ExtSaveArea;
+
+static const ExtSaveArea ext_save_areas[] = {
+    [2] = { .feature = FEAT_1_ECX, .bits = CPUID_EXT_AVX,
+            .offset = 0x100, .size = 0x240 },
+};
 
 const char *get_register_name_32(unsigned int reg)
 {
@@ -2180,29 +2189,51 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, uint32_t count,
             *edx = 0;
         }
         break;
-    case 0xD:
+    case 0xD: {
+        KVMState *s = cs->kvm_state;
+        uint64_t kvm_mask;
+        int i;
+
         /* Processor Extended State */
-        if (!(env->features[FEAT_1_ECX] & CPUID_EXT_XSAVE)) {
-            *eax = 0;
-            *ebx = 0;
-            *ecx = 0;
-            *edx = 0;
+        *eax = 0;
+        *ebx = 0;
+        *ecx = 0;
+        *edx = 0;
+        if (!(env->features[FEAT_1_ECX] & CPUID_EXT_XSAVE) || !kvm_enabled()) {
             break;
         }
-        if (kvm_enabled()) {
-            KVMState *s = cs->kvm_state;
+        kvm_mask =
+            kvm_arch_get_supported_cpuid(s, 0xd, 0, R_EAX) |
+            ((uint64_t)kvm_arch_get_supported_cpuid(s, 0xd, 0, R_EDX) << 32);
 
-            *eax = kvm_arch_get_supported_cpuid(s, 0xd, count, R_EAX);
-            *ebx = kvm_arch_get_supported_cpuid(s, 0xd, count, R_EBX);
-            *ecx = kvm_arch_get_supported_cpuid(s, 0xd, count, R_ECX);
-            *edx = kvm_arch_get_supported_cpuid(s, 0xd, count, R_EDX);
-        } else {
-            *eax = 0;
-            *ebx = 0;
-            *ecx = 0;
-            *edx = 0;
+        if (count == 0) {
+            *ecx = 0x240;
+            for (i = 2; i < ARRAY_SIZE(ext_save_areas); i++) {
+                const ExtSaveArea *esa = &ext_save_areas[i];
+                if ((env->features[esa->feature] & esa->bits) == esa->bits &&
+                    (kvm_mask & (1 << i)) != 0) {
+                    if (i < 32) {
+                        *eax |= 1 << i;
+                    } else {
+                        *edx |= 1 << (i - 32);
+                    }
+                    *ecx = MAX(*ecx, esa->offset + esa->size);
+                }
+            }
+            *eax |= kvm_mask & (XSTATE_FP | XSTATE_SSE);
+            *ebx = *ecx;
+        } else if (count == 1) {
+            *eax = kvm_arch_get_supported_cpuid(s, 0xd, 1, R_EAX);
+        } else if (count < ARRAY_SIZE(ext_save_areas)) {
+            const ExtSaveArea *esa = &ext_save_areas[count];
+            if ((env->features[esa->feature] & esa->bits) == esa->bits &&
+                (kvm_mask & (1 << count)) != 0) {
+                *eax = esa->offset;
+                *ebx = esa->size;
+            }
         }
         break;
+    }
     case 0x80000000:
         *eax = env->cpuid_xlevel;
         *ebx = env->cpuid_vendor1;