Merge remote-tracking branch 'qemu-kvm/uq/master' into staging

# By Paolo Bonzini (2) and Jan Kiszka (1)
# Via Gleb Natapov
* qemu-kvm/uq/master:
  kvmvapic: Prevent reading beyond the end of guest RAM
  x86: cpuid: reconstruct leaf 0Dh data
  x86: fix migration from pre-version 12

Message-id: 1382108641-4862-1-git-send-email-pbonzini@redhat.com
Signed-off-by: Anthony Liguori <aliguori@amazon.com>

3 files changed, 56 insertions, 17 deletions

diff --git a/hw/i386/kvmvapic.c b/hw/i386/kvmvapic.c
index 1c2dbf59cf..2d876009fc 100644
--- a/hw/i386/kvmvapic.c
+++ b/hw/i386/kvmvapic.c
@@ -596,6 +596,9 @@ static int vapic_map_rom_writable(VAPICROMState *s)
     section = memory_region_find(as, 0, 1);
 
     /* read ROM size from RAM region */
+    if (rom_paddr + 2 >= memory_region_size(section.mr)) {
+        return -1;
+    }
     ram = memory_region_get_ram_ptr(section.mr);
     rom_size = ram[rom_paddr + 2] * ROM_BLOCK_SIZE;
     if (rom_size == 0) {
diff --git a/target-i386/cpu.c b/target-i386/cpu.c
index d0c9bdb629..864c80eb47 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)
 {
@@ -2177,29 +2186,51 @@ 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;
@@ -2402,6 +2433,7 @@ static void x86_cpu_reset(CPUState *s)
     env->fpuc = 0x37f;
 
     env->mxcsr = 0x1f80;
+    env->xstate_bv = XSTATE_FP | XSTATE_SSE;
 
     env->pat = 0x0007040600070406ULL;
     env->msr_ia32_misc_enable = MSR_IA32_MISC_ENABLE_DEFAULT;
diff --git a/target-i386/cpu.h b/target-i386/cpu.h
index 5723eff9a8..ea373e82dc 100644
--- a/target-i386/cpu.h
+++ b/target-i386/cpu.h
@@ -380,6 +380,10 @@
 
 #define MSR_VM_HSAVE_PA                 0xc0010117
 
+#define XSTATE_FP                       1
+#define XSTATE_SSE                      2
+#define XSTATE_YMM                      4
+
 /* CPUID feature words */
 typedef enum FeatureWord {
     FEAT_1_EDX,         /* CPUID[1].EDX */