kvm: Fix cpuid initialization (Jan Kiszka)

Fix (more or less) spurious guest boot failures due to corrupted cpuid
states. The reason was insufficient initialization of cpuid entries
before passing them to the kernel.

At this chance also fix improper entry pointer progression and simplify
the code a bit.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@7167 c046a42c-6fe2-441c-8c8c-71466251a162

1 files changed, 20 insertions, 40 deletions

diff --git a/target-i386/kvm.c b/target-i386/kvm.c
index 4f437c221b..2de8b81296 100644
--- a/target-i386/kvm.c
+++ b/target-i386/kvm.c
@@ -41,12 +41,11 @@ int kvm_arch_init_vcpu(CPUState *env)
         struct kvm_cpuid_entry2 entries[100];
     } __attribute__((packed)) cpuid_data;
     uint32_t limit, i, j, cpuid_i;
-    uint32_t eax, ebx, ecx, edx;
+    uint32_t unused;
 
     cpuid_i = 0;
 
-    cpu_x86_cpuid(env, 0, 0, &eax, &ebx, &ecx, &edx);
-    limit = eax;
+    cpu_x86_cpuid(env, 0, 0, &limit, &unused, &unused, &unused);
 
     for (i = 0; i <= limit; i++) {
         struct kvm_cpuid_entry2 *c = &cpuid_data.entries[cpuid_i++];
@@ -56,26 +55,17 @@ int kvm_arch_init_vcpu(CPUState *env)
             /* Keep reading function 2 till all the input is received */
             int times;
 
-            cpu_x86_cpuid(env, i, 0, &eax, &ebx, &ecx, &edx);
-            times = eax & 0xff;
-
             c->function = i;
-            c->flags |= KVM_CPUID_FLAG_STATEFUL_FUNC;
-            c->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT;
-            c->eax = eax;
-            c->ebx = ebx;
-            c->ecx = ecx;
-            c->edx = edx;
+            c->flags = KVM_CPUID_FLAG_STATEFUL_FUNC |
+                       KVM_CPUID_FLAG_STATE_READ_NEXT;
+            cpu_x86_cpuid(env, i, 0, &c->eax, &c->ebx, &c->ecx, &c->edx);
+            times = c->eax & 0xff;
 
             for (j = 1; j < times; ++j) {
-                cpu_x86_cpuid(env, i, 0, &eax, &ebx, &ecx, &edx);
+                c = &cpuid_data.entries[cpuid_i++];
                 c->function = i;
-                c->flags |= KVM_CPUID_FLAG_STATEFUL_FUNC;
-                c->eax = eax;
-                c->ebx = ebx;
-                c->ecx = ecx;
-                c->edx = edx;
-                c = &cpuid_data.entries[++cpuid_i];
+                c->flags = KVM_CPUID_FLAG_STATEFUL_FUNC;
+                cpu_x86_cpuid(env, i, 0, &c->eax, &c->ebx, &c->ecx, &c->edx);
             }
             break;
         }
@@ -83,46 +73,36 @@ int kvm_arch_init_vcpu(CPUState *env)
         case 0xb:
         case 0xd:
             for (j = 0; ; j++) {
-                cpu_x86_cpuid(env, i, j, &eax, &ebx, &ecx, &edx);
                 c->function = i;
                 c->flags = KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
                 c->index = j;
-                c->eax = eax;
-                c->ebx = ebx;
-                c->ecx = ecx;
-                c->edx = edx;
-                c = &cpuid_data.entries[++cpuid_i];
+                cpu_x86_cpuid(env, i, j, &c->eax, &c->ebx, &c->ecx, &c->edx);
 
-                if (i == 4 && eax == 0)
+                if (i == 4 && c->eax == 0)
                     break;
-                if (i == 0xb && !(ecx & 0xff00))
+                if (i == 0xb && !(c->ecx & 0xff00))
                     break;
-                if (i == 0xd && eax == 0)
+                if (i == 0xd && c->eax == 0)
                     break;
+
+                c = &cpuid_data.entries[cpuid_i++];
             }
             break;
         default:
-            cpu_x86_cpuid(env, i, 0, &eax, &ebx, &ecx, &edx);
             c->function = i;
-            c->eax = eax;
-            c->ebx = ebx;
-            c->ecx = ecx;
-            c->edx = edx;
+            c->flags = 0;
+            cpu_x86_cpuid(env, i, 0, &c->eax, &c->ebx, &c->ecx, &c->edx);
             break;
         }
     }
-    cpu_x86_cpuid(env, 0x80000000, 0, &eax, &ebx, &ecx, &edx);
-    limit = eax;
+    cpu_x86_cpuid(env, 0x80000000, 0, &limit, &unused, &unused, &unused);
 
     for (i = 0x80000000; i <= limit; i++) {
         struct kvm_cpuid_entry2 *c = &cpuid_data.entries[cpuid_i++];
 
-        cpu_x86_cpuid(env, i, 0, &eax, &ebx, &ecx, &edx);
         c->function = i;
-        c->eax = eax;
-        c->ebx = ebx;
-        c->ecx = ecx;
-        c->edx = edx;
+        c->flags = 0;
+        cpu_x86_cpuid(env, i, 0, &c->eax, &c->ebx, &c->ecx, &c->edx);
     }
 
     cpuid_data.cpuid.nent = cpuid_i;