[Qemu-devel] [PATCH 4/4] kvm pv features PART I

[Glauber Costa <glommer@redhat.com>]

Signed-off-by: Glauber Costa <glommer@redhat.com>
---
 kvm.h                |    5 +++++
 target-i386/helper.c |   19 ++++++++++++++++++-
 target-i386/kvm.c    |   30 ++++++++++++++++++++++++++++++
 3 files changed, 53 insertions(+), 1 deletions(-)

diff --git a/kvm.h b/kvm.h
index efce145..49a2653 100644
--- a/kvm.h
+++ b/kvm.h
@@ -17,6 +17,8 @@
 #include "config.h"
 
 #ifdef CONFIG_KVM
+#include <linux/kvm.h>
+#include <linux/kvm_para.h>
 extern int kvm_allowed;
 
 #define kvm_enabled() (kvm_allowed)
@@ -76,4 +78,7 @@ int kvm_arch_init(KVMState *s, int smp_cpus);
 
 int kvm_arch_init_vcpu(CPUState *env);
 
+/* x86 specific */
+uint32_t kvm_get_para_features(CPUState *env);
+
 #endif
diff --git a/target-i386/helper.c b/target-i386/helper.c
index 1410002..6bcd94d 100644
--- a/target-i386/helper.c
+++ b/target-i386/helper.c
@@ -1405,7 +1405,10 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index,
                    uint32_t *ecx, uint32_t *edx)
 {
     /* test if maximum index reached */
-    if (index & 0x80000000) {
+    if (index & 0x40000000) {
+        /* Those are KVM-specific, dodge them without messing with
+         * exposed cpuid_level */
+    } else if (index & 0x80000000) {
         if (index > env->cpuid_xlevel)
             index = env->cpuid_level;
     } else {
@@ -1511,6 +1514,20 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index,
         *ecx = 0;
         *edx = 0;
         break;
+    case 0x40000000:
+        if (kvm_enabled()) {
+            /* KVM CPUID signature */
+            *eax = 0;
+            *ebx = 0x4b4d564b; /* KVMKVMK */
+            *ecx = 0x564b4d56; /* VMKV */
+            *edx = 0x0000004d; /* M */
+        }
+        break;
+    case 0x40000001:
+        if (kvm_enabled()) {
+            *eax = kvm_get_para_features(env);
+        }
+        break;
     case 0x80000000:
         *eax = env->cpuid_xlevel;
         *ebx = env->cpuid_vendor1;
diff --git a/target-i386/kvm.c b/target-i386/kvm.c
index 64b24db..c9f0272 100644
--- a/target-i386/kvm.c
+++ b/target-i386/kvm.c
@@ -56,6 +56,36 @@ static void kvm_fill_cpuid(CPUState *env, KVMCpuid *cpuid_data,
     }
 }
 
+static struct kvm_para_features {
+    int cap;
+    int feature;
+} para_features[] = {
+#ifdef KVM_CAP_CLOCKSOURCE
+       { KVM_CAP_CLOCKSOURCE, KVM_FEATURE_CLOCKSOURCE },
+#endif
+#ifdef KVM_CAP_NOP_IO_DELAY
+       { KVM_CAP_NOP_IO_DELAY, KVM_FEATURE_NOP_IO_DELAY },
+#endif
+#ifdef KVM_CAP_PV_MMU
+       { KVM_CAP_PV_MMU, KVM_FEATURE_MMU_OP },
+#endif
+#ifdef KVM_CAP_CR3_CACHE
+       { KVM_CAP_CR3_CACHE, KVM_FEATURE_CR3_CACHE },
+#endif
+};
+
+uint32_t kvm_get_para_features(CPUState *env)
+ {
+    uint32_t i, features = 0;
+
+    for (i = 0; i < ARRAY_SIZE(para_features); i++) {
+        if (kvm_ioctl(env->kvm_state, KVM_CHECK_EXTENSION, para_features[i].cap))
+            features |= (1 << para_features[i].feature);
+    }
+
+    return features;
+}
+
 int kvm_arch_init_vcpu(CPUState *env)
 {
     KVMCpuid cpuid_data;
-- 
1.5.6.5