[PATCH] Add support for async page fault to qemu

[Gleb Natapov <gleb@redhat.com>]

Add save/restore of MSR for migration and cpuid bit.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
diff --git a/qemu-kvm-x86.c b/qemu-kvm-x86.c
index bb09fd8..5d8c428 100644
--- a/qemu-kvm-x86.c
+++ b/qemu-kvm-x86.c
@@ -678,6 +678,9 @@ static int get_msr_entry(struct kvm_msr_entry *entry, CPUState *env)
         env->mcg_ctl = entry->data;
         break;
 #endif
+    case MSR_KVM_ASYNC_PF_EN:
+        env->async_pf_en_msr = entry->data;
+        break;
     default:
 #ifdef KVM_CAP_MCE
         if (entry->index >= MSR_MC0_CTL &&
@@ -967,6 +970,7 @@ void kvm_arch_load_regs(CPUState *env, int level)
         }
         kvm_msr_entry_set(&msrs[n++], MSR_KVM_SYSTEM_TIME, env->system_time_msr);
         kvm_msr_entry_set(&msrs[n++], MSR_KVM_WALL_CLOCK, env->wall_clock_msr);
+        kvm_msr_entry_set(&msrs[n++], MSR_KVM_ASYNC_PF_EN, env->async_pf_en_msr);
     }
 #ifdef KVM_CAP_MCE
     if (env->mcg_cap) {
@@ -1186,6 +1190,7 @@ void kvm_arch_save_regs(CPUState *env)
 #endif
     msrs[n++].index = MSR_KVM_SYSTEM_TIME;
     msrs[n++].index = MSR_KVM_WALL_CLOCK;
+    msrs[n++].index = MSR_KVM_ASYNC_PF_EN;
 
 #ifdef KVM_CAP_MCE
     if (env->mcg_cap) {
diff --git a/target-i386/cpu.h b/target-i386/cpu.h
index 8b6efed..154b76b 100644
--- a/target-i386/cpu.h
+++ b/target-i386/cpu.h
@@ -669,6 +669,7 @@ typedef struct CPUX86State {
 #endif
     uint64_t system_time_msr;
     uint64_t wall_clock_msr;
+    uint64_t async_pf_en_msr;
 
     uint64_t tsc;
 
@@ -923,7 +924,7 @@ CPUState *pc_new_cpu(const char *cpu_model);
 #define cpu_list_id x86_cpu_list
 #define cpudef_setup	x86_cpudef_setup
 
-#define CPU_SAVE_VERSION 12
+#define CPU_SAVE_VERSION 13
 
 /* MMU modes definitions */
 #define MMU_MODE0_SUFFIX _kernel
diff --git a/target-i386/cpuid.c b/target-i386/cpuid.c
index d63fdcb..0ee1f88 100644
--- a/target-i386/cpuid.c
+++ b/target-i386/cpuid.c
@@ -73,7 +73,7 @@ static const char *ext3_feature_name[] = {
 };
 
 static const char *kvm_feature_name[] = {
-    "kvmclock", "kvm_nopiodelay", "kvm_mmu", NULL, NULL, NULL, NULL, NULL,
+    "kvmclock", "kvm_nopiodelay", "kvm_mmu", NULL, "kvm_asyncpf", NULL, NULL, NULL,
     NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL,
     NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL,
     NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL,
diff --git a/target-i386/kvm.c b/target-i386/kvm.c
index f4fc063..0eb1e90 100644
--- a/target-i386/kvm.c
+++ b/target-i386/kvm.c
@@ -151,6 +151,9 @@ struct kvm_para_features {
 #ifdef KVM_CAP_PV_MMU
         { KVM_CAP_PV_MMU, KVM_FEATURE_MMU_OP },
 #endif
+#ifdef KVM_CAP_ASYNC_PF
+        { KVM_CAP_ASYNC_PF, KVM_FEATURE_ASYNC_PF },
+#endif
         { -1, -1 }
 };
 
@@ -672,6 +675,7 @@ static int kvm_put_msrs(CPUState *env, int level)
         kvm_msr_entry_set(&msrs[n++], MSR_KVM_SYSTEM_TIME,
                           env->system_time_msr);
         kvm_msr_entry_set(&msrs[n++], MSR_KVM_WALL_CLOCK, env->wall_clock_msr);
+        kvm_msr_entry_set(&msrs[n++], MSR_KVM_ASYNC_PF_EN, env->async_pf_en_msr);
     }
 
     msr_data.info.nmsrs = n;
@@ -880,6 +884,7 @@ static int kvm_get_msrs(CPUState *env)
 #endif
     msrs[n++].index = MSR_KVM_SYSTEM_TIME;
     msrs[n++].index = MSR_KVM_WALL_CLOCK;
+    msrs[n++].index = MSR_KVM_ASYNC_PF_EN;
 
     msr_data.info.nmsrs = n;
     ret = kvm_vcpu_ioctl(env, KVM_GET_MSRS, &msr_data);
@@ -926,6 +931,9 @@ static int kvm_get_msrs(CPUState *env)
         case MSR_VM_HSAVE_PA:
             env->vm_hsave = msrs[i].data;
             break;
+	case MSR_KVM_ASYNC_PF_EN:
+            env->async_pf_en_msr = msrs[i].data;
+            break;
         }
     }
 
diff --git a/target-i386/machine.c b/target-i386/machine.c
index 4398801..092c901 100644
--- a/target-i386/machine.c
+++ b/target-i386/machine.c
@@ -474,6 +474,9 @@ static const VMStateDescription vmstate_cpu = {
         VMSTATE_UINT64_V(xcr0, CPUState, 12),
         VMSTATE_UINT64_V(xstate_bv, CPUState, 12),
         VMSTATE_YMMH_REGS_VARS(ymmh_regs, CPUState, CPU_NB_REGS, 12),
+
+	/* KVM async pf msr */
+        VMSTATE_UINT64_V(async_pf_en_msr, CPUState, 13),
         VMSTATE_END_OF_LIST()
         /* The above list is not sorted /wrt version numbers, watch out! */
     }
--
			Gleb.