diff --git a/cutils.c b/cutils.c
index f9a7e3689e..28049e0699 100644
--- a/cutils.c
+++ b/cutils.c
@@ -322,7 +322,8 @@ int fcntl_setfl(int fd, int flag)
  * value must be terminated by whitespace, ',' or '\0'. Return -1 on
  * error.
  */
-int64_t strtosz_suffix(const char *nptr, char **end, const char default_suffix)
+int64_t strtosz_suffix_unit(const char *nptr, char **end,
+                            const char default_suffix, int64_t unit)
 {
     int64_t retval = -1;
     char *endptr;
@@ -362,20 +363,20 @@ int64_t strtosz_suffix(const char *nptr, char **end, const char default_suffix)
         }
         break;
     case STRTOSZ_DEFSUFFIX_KB:
-        mul = 1 << 10;
+        mul = unit;
         break;
     case 0:
         if (mul_required) {
             goto fail;
         }
     case STRTOSZ_DEFSUFFIX_MB:
-        mul = 1ULL << 20;
+        mul = unit * unit;
         break;
     case STRTOSZ_DEFSUFFIX_GB:
-        mul = 1ULL << 30;
+        mul = unit * unit * unit;
         break;
     case STRTOSZ_DEFSUFFIX_TB:
-        mul = 1ULL << 40;
+        mul = unit * unit * unit * unit;
         break;
     default:
         goto fail;
@@ -405,6 +406,11 @@ fail:
     return retval;
 }
 
+int64_t strtosz_suffix(const char *nptr, char **end, const char default_suffix)
+{
+        return strtosz_suffix_unit(nptr, end, default_suffix, 1024);
+}
+
 int64_t strtosz(const char *nptr, char **end)
 {
     return strtosz_suffix(nptr, end, STRTOSZ_DEFSUFFIX_MB);
diff --git a/hw/kvmclock.c b/hw/kvmclock.c
index 692ad182f0..b73aec409c 100644
--- a/hw/kvmclock.c
+++ b/hw/kvmclock.c
@@ -101,11 +101,8 @@ static SysBusDeviceInfo kvmclock_info = {
 void kvmclock_create(void)
 {
     if (kvm_enabled() &&
-        first_cpu->cpuid_kvm_features & ((1ULL << KVM_FEATURE_CLOCKSOURCE)
-#ifdef KVM_FEATURE_CLOCKSOURCE2
-        || (1ULL << KVM_FEATURE_CLOCKSOURCE2)
-#endif
-    )) {
+        first_cpu->cpuid_kvm_features & ((1ULL << KVM_FEATURE_CLOCKSOURCE) |
+                                         (1ULL << KVM_FEATURE_CLOCKSOURCE2))) {
         sysbus_create_simple("kvmclock", -1, NULL);
     }
 }
diff --git a/kvm-all.c b/kvm-all.c
index cbc253235e..b9c172b664 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -1328,7 +1328,6 @@ int kvm_set_signal_mask(CPUState *env, const sigset_t *sigset)
 
 int kvm_set_ioeventfd_mmio_long(int fd, uint32_t addr, uint32_t val, bool assign)
 {
-#ifdef KVM_IOEVENTFD
     int ret;
     struct kvm_ioeventfd iofd;
 
@@ -1353,14 +1352,10 @@ int kvm_set_ioeventfd_mmio_long(int fd, uint32_t addr, uint32_t val, bool assign
     }
 
     return 0;
-#else
-    return -ENOSYS;
-#endif
 }
 
 int kvm_set_ioeventfd_pio_word(int fd, uint16_t addr, uint16_t val, bool assign)
 {
-#ifdef KVM_IOEVENTFD
     struct kvm_ioeventfd kick = {
         .datamatch = val,
         .addr = addr,
@@ -1380,9 +1375,6 @@ int kvm_set_ioeventfd_pio_word(int fd, uint16_t addr, uint16_t val, bool assign)
         return r;
     }
     return 0;
-#else
-    return -ENOSYS;
-#endif
 }
 
 int kvm_on_sigbus_vcpu(CPUState *env, int code, void *addr)
diff --git a/qemu-common.h b/qemu-common.h
index 0fdecf1ede..74d5c4b962 100644
--- a/qemu-common.h
+++ b/qemu-common.h
@@ -157,6 +157,8 @@ int fcntl_setfl(int fd, int flag);
 #define STRTOSZ_DEFSUFFIX_B	'B'
 int64_t strtosz(const char *nptr, char **end);
 int64_t strtosz_suffix(const char *nptr, char **end, const char default_suffix);
+int64_t strtosz_suffix_unit(const char *nptr, char **end,
+                            const char default_suffix, int64_t unit);
 
 /* path.c */
 void init_paths(const char *prefix);
diff --git a/target-i386/cpu.h b/target-i386/cpu.h
index ae0e4b1438..4a6f675f98 100644
--- a/target-i386/cpu.h
+++ b/target-i386/cpu.h
@@ -743,6 +743,7 @@ typedef struct CPUX86State {
     uint32_t cpuid_kvm_features;
     uint32_t cpuid_svm_features;
     bool tsc_valid;
+    int tsc_khz;
     
     /* in order to simplify APIC support, we leave this pointer to the
        user */
diff --git a/target-i386/cpuid.c b/target-i386/cpuid.c
index e1ae3af1e3..89e9623859 100644
--- a/target-i386/cpuid.c
+++ b/target-i386/cpuid.c
@@ -224,6 +224,7 @@ typedef struct x86_def_t {
     int family;
     int model;
     int stepping;
+    int tsc_khz;
     uint32_t features, ext_features, ext2_features, ext3_features;
     uint32_t kvm_features, svm_features;
     uint32_t xlevel;
@@ -704,6 +705,17 @@ static int cpu_x86_find_by_name(x86_def_t *x86_cpu_def, const char *cpu_model)
             } else if (!strcmp(featurestr, "model_id")) {
                 pstrcpy(x86_cpu_def->model_id, sizeof(x86_cpu_def->model_id),
                         val);
+            } else if (!strcmp(featurestr, "tsc_freq")) {
+                int64_t tsc_freq;
+                char *err;
+
+                tsc_freq = strtosz_suffix_unit(val, &err,
+                                               STRTOSZ_DEFSUFFIX_B, 1000);
+                if (!*val || *err) {
+                    fprintf(stderr, "bad numerical value %s\n", val);
+                    goto error;
+                }
+                x86_cpu_def->tsc_khz = tsc_freq / 1000;
             } else {
                 fprintf(stderr, "unrecognized feature %s\n", featurestr);
                 goto error;
@@ -872,6 +884,7 @@ int cpu_x86_register (CPUX86State *env, const char *cpu_model)
     env->cpuid_svm_features = def->svm_features;
     env->cpuid_ext4_features = def->ext4_features;
     env->cpuid_xlevel2 = def->xlevel2;
+    env->tsc_khz = def->tsc_khz;
     if (!kvm_enabled()) {
         env->cpuid_features &= TCG_FEATURES;
         env->cpuid_ext_features &= TCG_EXT_FEATURES;
diff --git a/target-i386/kvm.c b/target-i386/kvm.c
index 10fb2c4b07..31b88b7499 100644
--- a/target-i386/kvm.c
+++ b/target-i386/kvm.c
@@ -354,6 +354,7 @@ int kvm_arch_init_vcpu(CPUState *env)
     uint32_t unused;
     struct kvm_cpuid_entry2 *c;
     uint32_t signature[3];
+    int r;
 
     env->cpuid_features &= kvm_arch_get_supported_cpuid(s, 1, 0, R_EDX);
 
@@ -499,7 +500,20 @@ int kvm_arch_init_vcpu(CPUState *env)
 
     qemu_add_vm_change_state_handler(cpu_update_state, env);
 
-    return kvm_vcpu_ioctl(env, KVM_SET_CPUID2, &cpuid_data);
+    r = kvm_vcpu_ioctl(env, KVM_SET_CPUID2, &cpuid_data);
+    if (r)
+	    return r;
+
+    r = kvm_check_extension(env->kvm_state, KVM_CAP_TSC_CONTROL);
+    if (r && env->tsc_khz) {
+        r = kvm_vcpu_ioctl(env, KVM_SET_TSC_KHZ, env->tsc_khz);
+        if (r < 0) {
+            fprintf(stderr, "KVM_SET_TSC_KHZ failed\n");
+            return r;
+        }
+    }
+
+    return 0;
 }
 
 void kvm_arch_reset_vcpu(CPUState *env)