[v2,1/2] Do not register kvmclock savevm section if kvmclock is disabled.

Commit Message

Glauber Costa Dec. 6, 2010, 2:03 p.m. UTC

None

Patch

diff --git a/cpus.c b/cpus.c
index a55c330..a24098e 100644
--- a/cpus.c
+++ b/cpus.c
@@ -97,6 +97,9 @@  void cpu_synchronize_all_post_init(void)
     for (cpu = first_cpu; cpu; cpu = cpu->next_cpu) {
         cpu_synchronize_post_init(cpu);
     }
+    if (kvm_enabled()) {
+        kvmclock_register_savevm();
+    }
 }
 
 int cpu_is_stopped(CPUState *env)
diff --git a/qemu-kvm-x86.c b/qemu-kvm-x86.c
index 20b7d6d..14a52ce 100644
--- a/qemu-kvm-x86.c
+++ b/qemu-kvm-x86.c
@@ -504,6 +504,9 @@  static void kvmclock_pre_save(void *opaque)
 {
     struct kvm_clock_data *cl = opaque;
 
+    if (!kvmclock_enabled)
+        return;
+
     kvm_vm_ioctl(kvm_state, KVM_GET_CLOCK, cl);
 }
 
@@ -528,6 +531,16 @@  static const VMStateDescription vmstate_kvmclock= {
 };
 #endif
 
+/* This has to happen after vcpu setup*/
+void kvmclock_register_savevm(void)
+{
+#ifdef KVM_CAP_ADJUST_CLOCK
+    if (kvmclock_enabled && kvm_check_extension(kvm_state, KVM_CAP_ADJUST_CLOCK)) {
+        vmstate_register(NULL, 0, &vmstate_kvmclock, &kvmclock_data);
+    }
+#endif
+}
+
 int kvm_arch_qemu_create_context(void)
 {
     int r;
@@ -545,12 +558,6 @@  int kvm_arch_qemu_create_context(void)
         return -1;
     }
 
-#ifdef KVM_CAP_ADJUST_CLOCK
-    if (kvm_check_extension(kvm_state, KVM_CAP_ADJUST_CLOCK)) {
-        vmstate_register(NULL, 0, &vmstate_kvmclock, &kvmclock_data);
-    }
-#endif
-
     r = kvm_set_boot_cpu_id(0);
     if (r < 0 && r != -ENOSYS) {
         return r;
diff --git a/qemu-kvm.h b/qemu-kvm.h
index 0f3fb50..0a104ef 100644
--- a/qemu-kvm.h
+++ b/qemu-kvm.h
@@ -752,6 +752,9 @@  int handle_tpr_access(void *opaque, CPUState *env, uint64_t rip,
 #define qemu_kvm_cpu_stop(env) do {} while(0)
 #endif
 
+extern int kvmclock_enabled;
+void kvmclock_register_savevm(void);
+
 #ifdef CONFIG_KVM
 
 typedef struct KVMSlot {
diff --git a/target-i386/kvm.c b/target-i386/kvm.c
index 95e5d02..5443765 100644
--- a/target-i386/kvm.c
+++ b/target-i386/kvm.c
@@ -293,6 +293,7 @@  void kvm_inject_x86_mce(CPUState *cenv, int bank, uint64_t status,
 }
 
 static int _kvm_arch_init_vcpu(CPUState *env);
+int kvmclock_enabled = 1;
 
 int kvm_arch_init_vcpu(CPUState *env)
 {
@@ -350,6 +351,12 @@  int kvm_arch_init_vcpu(CPUState *env)
     memset(c, 0, sizeof(*c));
     c->function = KVM_CPUID_FEATURES;
     c->eax = env->cpuid_kvm_features & get_para_features(env);
+
+    if (!(c->eax & (1 << KVM_FEATURE_CLOCKSOURCE))) {
+        /* In theory cpuid is per-cpu, and this is a global variable,
+         * but we don't expect kvmclock enabled in some cpus only */
+        kvmclock_enabled = 0;
+    }
 #endif
 
     cpu_x86_cpuid(env, 0, 0, &limit, &unused, &unused, &unused);