Hey,
This patch is a proposal only. Among other things, it relies on a patch
Juan is yet to send, and I also would want to give it a bit more testing.
It shows my indented use of the new ioctl interface I've been proposing.
First of all, we have to save the kvmclock msrs. This is per-cpu, and we
were failing to do it so far.
The ioctls are issued in pre-save and post-load sections of a new vmstate
handler. I am not doing it in the cpu vmstate handler, because this has to
be done once per VM, not cpu. What I basically do is to grab the time
from GET ioctl, pass on through migration, and then do a SET on the other
side. Should be straighforward.
Please let me hear your thoughts. And don't get me started with this
"you can't hear thoughts" thing!
Signed-off-by: Glauber Costa <glommer@xxxxxxxxxx>
---
kvm/include/linux/kvm.h | 9 +++++++++
qemu-kvm-x86.c | 6 ++++++
qemu-kvm.c | 29 +++++++++++++++++++++++++++++
target-i386/cpu.h | 3 ++-
target-i386/machine.c | 2 ++
5 files changed, 48 insertions(+), 1 deletions(-)
diff --git a/qemu-kvm-x86.c b/qemu-kvm-x86.c
index fffcfd8..75e2ffd 100644
--- a/qemu-kvm-x86.c
+++ b/qemu-kvm-x86.c
@@ -834,6 +834,9 @@ static int get_msr_entry(struct kvm_msr_entry *entry, CPUState *env)
case MSR_VM_HSAVE_PA:
env->vm_hsave = entry->data;
break;
+ case MSR_KVM_SYSTEM_TIME:
+ env->system_time_msr = entry->data;
+ break;
default:
printf("Warning unknown msr index 0x%x\n", entry->index);
return 1;
@@ -1001,6 +1004,7 @@ void kvm_arch_load_regs(CPUState *env)
set_msr_entry(&msrs[n++], MSR_LSTAR , env->lstar);
}
#endif
+ set_msr_entry(&msrs[n++], MSR_KVM_SYSTEM_TIME, env->system_time_msr);
rc = kvm_set_msrs(env->kvm_cpu_state.vcpu_ctx, msrs, n);
if (rc == -1)
@@ -1179,6 +1183,8 @@ void kvm_arch_save_regs(CPUState *env)
msrs[n++].index = MSR_LSTAR;
}
#endif
+ msrs[n++].index = MSR_KVM_SYSTEM_TIME;
+
rc = kvm_get_msrs(env->kvm_cpu_state.vcpu_ctx, msrs, n);
if (rc == -1) {
perror("kvm_get_msrs FAILED");
diff --git a/qemu-kvm.c b/qemu-kvm.c
index 87ece3d..75e9575 100644
--- a/qemu-kvm.c
+++ b/qemu-kvm.c
@@ -347,6 +347,34 @@ int kvm_dirty_pages_log_reset(kvm_context_t kvm)
static int kvm_create_context(void);
+static struct kvm_clock_data kvmclock_data;
+
+static void kvmclock_pre_save(void *opaque)
+{
+ struct kvm_clock_data *cl = opaque;
+
+ kvm_vm_ioctl(kvm_state, KVM_GET_CLOCK, cl);
+}
+
+static int kvmclock_post_load(void *opaque, int version_id)
+{
+ struct kvm_clock_data *cl = opaque;
+
+ return kvm_vm_ioctl(kvm_state, KVM_SET_CLOCK, cl);
+}
+
+static const VMStateDescription vmstate_kvmclock= {
+ .name = "timer",
+ .version_id = 1,
+ .minimum_version_id = 1,
+ .minimum_version_id_old = 1,
+ .pre_save = kvmclock_pre_save,
+ .post_load = kvmclock_post_load,
+ .fields = (VMStateField []) {
+ VMSTATE_U64(clock, struct kvm_clock_data),
+ VMSTATE_END_OF_LIST()
+ }
+};
int kvm_init(int smp_cpus)
{
@@ -406,6 +434,7 @@ int kvm_init(int smp_cpus)
set_gsi(kvm_context, i);
}
+ vmstate_register(0, &vmstate_kvmclock, &kvmclock_data);
pthread_mutex_lock(&qemu_mutex);
return kvm_create_context();
diff --git a/target-i386/cpu.h b/target-i386/cpu.h
index 278d3e3..8022772 100644
--- a/target-i386/cpu.h
+++ b/target-i386/cpu.h
@@ -667,6 +667,7 @@ typedef struct CPUX86State {
target_ulong fmask;
target_ulong kernelgsbase;
#endif
+ uint64_t system_time_msr;
uint64_t tsc;
@@ -886,7 +887,7 @@ uint64_t cpu_get_tsc(CPUX86State *env);
#define cpu_signal_handler cpu_x86_signal_handler
#define cpu_list x86_cpu_list
-#define CPU_SAVE_VERSION 11
+#define CPU_SAVE_VERSION 12
/* MMU modes definitions */
#define MMU_MODE0_SUFFIX _kernel
diff --git a/target-i386/machine.c b/target-i386/machine.c
index 16d9c57..d5267be 100644
--- a/target-i386/machine.c
+++ b/target-i386/machine.c
@@ -479,6 +479,8 @@ const VMStateDescription vmstate_cpu = {
VMSTATE_UINT64_ARRAY_V(mce_banks, CPUState, MCE_BANKS_DEF *4, 10),
/* rdtscp */
VMSTATE_UINT64_V(tsc_aux, CPUState, 11),
+ /* KVM pvclock msr */
+ VMSTATE_UINT64_V(system_time_msr, CPUState, 12),
VMSTATE_END_OF_LIST()
}
};
--
1.6.2.2
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