Add CPUState::stable_cpu_id and use that as instance_id in
vmstate_register() call.
Introduce has-stable_cpu_id property that allows target machines to
optionally switch to using stable_cpu_id instead of cpu_index.
This will help allow successful migration in cases where holes are
introduced in cpu_index range after CPU hot removals.
Suggested-by: Igor Mammedov <imamm...@redhat.com>
Signed-off-by: Bharata B Rao <bhar...@linux.vnet.ibm.com>
---
exec.c | 6 ++++--
include/qom/cpu.h | 5 +++++
qom/cpu.c | 6 ++++++
3 files changed, 15 insertions(+), 2 deletions(-)
diff --git a/exec.c b/exec.c
index fb73910..3b36fe5 100644
--- a/exec.c
+++ b/exec.c
@@ -619,12 +619,14 @@ static void cpu_release_index(CPUState *cpu)
void cpu_vmstate_register(CPUState *cpu)
{
CPUClass *cc = CPU_GET_CLASS(cpu);
+ int instance_id = cpu->has_stable_cpu_id ? cpu->stable_cpu_id :
+ cpu->cpu_index;
if (qdev_get_vmsd(DEVICE(cpu)) == NULL) {
- vmstate_register(NULL, cpu->cpu_index, &vmstate_cpu_common, cpu);
+ vmstate_register(NULL, instance_id, &vmstate_cpu_common, cpu);
}
if (cc->vmsd != NULL) {
- vmstate_register(NULL, cpu->cpu_index, cc->vmsd, cpu);
+ vmstate_register(NULL, instance_id, cc->vmsd, cpu);
}
}
diff --git a/include/qom/cpu.h b/include/qom/cpu.h
index 331386f..527c021 100644
--- a/include/qom/cpu.h
+++ b/include/qom/cpu.h
@@ -273,6 +273,9 @@ struct qemu_work_item {
* @kvm_fd: vCPU file descriptor for KVM.
* @work_mutex: Lock to prevent multiple access to queued_work_*.
* @queued_work_first: First asynchronous work pending.
+ * @stable_cpu_id: Use as instance_id argument in cpu vmstate_register calls
+ * @has_stable_cpu_id: Set to enforce the use of @stable_cpu_id
+ * over cpu_index during vmstate registration.
*
* State of one CPU core or thread.
*/
@@ -360,6 +363,8 @@ struct CPUState {
(absolute value) offset as small as possible. This reduces code
size, especially for hosts without large memory offsets. */
uint32_t tcg_exit_req;
+ int stable_cpu_id;
+ bool has_stable_cpu_id;
};
QTAILQ_HEAD(CPUTailQ, CPUState);
diff --git a/qom/cpu.c b/qom/cpu.c
index 1095ea1..bae1bf7 100644
--- a/qom/cpu.c
+++ b/qom/cpu.c
@@ -363,6 +363,11 @@ static int64_t cpu_common_get_arch_id(CPUState *cpu)
return cpu->cpu_index;
}
+static Property cpu_common_properties[] = {
+ DEFINE_PROP_BOOL("has-stable-cpu-id", CPUState, has_stable_cpu_id, false),
+ DEFINE_PROP_END_OF_LIST()
+};
+
static void cpu_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
@@ -394,6 +399,7 @@ static void cpu_class_init(ObjectClass *klass, void *data)
* IRQs, adding reset handlers, halting non-first CPUs, ...
*/
dc->cannot_instantiate_with_device_add_yet = true;
+ dc->props = cpu_common_properties;
}
static const TypeInfo cpu_type_info = {
--
2.7.4
