On 11/02/2016 03:40 AM, Juan Quintela wrote:
> Jianjun Duan <du...@linux.vnet.ibm.com> wrote:
>> Current migration code cannot handle some data structures such as
>> QTAILQ in qemu/queue.h. Here we extend the signatures of put/get
>> in VMStateInfo so that customized handling is supported.
>>
>> Signed-off-by: Jianjun Duan <du...@linux.vnet.ibm.com>
>
>> +/* VMStateInfo allows customized migration of objects that don't fit in
>> + * any category in VMStateFlags. Additional information can be passed
>> + * into get and put in terms of field and vmdesc parameters.
>> + * For primitive data types such as integer, field and vmdesc parameters
>> + * should be ignored inside get/put. */
>> struct VMStateInfo {
>> const char *name;
>> - int (*get)(QEMUFile *f, void *pv, size_t size);
>> - void (*put)(QEMUFile *f, void *pv, size_t size);
>> + int (*get)(QEMUFile *f, void *pv, size_t size, VMStateField *field);
>> + void (*put)(QEMUFile *f, void *pv, size_t size, VMStateField *field,
>> + QJSON *vmdesc);
>
> If we are changing put type, I would like to add an error value to it.
>
so we change the return type to int?
>> static void vmstate_subsection_save(QEMUFile *f, const VMStateDescription
>> *vmsd,
>> void *opaque, QJSON *vmdesc);
>> @@ -83,6 +84,7 @@ int vmstate_load_state(QEMUFile *f, const
>> VMStateDescription *vmsd,
>>
>> trace_vmstate_load_state(vmsd->name, version_id);
>> if (version_id > vmsd->version_id) {
>> + error_report("%s %s", vmsd->name, "too new");
>> trace_vmstate_load_state_end(vmsd->name, "too new", -EINVAL);
>> return -EINVAL;
>> }
>> @@ -93,6 +95,7 @@ int vmstate_load_state(QEMUFile *f, const
>> VMStateDescription *vmsd,
>> trace_vmstate_load_state_end(vmsd->name, "old path", ret);
>> return ret;
>> }
>> + error_report("%s %s", vmsd->name, "too old");
>> trace_vmstate_load_state_end(vmsd->name, "too old", -EINVAL);
>> return -EINVAL;
>> }
>
> This two are good, but don't belong to this patch, please sent separately.
>
OK.
>> @@ -122,8 +125,10 @@ int vmstate_load_state(QEMUFile *f, const
>> VMStateDescription *vmsd,
>> ret = vmstate_load_state(f, field->vmsd, addr,
>> field->vmsd->version_id);
>> } else {
>> - ret = field->info->get(f, addr, size);
>> -
>> + /* field is always passed in. But it should be ignored
>> by
>> + * get when not needed. It is only needed in cases* of
>> + * customized handling, such as migrating QTAILQ. */
>> + ret = field->info->get(f, addr, size, field);
>
> I would not put this comment here, better on the header when the field
> is declared? Same for the next one.
>
OK.
Thanks,
Jianjun
>> }
>> if (ret >= 0) {
>> ret = qemu_file_get_error(f);
>> @@ -328,7 +333,11 @@ void vmstate_save_state(QEMUFile *f, const
>> VMStateDescription *vmsd,
>> if (field->flags & VMS_STRUCT) {
>> vmstate_save_state(f, field->vmsd, addr, vmdesc_loop);
>> } else {
>> - field->info->put(f, addr, size);
>> + /* field and vmdesc_loop are always passed in. But they
>> + * should be ignored by put when not needed. They are
>> + * only needed in cases f customized handling, such as
>> + * migrating QTAILQ. */
>> + field->info->put(f, addr, size, field, vmdesc_loop);
>> }
>
>
> Rest of patch is ok.
>
