Re: [Qemu-devel] [PATCH 2/4] migration/savevm: use migration_is_blocked to validate

[Wei Yang]

On Wed, May 15, 2019 at 02:38:27PM +0800, Wei Yang wrote:
>On Tue, May 14, 2019 at 04:18:14PM +0100, Dr. David Alan Gilbert wrote:
>>* Wei Yang (address@hidden) wrote:
>>> 
>>> Well, when you look into the source side of migration:
>>> 
>>> qmp_migrate
>>>   migrate_prepare
>>>     migration_is_blocked
>>> 
>>> This means if migration_is_blocked fails, the source will not start 
>>> migration.
>>> And it is the same as save_snapshot.
>>> 
>>> From my understanding, when we load a vm, it should check the same
>>> requirement.
>>
>>I've been thinking about this, and I think I agree with Daniel on this.
>>The 'migration_blockers' list tells you that something about the
>>*current* state of a device means that it can't be migrated - e.g.
>>a 9pfs with a mounted filesystem can't be migrated.
>>
>>If we're about to reload the state from a snapshot, then the saved
>>snapshot's state must have been migratable, so that's OK.
>>
>
>The situation is on a vm with 'migration_blockers' still could reload from a
>snapshot.
>
>This sounds reasonable. Thanks :-)
>

Well, this is still a little strange. The means source vm and destination vm
could have different configuration. Is this common?

-- 
Wei Yang
Help you, Help me