[Qemu-devel] Re: [PATCH v4] floppy: save and restore DIR register

[Paolo Bonzini <pbonzini@redhat.com>]

On 04/06/2011 02:13 PM, Juan Quintela wrote:
> Jason Wang<jasowang@redhat.com>  wrote:
>> We need to keep DIR register unchanged across migration, but currently it
>> depends on the media_changed flags from block layer. Since we do not
>> save/restore it and the bdrv_open() called in dest node may set the
>> media_changed flag when trying to open floppy image, guest driver may think the
>> floppy have changed after migration. To fix this, a new filed media_changed in
>> FDrive strcutre was introduced in order to save and restore the it from block
>> layer through pre_save/post_load callbacks.
>>
>> Signed-off-by: Jason Wang<jasowang@redhat.com>
>> ---
>>
>> Changed from V3:
>> According to Juan's suggestions, back to v2 and just add the checking for
>> media_changed "changed" in .needed.
>> Do not fail the migration when src have a drive but dest does not, we can treat
>> it as user ejected the floppy.
>>
>> Changed from V2:
>> According to Paolo's suggestions, a default_migration_media_changed property was
>> added to avoid saving subsections as much as possible. Its was set media_changed
>> in pre_load callback and then we can avoid the saving when it was equal to the
>> media_changed when migrating the FDrive. Behaviors of elder machine types are
>> also kept through compat_props.
>>
>> Changed from V1:
>> Check the drive->bs during post_load.
>>
>>   hw/fdc.c |   51 ++++++++++++++++++++++++++++++++++++++++++++++++++-
>>   1 files changed, 50 insertions(+), 1 deletions(-)
>>
>
> Reviewed-by: Juan Quintela<quintela@redhat.com>
>
> This solution is way less invasive that v3, and achieves exactly the
> same compatibility.

True, thanks for putting up with the reviews! :)

Acked-by: Paolo Bonzini <pbonzini@redhat.com>

Paolo