Re: [Qemu-devel] [PATCH v6 03/14] migration: Add post_save function to VMStateDescription

[Juan Quintela]

Richard Henderson <address@hidden> wrote:
> On 10/10/18 1:37 PM, Aaron Lindsay wrote:
>> In some cases it may be helpful to modify state before saving it for
>> migration, and then modify the state back after it has been saved. The
>> existing pre_save function provides half of this functionality. This
>> patch adds a post_save function to provide the second half.
>> 
>> Signed-off-by: Aaron Lindsay <address@hidden>
>> ---
>>  docs/devel/migration.rst    |  9 +++++++--
>>  include/migration/vmstate.h |  1 +
>>  migration/vmstate.c         | 10 +++++++++-
>>  3 files changed, 17 insertions(+), 3 deletions(-)
>
> Hmm, maybe.  I believe the common practice is for pre_save to copy state into 
> a
> separate member on the side, so that conversion back isn't necessary.

Hi

Originally we have that function.  We removed it because we had not
remaining uses for it on tree.  I am not againt getting it if you need
it.

Once told that, I think you can add a return value as David saide.

And once there, it ia good thing that you document it if it is called
"before" or "after" the subsections_save.  There are arguments for doing
it either way, just document it.

Thanks, Juan.