Re: [Qemu-devel] [PATCH RFC v3 00/14] Dirty bitmaps migration

[John Snow]

On 02/18/2015 09:00 AM, Vladimir Sementsov-Ogievskiy wrote:
>   rfc: there are two tests. They are the same but using different
>   interfaces: md5 checksum of the bitmap last layer in query-block or
>   separate query-block-dirty-bitmap with dirty bitmap regions.
>   The second form is more appropriate for debugging, the first is more
>   appropriate for simple regression control. Which should go to
>   upstream?

Long term: The checksum for regression control. I think the region 
output by query-block-dirty-bitmap may be somewhat excessive during 
production use (a large bitmap may have many, many dirty bits) so its 
usage may be limited there.

It's definitely very useful as a debug command; but the checksum is 
likely more useful for the regression tests as you say.

We'll likely need to debug the bitmaps and the migration thereof for 
quite a bit of time in the near future, though, so it'd be a shame to 
discard the nice debugging interface. I wonder if we can conditionally 
compile in QMP commands exposed only in debug builds?

I don't think we have any like that yet, but I could see a use for them.

Thanks,
--js