Re: [RFC] migration: Add migrate-set-bitmap-node-mapping

[Eric Blake]

On 5/13/20 9:49 AM, Max Reitz wrote:
> This command allows mapping block node names to aliases for the purpose
> of block dirty bitmap migration.
>
> This way, management tools can use different node names on the source
> and destination and pass the mapping of how bitmaps are to be
> transferred to qemu (on the source, the destination, or even both with
> arbitrary aliases in the migration stream).
>
> Suggested-by: Vladimir Sementsov-Ogievskiy <address@hidden>
> Signed-off-by: Max Reitz <address@hidden>
> ---
> Branch: https://github.com/XanClic/qemu.git migration-bitmap-mapping-rfc
> Branch: https://git.xanclic.moe/XanClic/qemu.git migration-bitmap-mapping-rfc
>
> Vladimir has proposed something like this in April:
> https://lists.nongnu.org/archive/html/qemu-block/2020-04/msg00171.html
>
> Now I’ve been asked by my manager to look at this, so I decided to just
> write a patch to see how it’d play out.
>
> This is an RFC, because I’d like to tack on tests to the final version,
> but I’m not sure whether I can come up with something before the end of
> the week (and I’ll be on PTO for the next two weeks).
>
> Also, I don’t know whether migration/block-dirty-bitmap.c is the best
> place to put qmp_migrate_set_bitmap_mapping(), but it appears we already
> have some QMP handlers in migration/, so I suppose it isn’t too bad.

My 'qemu-img bitmap' series has block/monitor/bitmap-qmp-cmds.c - 
perhaps that's a decent location?  Or maybe another new file in that 
directory, if putting it directly in an existing file would drag in too 
much into qemu-img?

> ---
>   qapi/migration.json            | 36 ++++++++++++++++++++
>   migration/block-dirty-bitmap.c | 60 ++++++++++++++++++++++++++++++++--
>   2 files changed, 94 insertions(+), 2 deletions(-)

But I see you've already posted a v2, so I'll stop reviewing here and 
switch to that thread.

--
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3226
Virtualization:  qemu.org | libvirt.org