[RFC PATCH 0/7] Fix issue when storage migration is requested but there are no disks to migrate

[Andrea Bolognani]

On Tue, 2021-04-13 at 17:38 +0200, Peter Krempa wrote:
> In certain weird cases and due to very crusty code we'd instruct qemu to
> migrate storage using the old style storage migration when there wasn't
> anything to migrate. This was caused by a recent refactor.
> 
> Note that the series is RFC as I didn't really test it yet, but feel
> free to provide feedback.
> 
> Peter Krempa (7):
>   util: xml: Introduce virXMLFormatElementEmpty
>   qemuMigrationCookieNBDXMLFormat: Format empty <nbd/> element
>   qemuMigrationSrcNBDStorageCopy: Return error code on error
>   qemuMigrationSrcNBDStorageCopy: Don't pass migrate_flags
>   qemuMigrationSrcRun: Sanitize setting of cookieFlags and migrate_flags
>     on storage migration
>   qemuMigrationSrcRun: Don't attempt any storage migration if no disks
>     will be migrated
>   qemuMigrationSrcBeginPhase: Don't offer 'nbd' in cookie if there are
>     no disks to migrate

My knowledge of migration code is such that, while your changes look
reasonable overall, I don't feel too confident ACKing them myself and
would prefer if someone with more expertise in the area would go over
them instead.

I can, however, offer a

  Tested-by: Andrea Bolognani <abologna at redhat.com>

for the series, as I have verified that it makes the KubeVirt test
suite failure that brought this issue to our attention in the first
place go away.

-- 
Andrea Bolognani / Red Hat / Virtualization