[PATCH 1/3] qemu: capabilities: Disable detection of QEMU_CAPS_BLOCK_EXPORT_ADD

[Eric Blake]

On 10/29/20 12:10 PM, Peter Krempa wrote:
> On Mon, Oct 26, 2020 at 08:36:50 -0500, Eric Blake wrote:
>> On 10/26/20 8:19 AM, Peter Krempa wrote:
>>> We use the capability to switch to using 'block-export-add' in the
>>> upcoming qemu release instead of the at the same time deprecated
>>> 'nbd-server-add'.
>>>
>>> Unfortunately qemu wants to change the interface of 'block-export-add'
>>> before the release. Since we've tried to stay up to date and added the
>>> code before it was written in stone, we need to disable the use of the
>>> new interface for the upcoming libvirt release so that we don't have a
>>> version of libvirt which would not work with the upcoming qemu version.
>>>
>>> Remove the detection of 'block-export-add' until we are more sure how
>>> the qemu interface will look.
>>>
>>> This patch partially reverts commit adb9f7123adb94645
>>>
>>> Signed-off-by: Peter Krempa <pkrempa at redhat.com>
>>> ---
>>>  src/qemu/qemu_capabilities.c                     | 1 -
>>>  tests/qemucapabilitiesdata/caps_5.2.0.x86_64.xml | 1 -
>>>  2 files changed, 2 deletions(-)
>>
>> Reviewed-by: Eric Blake <eblake at redhat.com>
>>
>> Safe for libvirt now no matter what happens in qemu's soft freeze this week.
> 
> I've pushed this patch, since Jirka is about to cut 'rc2' of libvirt and
> the qemu changes didn't hit upstream yet.

I see libvirt 6.9 is out now, so we can now proceed with the rest of the
series.  The qemu patches are now officially upstream (the whole series
is in, but the qapi changes are in this one):

commit cbad81cef8cc7b220f04600997ea29d7302bae00
Author: Eric Blake <eblake at redhat.com>
Date:   Tue Oct 27 00:05:49 2020 -0500

    nbd: Update qapi to support exporting multiple bitmaps

    Since 'block-export-add' is new to 5.2, we can still tweak the
    interface; there, allowing 'bitmaps':['str'] is nicer than
    'bitmap':'str'.  This wires up the qapi and qemu-nbd changes to permit
    passing multiple bitmaps as distinct metadata contexts that the NBD
    client may request, but the actual support for more than one will
    require a further patch to the server.

    Note that there are no changes made to the existing deprecated
    'nbd-server-add' command; this required splitting the QAPI type
    BlockExportOptionsNbd, which fortunately does not affect QMP
    introspection.

    Signed-off-by: Eric Blake <eblake at redhat.com>
    Message-Id: <20201027050556.269064-5-eblake at redhat.com>
    Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov at virtuozzo.com>
    Reviewed-by: Peter Krempa <pkrempa at redhat.com>


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