Re: [PATCH] drop libxml2 checks since libxml is not actually used (for parallels)

["Denis V. Lunev" <den@openvz.org>]

On 1/19/22 12:35 PM, Daniel P. Berrangé wrote:
> Copying the maintainers for block/parallels.c
>
> On Wed, Jan 19, 2022 at 12:04:23PM +0300, Michael Tokarev wrote:
>> [This is a trivial patch, but due to the number of files it touches
>> I'm not using qemu-trivial@ route.]
>>
>> For a long time, we assumed that libxml2 is neecessary for parallels
>> block format support (block/parallels*). However, this format actually
>> does not use libxml. Since this is the only user of libxml2 in while
>> qemu tree, we can drop all libxml2 checks and dependencies too.
>>
>> It is even more: --enable-parallels configure option was the only
>> option which was silently ignored when it's (fake) dependency
>> (libxml2) isn't installed.
> This option was added in this PULL request;
>
>   commit 25bfd5a75fa3e8f5796656c7634e26193f7bedc1 (HEAD)
>   Merge: 238e2d93c9 bcbb3866da
>   Author: Peter Maydell <peter.maydell@linaro.org>
>   Date:   Wed Jan 24 15:28:36 2018 +0000
>
>     Merge remote-tracking branch 'remotes/stefanha/tags/block-pull-request' into staging
>     
>     Pull request
>     
>     v2:
>      * Drop merge failure from a previous pull request that broke virtio-blk on ARM
>        guests
>      * Add Parallels XML patch series
>        
>     * remotes/stefanha/tags/block-pull-request:
>       block/parallels: add backing support to readv/writev
>       block/parallels: replace some magic numbers
>       block/parallels: move some structures into header
>       configure: add dependency
>       docs/interop/prl-xml: description of Parallels Disk format
>       block: add block_set_io_throttle virtio-blk-pci QMP example
>     
>     Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
>
> If i look back at the mailing list archives I find
>
>  v1: https://lists.nongnu.org/archive/html/qemu-devel/2017-12/msg03440.html
>  v2: https://lists.nongnu.org/archive/html/qemu-devel/2018-01/msg01870.html
>  v3: https://lists.nongnu.org/archive/html/qemu-devel/2018-01/msg02443.html
>
> which says
>
> [quote]
>    This series contains very basic
>    description of this XML files and makes preparations for actual
>    implementation to be followed.
> [/quote]
>
> but obviously the actual implementation never merged. I'm not sure
> if it was even posted, I didn't see anything in the mail archives
> forthe next couple of months, but didn't look beyond that.
>
> Denis: can you explain the status of XML support for the parallels
> block driver. Is this something you are carrying out of tree, or
> has the need for it gone away entirely ? Is there any reason why
> QEMU should keep this logic for probing for libxml2 for parallels ?
>
>>  .cirrus.yml                                     | 1 -
>>  .gitlab-ci.d/cirrus/freebsd-12.vars             | 2 +-
>>  .gitlab-ci.d/cirrus/freebsd-13.vars             | 2 +-
>>  .gitlab-ci.d/cirrus/macos-11.vars               | 2 +-
>>  .gitlab-ci.d/windows.yml                        | 2 --
>>  block/meson.build                               | 3 +--
>>  meson.build                                     | 6 ------
>>  meson_options.txt                               | 2 --
>>  scripts/ci/org.centos/stream/8/x86_64/configure | 1 -
>>  scripts/coverity-scan/coverity-scan.docker      | 1 -
>>  scripts/coverity-scan/run-coverity-scan         | 2 +-
>>  tests/docker/dockerfiles/alpine.docker          | 1 -
>>  tests/docker/dockerfiles/centos8.docker         | 1 -
>>  tests/docker/dockerfiles/fedora.docker          | 1 -
>>  tests/docker/dockerfiles/opensuse-leap.docker   | 1 -
>>  tests/docker/dockerfiles/ubuntu1804.docker      | 1 -
>>  tests/docker/dockerfiles/ubuntu2004.docker      | 1 -
>>  17 files changed, 5 insertions(+), 25 deletions(-)
> Note, this will conflict with pending PULL request that
> changes most of those dockerfiles and cirrus CI configs
> to be auto-generated
>
>   https://lists.nongnu.org/archive/html/qemu-devel/2022-01/msg02585.html
>
>
> Regards,
> Daniel
I think we can drop this. If that will be needed again - we will simply add.

Den