Re: [PULL 23/65] qapi: introduce device-sync-config

[Daniel P . Berrangé]

On Mon, Nov 04, 2024 at 04:07:00PM -0500, Michael S. Tsirkin wrote:
> From: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
> 
> Add command to sync config from vhost-user backend to the device. It
> may be helpful when VHOST_USER_SLAVE_CONFIG_CHANGE_MSG failed or not
> triggered interrupt to the guest or just not available (not supported
> by vhost-user server).
> 
> Command result is racy if allow it during migration. Let's not allow
> that.
> 
> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
> Reviewed-by: Markus Armbruster <armbru@redhat.com>
> Acked-by: Raphael Norwitz <raphael@enfabrica.net>
> Message-Id: <20240920094936.450987-4-vsementsov@yandex-team.ru>
> Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> ---
>  qapi/qdev.json            | 24 ++++++++++++++++++++++++
>  include/hw/qdev-core.h    |  6 ++++++
>  hw/block/vhost-user-blk.c |  1 +
>  hw/virtio/virtio-pci.c    |  9 +++++++++
>  system/qdev-monitor.c     | 38 ++++++++++++++++++++++++++++++++++++++
>  5 files changed, 78 insertions(+)
> 
> diff --git a/qapi/qdev.json b/qapi/qdev.json
> index 53d147c7b4..2a581129c9 100644
> --- a/qapi/qdev.json
> +++ b/qapi/qdev.json
> @@ -163,3 +163,27 @@
>  ##
>  { 'event': 'DEVICE_UNPLUG_GUEST_ERROR',
>    'data': { '*device': 'str', 'path': 'str' } }
> +
> +##
> +# @device-sync-config:
> +#
> +# Synchronize device configuration from host to guest part.  First,
> +# copy the configuration from the host part (backend) to the guest
> +# part (frontend).  Then notify guest software that device
> +# configuration changed.
> +#
> +# The command may be used to notify the guest about block device
> +# capcity change.  Currently only vhost-user-blk device supports
> +# this.
> +#
> +# @id: the device's ID or QOM path
> +#
> +# Features:
> +#
> +# @unstable: The command is experimental.
> +#
> +# Since: 9.1
> +##

Again, we're in the 9.2 dev cycle currently.


With regards,
Daniel
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