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Tsirkin" , Stefano Garzarella , Kevin Wolf , Hanna Reitz , Fabiano Rosas , Eric Blake , Markus Armbruster , Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Subject: Re: [PATCH v3 0/3] vhost-user-blk: support inflight migration Message-ID: References: <20251110103937.1944486-1-dtalexundeer@yandex-team.ru> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Received-SPF: pass client-ip=170.10.133.124; envelope-from=peterx@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Wed, Dec 10, 2025 at 02:41:20PM +0300, Vladimir Sementsov-Ogievskiy wrote: > Yes, it can. And regardless of the way we chose: qdev properties or qapi, > I don't think we need a property for backend itself. We need a property > (or migration capability) for vhost-user-blk itself, saying that its > backend should be migrated. The problem is then we need to introduce the new property to all frontends that would support the backend? If it's a backend property, it can be one property for the backend that all the frontends can consume. > > It's a lot simpler to migrate backend inside of frontend state. If we > migrate backend in separate, we can't control the order of backend/frontend > stats, and will have to implement some late point in state load process, > where both are already loaded and we can do our post-load logic. Would MigrationPriority help when defining the VMSD? Thanks, -- Peter Xu