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That's all we know. 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, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=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: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Elena Ufimtseva , John G Johnson , "mst@redhat.com" , Janosch Frank , qemu-devel , Kirti Wankhede , Gerd Hoffmann , Yan Vugenfirer , Jag Raman , Anup Patel , Claudio Imbrenda , Christian Borntraeger , Roman Kagan , Felipe Franciosi , =?UTF-8?B?TWFyYy1BbmRyw6kgTHVyZWF1?= , Jens Freimann , =?UTF-8?Q?Philippe_Mathieu=2DDaud=C3=A9?= , Stefano Garzarella , Eduardo Habkost , Sergio Lopez , Kashyap Chamarthy , Darren Kenny , Liran Alon , Stefan Hajnoczi , Thanos Makatos , =?UTF-8?B?QWxleCBCZW5uw6ll?= , David Gibson , Kevin Wolf , Halil Pasic , "Daniel P. Berrange" , Christophe de Dinechin , Paolo Bonzini , fam Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Thu, Oct 29, 2020 at 1:03 PM Jason Wang wrote: > On 2020/10/29 =E4=B8=8B=E5=8D=888:08, Stefan Hajnoczi wrote: > > Here are notes from the session: > > > > protocol stability: > > * vhost-user already exists for existing third-party applications > > * vfio-user is more general but will take more time to develop > > * libvfio-user can be provided to allow device implementations > > > > management: > > * Should QEMU launch device emulation processes? > > * Nicer user experience > > * Technical blockers: forking, hotplug, security is hard once > > QEMU has started running > > * Probably requires a new process model with a long-running > > QEMU management process proxying QMP requests to the emulator process > > > > migration: > > * dbus-vmstate > > * VFIO live migration ioctls > > * Source device can continue if migration fails > > * Opaque blobs are transferred to destination, destination can > > fail migration if it decides the blobs are incompatible > > > I'm not sure this can work: > > 1) Reading something that is opaque to userspace is probably a hint of > bad uAPI design > 2) Did qemu even try to migrate opaque blobs before? It's probably a bad > design of migration protocol as well. > > It looks to me have a migration driver in qemu that can clearly define > each byte in the migration stream is a better approach. Here is the kernel patch series if you want to review it: https://lore.kernel.org/kvm/20191203110412.055c38df@x1.home/t/ There is also a QEMU patch series: https://patchwork.kernel.org/project/qemu-devel/cover/1566845753-18993-1-gi= t-send-email-kwankhede@nvidia.com/ Kirti is also on the CC list if you want to discuss specific questions. Stefan