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([2001:b07:6468:f312:c8dd:75d4:99ab:290a]) by smtp.gmail.com with ESMTPSA id t6sm1620693wrp.68.2020.10.29.06.06.07 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 29 Oct 2020 06:06:08 -0700 (PDT) Subject: Re: Out-of-Process Device Emulation session at KVM Forum 2020 To: Jason Wang , Stefan Hajnoczi , Stefan Hajnoczi References: <20201027151400.GA138065@stefanha-x1.localdomain> From: Paolo Bonzini Message-ID: <7977d79c-0e2b-9a71-631e-77811b508bd7@redhat.com> Date: Thu, 29 Oct 2020 14:06:06 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.3.1 MIME-Version: 1.0 In-Reply-To: Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=pbonzini@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=216.205.24.124; envelope-from=pbonzini@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/10/29 00:47:54 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -23 X-Spam_score: -2.4 X-Spam_bar: -- X-Spam_report: (-2.4 / 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, NICE_REPLY_A=-0.261, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, 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?Q?Marc-Andr=c3=a9_Lureau?= , Jens Freimann , =?UTF-8?Q?Philippe_Mathieu-Daud=c3=a9?= , Stefano Garzarella , Eduardo Habkost , Sergio Lopez , Kashyap Chamarthy , Darren Kenny , Liran Alon , =?UTF-8?Q?Alex_Benn=c3=a9e?= , David Gibson , Kevin Wolf , Halil Pasic , "Daniel P. Berrange" , Christophe de Dinechin , Thanos Makatos , fam Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 29/10/20 14:02, Jason Wang wrote: > > > 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. The nested live migration data is an opaque blob. The format is documented by the kernel; for Intel it is also guest-visible. However QEMU doesn't try to parse it. Paolo