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([2001:b07:6468:f312:310b:68e5:c01a:3778]) by smtp.gmail.com with ESMTPSA id 68sm9965907wmz.40.2020.07.30.10.15.52 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 30 Jul 2020 10:15:53 -0700 (PDT) Subject: Re: [PATCH V1 00/32] Live Update To: Steve Sistare , qemu-devel@nongnu.org References: <1596122076-341293-1-git-send-email-steven.sistare@oracle.com> From: Paolo Bonzini Message-ID: <37635d27-b63f-f200-fa89-ccb6f7eba7f6@redhat.com> Date: Thu, 30 Jul 2020 19:15:52 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.9.0 MIME-Version: 1.0 In-Reply-To: <1596122076-341293-1-git-send-email-steven.sistare@oracle.com> Content-Language: en-US X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=207.211.31.81; envelope-from=pbonzini@redhat.com; helo=us-smtp-delivery-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/07/30 03:51:24 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -40 X-Spam_score: -4.1 X-Spam_bar: ---- X-Spam_report: (-4.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1, 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_H2=-1, 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: "Daniel P. Berrange" , "Michael S. Tsirkin" , =?UTF-8?Q?Philippe_Mathieu-Daud=c3=a9?= , Juan Quintela , "Dr. David Alan Gilbert" , Markus Armbruster , Alex Williamson , Stefan Hajnoczi , =?UTF-8?Q?Marc-Andr=c3=a9_Lureau?= , =?UTF-8?Q?Alex_Benn=c3=a9e?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 30/07/20 17:14, Steve Sistare wrote: > The first set of patches adds the cprsave and cprload commands to save and > restore VM state, and allow the host kernel to be updated and rebooted in > between. The VM must create guest RAM in a persistent shared memory file, > such as /dev/dax0.0 or persistant /dev/shm PKRAM as proposed in > https://lore.kernel.org/lkml/1588812129-8596-1-git-send-email-anthony.yznaga@oracle.com/ > > cprsave stops the VCPUs and saves VM device state in a simple file, and > thus supports any type of guest image and block device. The caller must > not modify the VM's block devices between cprsave and cprload. Stupid question, what does cpr stand for? If it is checkpoint/restore, please spell it out. Also, how does the functionality compare to xen-save-devices-state and xen-load-devices-state? > cprsave and cprload support guests with vfio devices if the caller first > suspends the guest by issuing guest-suspend-ram to the qemu guest agent. > The guest drivers suspend methods flush outstanding requests and re- > initialize the devices, and thus there is no device state to save and > restore. This probably should be allowed even for regular migration. Can you generalize the code as a separate series? Thanks, Paolo