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envelope-from=jgg@nvidia.com; helo=DM5PR21CU001.outbound.protection.outlook.com X-Spam_score_int: -10 X-Spam_score: -1.1 X-Spam_bar: - X-Spam_report: (-1.1 / 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, FORGED_SPF_HELO=1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001, SPF_HELO_PASS=-0.001, SPF_NONE=0.001 autolearn=no 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 Tue, Dec 30, 2025 at 11:42:09AM -0500, Pasha Tatashin wrote: > > One question: in the intended LUOD/session architecture, do you still expect > > clients (or a wrapper) to inject the retrieved guest RAM memfd FD into QEMU > > via -add-fd + /dev/fdset/ at QEMU startup? (as this patchset does) > > > > Or is the longer-term plan that QEMU itself connects to LUOD over UDS, retrieves > > the session/resource FD directly, and consumes it as the RAM backing without > > going through -add-fd? > > The latter, I expect QEMU and other VMMs use their LUO session FDs > that they receive from LUOD to retrieve and restore the preserved > resources: memfd+iommufd+vfiofd and resume the suspended VMs. Right, and we shouldn't have something like /dev/fset/ID at all. The VMM has to know it is doing a LUO restoration and squence restoration of all the stuff the preserving VMM put into LUO. The general case is far more complex than just opening a memfd. Jason