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helo=mail-wr1-x435.google.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, DKIM_SIGNED=0.1,\n DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1,\n HK_NAME_MR_MRS=0.998,\n RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001,\n SPF_PASS=-0.001 autolearn=no autolearn_force=no","X-Spam_action":"no action","X-Mailman-Approved-At":"Thu, 09 Apr 2026 04:19:20 -0400","X-BeenThere":"qemu-devel@nongnu.org","X-Mailman-Version":"2.1.29","Precedence":"list","List-Id":"qemu development ","List-Unsubscribe":",\n ","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n ","Errors-To":"qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org","Sender":"qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org"},"content":"This series adds two features that together enable transparent NVMe disk\nhot-swap simulation in QEMU, matching the behavior of physical NVMe\ndrives being pulled and reinserted in the same PCIe slot.\n\nProblem:\nCurrently, hot-swapping an NVMe disk in QEMU requires removing the\nentire NVMe controller via device_del, which causes the Linux guest to\nassign a new controller number on re-add (e.g. nvme2 becomes nvme4).\nThis breaks storage software that tracks drives by device name.\n\nSolution:\nPatch 1 adds hotplug support for nvme-ns devices on the NvmeBus, with\nproper Asynchronous Event Notification (AEN) so the guest kernel detects\nnamespace changes. This allows namespace-level hot-swap without removing\nthe NVMe controller.\n\nPatch 2 adds a drive_insert HMP command that reconnects a host block\ndevice file to an existing guest device after drive_del. This is the\ncounterpart to drive_del for non-removable devices where\nblockdev-change-medium cannot be used.\n\nThe recommended hot-swap sequence is:\n 1. drive_del # disconnect backing store\n 2. drive_insert # reconnect backing store\n 3. pcie_aer_inject_error SDN # trigger controller reset\n\nAfter this sequence, the guest sees the same controller and namespace\nnames (e.g. /dev/nvme2n1 remains /dev/nvme2n1), and the NVMe driver\nrecovers transparently via the standard AER recovery path.\n\nTested with:\n- Linux 6.1 guest on QEMU aarch64 with HVF (macOS)\n- NVMe subsystem model with multipath disabled\n- DirectPV and MinIO AIStor storage stack\n\nmr-083 (2):\n hw/nvme: add namespace hotplug support\n block/monitor: add drive_insert HMP command\n\n block/monitor/block-hmp-cmds.c | 59 +++++++++++++++++++++++\n hmp-commands.hx | 18 +++++++\n hw/nvme/ctrl.c | 85 ++++++++++++++++++++++++++++++++++\n hw/nvme/ns.c | 1 +\n hw/nvme/subsys.c | 2 +\n include/block/block-hmp-cmds.h | 1 +\n 6 files changed, 166 insertions(+)\n\n--\n2.50.1 (Apple Git-155)"}