This series allows a QEMU guest to be migrated while it is connected to Passt using vhost-user interface. There are two parts: - first part enables the migration of QEMU without transferring the internal state of Passt. All connections are lost. This is done by implementing VHOST_USER_SET_LOG_FD and VHOST_USER_SET_LOG_BASE commands (and enabling VHOST_USER_PROTOCOL_F_LOG_SHMFD feature) "vhost-user: add VHOST_USER_SET_LOG_FD command" "vhost-user: add VHOST_USER_SET_LOG_BASE command" "vhost-user: Report to front-end we support VHOST_USER_PROTOCOL_F_LOG_SHMFD" - second part allows source Passt instance to send its internal state using QEMU migration channel to destination Passt instance. This is done implementing VHOST_USER_SET_DEVICE_STATE_FD and VHOST_USER_CHECK_DEVICE_STATE (and enabling VHOST_USER_PROTOCOL_F_DEVICE_STATE feature). "vhost-user: add VHOST_USER_CHECK_DEVICE_STATE command" "vhost-user: add VHOST_USER_SET_DEVICE_STATE_FD command" "vhost-user: Report to front-end we support VHOST_USER_PROTOCOL_F_DEVICE_STATE" For now, it only implements the function needed to transfer the state but no state is transferred. VHOST_USER_PROTOCOL_F_DEVICE_STATE is implemented in QEMU only for vhost-user-fs, to be able to use it with virtio-net I have proposed a patch upstream: https://patchew.org/QEMU/20241218143453.1573185-1-lvivier@redhat.com/ Laurent Vivier (9): virtio: Use const pointer for vu_dev vhost-user: update protocol features and commands list vhost-user: add VHOST_USER_SET_LOG_FD command vhost-user: Pass vu_dev to more virtio functions vhost-user: add VHOST_USER_SET_LOG_BASE command vhost-user: Report to front-end we support VHOST_USER_PROTOCOL_F_LOG_SHMFD vhost-user: add VHOST_USER_CHECK_DEVICE_STATE command vhost-user: add VHOST_USER_SET_DEVICE_STATE_FD command vhost-user: Report to front-end we support VHOST_USER_PROTOCOL_F_DEVICE_STATE epoll_type.h | 2 + passt.c | 4 + util.h | 3 + vhost_user.c | 251 ++++++++++++++++++++++++++++++++++++++++++++++++++- vhost_user.h | 50 +++++++++- virtio.c | 116 +++++++++++++++++++++--- virtio.h | 32 +++++-- vu_common.c | 59 +++++++++++- vu_common.h | 3 +- 9 files changed, 484 insertions(+), 36 deletions(-) -- 2.47.1