From: Xie Yongji <xieyon...@baidu.com> This patchset is aimed at supporting qemu to reconnect vhost-user-blk backend after vhost-user-blk backend crash or restart.
The patch 1 introduces two new messages VHOST_USER_GET_INFLIGHT_FD and VHOST_USER_SET_INFLIGHT_FD to support support transferring shared buffer between qemu and backend. The patch 2,3 are the corresponding libvhost-user patches of patch 1. Make libvhost-user support VHOST_USER_GET_INFLIGHT_FD and VHOST_USER_SET_INFLIGHT_FD. The patch 4 allows vhost-user-blk to use the two new messages to get/set inflight buffer from/to backend. The patch 5 supports vhost-user-blk to reconnect backend when connection closed. The patch 6 introduces VHOST_USER_PROTOCOL_F_SLAVE_SHMFD to vhost-user-blk backend which is used to tell qemu that we support reconnecting now. This series is based on Daniel P. Berrangé's patchset: https://lists.gnu.org/archive/html/qemu-devel/2019-01/msg03344.html To use it, we could start qemu with: qemu-system-x86_64 \ -chardev socket,id=char0,path=/path/vhost.socket,reconnect=1, \ -device vhost-user-blk-pci,chardev=char0 \ and start vhost-user-blk backend with: vhost-user-blk -b /path/file -s /path/vhost.socket Then we can restart vhost-user-blk at any time during VM running. V4 to V5: - Drop patch that enables "nowait" option on client sockets - Support resubmitting inflight I/O in order - Make inflight I/O tracking more robust - Remove align field and add queue size field in VhostUserInflight - Document more details in vhost-user.txt V3 to V4: - Drop messages VHOST_USER_GET_SHM_SIZE and VHOST_USER_SET_SHM_FD - Introduce two new messages VHOST_USER_GET_INFLIGHT_FD and VHOST_USER_SET_INFLIGHT_FD - Allocate inflight buffer in backend rather than in qemu - Document a recommended format for inflight buffer V2 to V3: - Using exisiting wait/nowait options to control connection on client sockets instead of introducing "disconnected" option. - Support the case that vhost-user backend restart during initialzation of vhost-user-blk device. V1 to V2: - Introduce "disconnected" option for chardev instead of reuse "wait" option - Support the case that QEMU starts before vhost-user backend - Drop message VHOST_USER_SET_VRING_INFLIGHT - Introduce two new messages VHOST_USER_GET_SHM_SIZE and VHOST_USER_SET_SHM_FD Xie Yongji (6): vhost-user: Support transferring inflight buffer between qemu and backend libvhost-user: Introduce vu_queue_map_desc() libvhost-user: Support tracking inflight I/O in shared memory vhost-user-blk: Add support to get/set inflight buffer vhost-user-blk: Add support to reconnect backend contrib/vhost-user-blk: enable inflight I/O tracking Makefile | 2 +- contrib/libvhost-user/libvhost-user.c | 402 ++++++++++++++++++++---- contrib/libvhost-user/libvhost-user.h | 40 +++ contrib/vhost-user-blk/vhost-user-blk.c | 3 +- docs/interop/vhost-user.txt | 101 ++++++ hw/block/vhost-user-blk.c | 227 ++++++++++--- hw/virtio/vhost-user.c | 110 +++++++ hw/virtio/vhost.c | 105 +++++++ include/hw/virtio/vhost-backend.h | 10 + include/hw/virtio/vhost-user-blk.h | 5 + include/hw/virtio/vhost.h | 19 ++ 11 files changed, 925 insertions(+), 99 deletions(-) -- 2.17.1
