Hi, it's very interesting patchset. I also research reconnecting issue for vhost-user-blk and SPDK. Did you support a case when vhost backend is not started but QEMU does?
Regards, Yury 06.12.2018, 09:37, "elohi...@gmail.com" <elohi...@gmail.com>: > 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 tries to implenment the sync connection for > "reconnect socket". > > The patch 2 introduces a new message VHOST_USER_SET_VRING_INFLIGHT > to support offering shared memory to backend to record > its inflight I/O. > > The patch 3,4 are the corresponding libvhost-user patches of > patch 2. Make libvhost-user support VHOST_USER_SET_VRING_INFLIGHT. > > The patch 5 supports vhost-user-blk to reconnect backend when > connection closed. > > The patch 6 tells qemu that we support reconnecting now. > > To use it, we could start qemu with: > > qemu-system-x86_64 \ > -chardev socket,id=char0,path=/path/vhost.socket,reconnect=1,wait \ > -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. > > Xie Yongji (6): > char-socket: Enable "wait" option for client mode > vhost-user: Add shared memory to record inflight I/O > libvhost-user: Introduce vu_queue_map_desc() > libvhost-user: Support recording inflight I/O in shared memory > vhost-user-blk: Add support for reconnecting backend > contrib/vhost-user-blk: enable inflight I/O recording > > chardev/char-socket.c | 5 +- > contrib/libvhost-user/libvhost-user.c | 215 ++++++++++++++++++++---- > contrib/libvhost-user/libvhost-user.h | 19 +++ > contrib/vhost-user-blk/vhost-user-blk.c | 3 +- > hw/block/vhost-user-blk.c | 169 +++++++++++++++++-- > hw/virtio/vhost-user.c | 69 ++++++++ > hw/virtio/vhost.c | 8 + > include/hw/virtio/vhost-backend.h | 4 + > include/hw/virtio/vhost-user-blk.h | 4 + > include/hw/virtio/vhost-user.h | 8 + > 10 files changed, 452 insertions(+), 52 deletions(-) > > -- > 2.17.1
