| Message ID | 20190122083152.10705-1-xieyongji@baidu.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | vhost-user-blk: Add support for backend reconnecting | expand |
On 2019/1/22 下午4:31, elohimes@gmail.com wrote: > From: Xie Yongji <xieyongji@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 I'm still not convinced about this approach. If the maintainer decide to merge, at least two things needs to be added besides the correctness of the code: - you need prove that this approach can work for packed ring - an unit-test to test the crash during logging in-flight descriptor. Thanks > > 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(-) >
On Wed, Jan 30, 2019 at 10:29:10AM +0800, Jason Wang wrote: > > On 2019/1/22 下午4:31, elohimes@gmail.com wrote: > > From: Xie Yongji <xieyongji@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 > > > I'm still not convinced about this approach. If the maintainer decide to > merge, at least two things needs to be added besides the correctness of the > code: > > - you need prove that this approach can work for packed ring Or rather document how it's used. > - an unit-test to test the crash during logging in-flight descriptor. > > Thanks For contrib/vhost-user-blk? Well I don't think it's used by unit tests right now, it is? So it's a worthwhile goal but not necessarily a requirement for any specific patch I think. > > > > > 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(-) > >
From: Xie Yongji <xieyongji@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(-)