Stateful vhost devices may need to free resources or clear device state upon device reset. The vhost-user protocol has a VHOST_USER_RESET_DEVICE message for this and vDPA has SET_STATUS 0, but only QEMU's vhost-user-scsi device actually implements this today.
This patch series performs device reset across all device types. When virtio_reset() is called, the associated vhost_dev's ->vhost_reset_device() is called. vhost-user-scsi's one-off implementation is obsoleted and removed. This patch affects behavior as follows: - vhost-kernel: no change in behavior. No ioctl calls are made. - vhost-user: back-ends that negotiate VHOST_USER_PROTOCOL_F_RESET_DEVICE now receive a VHOST_USER_DEVICE_RESET message upon device reset. Otherwise there is no change in behavior. DPDK, SPDK, libvhost-user, and the vhost-user-backend crate do not negotiate VHOST_USER_PROTOCOL_F_RESET_DEVICE automatically. - vhost-vdpa: an extra SET_STATUS 0 call is made during device reset. I have tested this series with vhost-net (kernel), vhost-user-blk, and vhost-user-fs (both Rust and legacy C). Stefan Hajnoczi (3): vhost-user: do not send RESET_OWNER on device reset vhost-backend: remove vhost_kernel_reset_device() virtio: call ->vhost_reset_device() during reset include/hw/virtio/vhost.h | 3 +++ hw/scsi/vhost-user-scsi.c | 20 -------------------- hw/virtio/vhost-backend.c | 6 ------ hw/virtio/vhost-user.c | 13 +++++++++---- hw/virtio/vhost.c | 9 +++++++++ hw/virtio/virtio.c | 4 ++++ 6 files changed, 25 insertions(+), 30 deletions(-) -- 2.41.0
