kernel/linux.git/drivers/vhost/vhost.h, branch v6.6.133

vhost_task: Handle SIGKILL by flushing work and exiting

2024-07-11T10:49:10+00:00

[ Upstream commit db5247d9bf5c6ade9fd70b4e4897441e0269b233 ] Instead of lingering until the device is closed, this has us handle SIGKILL by: 1. marking the worker as killed so we no longer try to use it with new virtqueues and new flush operations. 2. setting the virtqueue to worker mapping so no new works are queued. 3. running all the exiting works. Suggested-by: Edward Adam Davis Reported-and-tested-by: syzbot+98edc2df894917b3431f@syzkaller.appspotmail.com Message-Id: Signed-off-by: Mike Christie Message-Id: <20240316004707.45557-9-michael.christie@oracle.com> Signed-off-by: Michael S. Tsirkin Signed-off-by: Sasha Levin

vhost: Make parameter name match of vhost_get_vq_desc()

2023-07-03T16:15:15+00:00

The parameter name in the function declaration and definition should be the same. drivers/vhost/vhost.h, int vhost_get_vq_desc(..., unsigned int iov_count,...); drivers/vhost/vhost.c, int vhost_get_vq_desc(..., unsigned int iov_size,...) Signed-off-by: Xianting Tian Message-Id: <20230621093835.36878-1-xianting.tian@linux.alibaba.com> Signed-off-by: Michael S. Tsirkin

vhost: Allow worker switching while work is queueing

2023-07-03T16:15:14+00:00

This patch drops the requirement that we can only switch workers if work has not been queued by using RCU for the vq based queueing paths and a mutex for the device wide flush. We can also use this to support SIGKILL properly in the future where we should exit almost immediately after getting that signal. With this patch, when get_signal returns true, we can set the vq->worker to NULL and do a synchronize_rcu to prevent new work from being queued to the vhost_task that has been killed. Signed-off-by: Mike Christie Message-Id: <20230626232307.97930-18-michael.christie@oracle.com> Signed-off-by: Michael S. Tsirkin

vhost: allow userspace to create workers

2023-07-03T16:15:14+00:00

For vhost-scsi with 3 vqs or more and a workload that tries to use them in parallel like: fio --filename=/dev/sdb --direct=1 --rw=randrw --bs=4k \ --ioengine=libaio --iodepth=128 --numjobs=3 the single vhost worker thread will become a bottlneck and we are stuck at around 500K IOPs no matter how many jobs, virtqueues, and CPUs are used. To better utilize virtqueues and available CPUs, this patch allows userspace to create workers and bind them to vqs. You can have N workers per dev and also share N workers with M vqs on that dev. This patch adds the interface related code and the next patch will hook vhost-scsi into it. The patches do not try to hook net and vsock into the interface because: 1. multiple workers don't seem to help vsock. The problem is that with only 2 virtqueues we never fully use the existing worker when doing bidirectional tests. This seems to match vhost-scsi where we don't see the worker as a bottleneck until 3 virtqueues are used. 2. net already has a way to use multiple workers. Signed-off-by: Mike Christie Message-Id: <20230626232307.97930-16-michael.christie@oracle.com> Signed-off-by: Michael S. Tsirkin

vhost: replace single worker pointer with xarray

2023-07-03T16:15:14+00:00

The next patch allows userspace to create multiple workers per device, so this patch replaces the vhost_worker pointer with an xarray so we can store mupltiple workers and look them up. Signed-off-by: Mike Christie Message-Id: <20230626232307.97930-15-michael.christie@oracle.com> Signed-off-by: Michael S. Tsirkin

vhost: remove vhost_work_queue

2023-07-03T16:15:14+00:00

vhost_work_queue is no longer used. Each driver is using the poll or vq based queueing, so remove vhost_work_queue. Signed-off-by: Mike Christie Message-Id: <20230626232307.97930-13-michael.christie@oracle.com> Signed-off-by: Michael S. Tsirkin

vhost: convert poll work to be vq based

2023-07-03T16:15:13+00:00

This has the drivers pass in their poll to vq mapping and then converts the core poll code to use the vq based helpers. In the next patches we will allow vqs to be handled by different workers, so to allow drivers to execute operations like queue, stop, flush, etc on specific polls/vqs we need to know the mappings. Signed-off-by: Mike Christie Message-Id: <20230626232307.97930-8-michael.christie@oracle.com> Signed-off-by: Michael S. Tsirkin

vhost: take worker or vq for flushing

2023-07-03T16:15:13+00:00

This patch has the core work flush function take a worker. When we support multiple workers we can then flush each worker during device removal, stoppage, etc. It also adds a helper to flush specific virtqueues, so vhost-scsi can flush IO vqs from it's ctl vq. Signed-off-by: Mike Christie Message-Id: <20230626232307.97930-7-michael.christie@oracle.com> Signed-off-by: Michael S. Tsirkin

vhost: take worker or vq instead of dev for queueing

2023-07-03T16:15:13+00:00

This patch has the core work queueing function take a worker for when we support multiple workers. It also adds a helper that takes a vq during queueing so modules can control which vq/worker to queue work on. This temp leaves vhost_work_queue. It will be removed when the drivers are converted in the next patches. Signed-off-by: Mike Christie Message-Id: <20230626232307.97930-6-michael.christie@oracle.com> Signed-off-by: Michael S. Tsirkin

vhost, vhost_net: add helper to check if vq has work

2023-07-03T16:15:13+00:00

In the next patches each vq might have different workers so one could have work but others do not. For net, we only want to check specific vqs, so this adds a helper to check if a vq has work pending and converts vhost-net to use it. Signed-off-by: Mike Christie Acked-by: Jason Wang Message-Id: <20230626232307.97930-5-michael.christie@oracle.com> Signed-off-by: Michael S. Tsirkin