From: Mike Christie Date: Fri, 10 Mar 2023 22:03:31 +0000 (-0600) Subject: vhost: move worker thread fields to new struct X-Git-Tag: v6.6.7~3062^2~1 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=1a5f8090c6de99306f4212dc7adfc6189a616eb9;p=platform%2Fkernel%2Flinux-starfive.git vhost: move worker thread fields to new struct This is just a prep patch. It moves the worker related fields to a new vhost_worker struct and moves the code around to create some helpers that will be used in the next patch. Signed-off-by: Mike Christie Acked-by: Michael S. Tsirkin Reviewed-by: Stefan Hajnoczi Reviewed-by: Christoph Hellwig Signed-off-by: Christian Brauner (Microsoft) Signed-off-by: Christian Brauner --- diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index f11bdbe..dc7f823 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -255,8 +255,8 @@ void vhost_work_queue(struct vhost_dev *dev, struct vhost_work *work) * sure it was not in the list. * test_and_set_bit() implies a memory barrier. */ - llist_add(&work->node, &dev->work_list); - wake_up_process(dev->worker); + llist_add(&work->node, &dev->worker->work_list); + wake_up_process(dev->worker->task); } } EXPORT_SYMBOL_GPL(vhost_work_queue); @@ -264,7 +264,7 @@ EXPORT_SYMBOL_GPL(vhost_work_queue); /* A lockless hint for busy polling code to exit the loop */ bool vhost_has_work(struct vhost_dev *dev) { - return !llist_empty(&dev->work_list); + return dev->worker && !llist_empty(&dev->worker->work_list); } EXPORT_SYMBOL_GPL(vhost_has_work); @@ -335,7 +335,8 @@ static void vhost_vq_reset(struct vhost_dev *dev, static int vhost_worker(void *data) { - struct vhost_dev *dev = data; + struct vhost_worker *worker = data; + struct vhost_dev *dev = worker->dev; struct vhost_work *work, *work_next; struct llist_node *node; @@ -350,7 +351,7 @@ static int vhost_worker(void *data) break; } - node = llist_del_all(&dev->work_list); + node = llist_del_all(&worker->work_list); if (!node) schedule(); @@ -360,7 +361,7 @@ static int vhost_worker(void *data) llist_for_each_entry_safe(work, work_next, node, node) { clear_bit(VHOST_WORK_QUEUED, &work->flags); __set_current_state(TASK_RUNNING); - kcov_remote_start_common(dev->kcov_handle); + kcov_remote_start_common(worker->kcov_handle); work->fn(work); kcov_remote_stop(); if (need_resched()) @@ -479,7 +480,6 @@ void vhost_dev_init(struct vhost_dev *dev, dev->byte_weight = byte_weight; dev->use_worker = use_worker; dev->msg_handler = msg_handler; - init_llist_head(&dev->work_list); init_waitqueue_head(&dev->wait); INIT_LIST_HEAD(&dev->read_list); INIT_LIST_HEAD(&dev->pending_list); @@ -571,10 +571,60 @@ static void vhost_detach_mm(struct vhost_dev *dev) dev->mm = NULL; } +static void vhost_worker_free(struct vhost_dev *dev) +{ + struct vhost_worker *worker = dev->worker; + + if (!worker) + return; + + dev->worker = NULL; + WARN_ON(!llist_empty(&worker->work_list)); + kthread_stop(worker->task); + kfree(worker); +} + +static int vhost_worker_create(struct vhost_dev *dev) +{ + struct vhost_worker *worker; + struct task_struct *task; + int ret; + + worker = kzalloc(sizeof(*worker), GFP_KERNEL_ACCOUNT); + if (!worker) + return -ENOMEM; + + dev->worker = worker; + worker->dev = dev; + worker->kcov_handle = kcov_common_handle(); + init_llist_head(&worker->work_list); + + task = kthread_create(vhost_worker, worker, "vhost-%d", current->pid); + if (IS_ERR(task)) { + ret = PTR_ERR(task); + goto free_worker; + } + + worker->task = task; + wake_up_process(task); /* avoid contributing to loadavg */ + + ret = vhost_attach_cgroups(dev); + if (ret) + goto stop_worker; + + return 0; + +stop_worker: + kthread_stop(worker->task); +free_worker: + kfree(worker); + dev->worker = NULL; + return ret; +} + /* Caller should have device mutex */ long vhost_dev_set_owner(struct vhost_dev *dev) { - struct task_struct *worker; int err; /* Is there an owner already? */ @@ -585,36 +635,21 @@ long vhost_dev_set_owner(struct vhost_dev *dev) vhost_attach_mm(dev); - dev->kcov_handle = kcov_common_handle(); if (dev->use_worker) { - worker = kthread_create(vhost_worker, dev, - "vhost-%d", current->pid); - if (IS_ERR(worker)) { - err = PTR_ERR(worker); - goto err_worker; - } - - dev->worker = worker; - wake_up_process(worker); /* avoid contributing to loadavg */ - - err = vhost_attach_cgroups(dev); + err = vhost_worker_create(dev); if (err) - goto err_cgroup; + goto err_worker; } err = vhost_dev_alloc_iovecs(dev); if (err) - goto err_cgroup; + goto err_iovecs; return 0; -err_cgroup: - if (dev->worker) { - kthread_stop(dev->worker); - dev->worker = NULL; - } +err_iovecs: + vhost_worker_free(dev); err_worker: vhost_detach_mm(dev); - dev->kcov_handle = 0; err_mm: return err; } @@ -705,12 +740,7 @@ void vhost_dev_cleanup(struct vhost_dev *dev) dev->iotlb = NULL; vhost_clear_msg(dev); wake_up_interruptible_poll(&dev->wait, EPOLLIN | EPOLLRDNORM); - WARN_ON(!llist_empty(&dev->work_list)); - if (dev->worker) { - kthread_stop(dev->worker); - dev->worker = NULL; - dev->kcov_handle = 0; - } + vhost_worker_free(dev); vhost_detach_mm(dev); } EXPORT_SYMBOL_GPL(vhost_dev_cleanup); diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h index 1647b75..67d614b 100644 --- a/drivers/vhost/vhost.h +++ b/drivers/vhost/vhost.h @@ -25,6 +25,13 @@ struct vhost_work { unsigned long flags; }; +struct vhost_worker { + struct task_struct *task; + struct llist_head work_list; + struct vhost_dev *dev; + u64 kcov_handle; +}; + /* Poll a file (eventfd or socket) */ /* Note: there's nothing vhost specific about this structure. */ struct vhost_poll { @@ -147,8 +154,7 @@ struct vhost_dev { struct vhost_virtqueue **vqs; int nvqs; struct eventfd_ctx *log_ctx; - struct llist_head work_list; - struct task_struct *worker; + struct vhost_worker *worker; struct vhost_iotlb *umem; struct vhost_iotlb *iotlb; spinlock_t iotlb_lock; @@ -158,7 +164,6 @@ struct vhost_dev { int iov_limit; int weight; int byte_weight; - u64 kcov_handle; bool use_worker; int (*msg_handler)(struct vhost_dev *dev, u32 asid, struct vhost_iotlb_msg *msg);