diff options
Diffstat (limited to 'drivers/vhost/vhost.c')
-rw-r--r-- | drivers/vhost/vhost.c | 142 |
1 files changed, 141 insertions, 1 deletions
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index ffbaf7d32e2c..bfba91ecbd0a 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -626,6 +626,76 @@ free_worker: return NULL; } +/* Caller must have device mutex */ +static void __vhost_vq_attach_worker(struct vhost_virtqueue *vq, + struct vhost_worker *worker) +{ + if (vq->worker) + vq->worker->attachment_cnt--; + worker->attachment_cnt++; + vq->worker = worker; +} + + /* Caller must have device and virtqueue mutex */ +static int vhost_vq_attach_worker(struct vhost_virtqueue *vq, + struct vhost_vring_worker *info) +{ + unsigned long index = info->worker_id; + struct vhost_dev *dev = vq->dev; + struct vhost_worker *worker; + + if (!dev->use_worker) + return -EINVAL; + + /* + * We only allow userspace to set a virtqueue's worker if it's not + * active and polling is not enabled. We also assume drivers + * supporting this will not be internally queueing works directly or + * via calls like vhost_dev_flush at this time. + */ + if (vhost_vq_get_backend(vq) || vq->kick) + return -EBUSY; + + worker = xa_find(&dev->worker_xa, &index, UINT_MAX, XA_PRESENT); + if (!worker || worker->id != info->worker_id) + return -ENODEV; + + __vhost_vq_attach_worker(vq, worker); + return 0; +} + +/* Caller must have device mutex */ +static int vhost_new_worker(struct vhost_dev *dev, + struct vhost_worker_state *info) +{ + struct vhost_worker *worker; + + worker = vhost_worker_create(dev); + if (!worker) + return -ENOMEM; + + info->worker_id = worker->id; + return 0; +} + +/* Caller must have device mutex */ +static int vhost_free_worker(struct vhost_dev *dev, + struct vhost_worker_state *info) +{ + unsigned long index = info->worker_id; + struct vhost_worker *worker; + + worker = xa_find(&dev->worker_xa, &index, UINT_MAX, XA_PRESENT); + if (!worker || worker->id != info->worker_id) + return -ENODEV; + + if (worker->attachment_cnt) + return -EBUSY; + + vhost_worker_destroy(dev, worker); + return 0; +} + static int vhost_get_vq_from_user(struct vhost_dev *dev, void __user *argp, struct vhost_virtqueue **vq, u32 *id) { @@ -647,6 +717,76 @@ static int vhost_get_vq_from_user(struct vhost_dev *dev, void __user *argp, return 0; } +/* Caller must have device mutex */ +long vhost_worker_ioctl(struct vhost_dev *dev, unsigned int ioctl, + void __user *argp) +{ + struct vhost_vring_worker ring_worker; + struct vhost_worker_state state; + struct vhost_virtqueue *vq; + long ret; + u32 idx; + + if (!dev->use_worker) + return -EINVAL; + + if (!vhost_dev_has_owner(dev)) + return -EINVAL; + + ret = vhost_dev_check_owner(dev); + if (ret) + return ret; + + switch (ioctl) { + /* dev worker ioctls */ + case VHOST_NEW_WORKER: + ret = vhost_new_worker(dev, &state); + if (!ret && copy_to_user(argp, &state, sizeof(state))) + ret = -EFAULT; + return ret; + case VHOST_FREE_WORKER: + if (copy_from_user(&state, argp, sizeof(state))) + return -EFAULT; + return vhost_free_worker(dev, &state); + /* vring worker ioctls */ + case VHOST_ATTACH_VRING_WORKER: + case VHOST_GET_VRING_WORKER: + break; + default: + return -ENOIOCTLCMD; + } + + ret = vhost_get_vq_from_user(dev, argp, &vq, &idx); + if (ret) + return ret; + + mutex_lock(&vq->mutex); + switch (ioctl) { + case VHOST_ATTACH_VRING_WORKER: + if (copy_from_user(&ring_worker, argp, sizeof(ring_worker))) { + ret = -EFAULT; + break; + } + + ret = vhost_vq_attach_worker(vq, &ring_worker); + break; + case VHOST_GET_VRING_WORKER: + ring_worker.index = idx; + ring_worker.worker_id = vq->worker->id; + + if (copy_to_user(argp, &ring_worker, sizeof(ring_worker))) + ret = -EFAULT; + break; + default: + ret = -ENOIOCTLCMD; + break; + } + + mutex_unlock(&vq->mutex); + return ret; +} +EXPORT_SYMBOL_GPL(vhost_worker_ioctl); + /* Caller should have device mutex */ long vhost_dev_set_owner(struct vhost_dev *dev) { @@ -684,7 +824,7 @@ long vhost_dev_set_owner(struct vhost_dev *dev) smp_wmb(); for (i = 0; i < dev->nvqs; i++) - dev->vqs[i]->worker = worker; + __vhost_vq_attach_worker(dev->vqs[i], worker); } return 0; |