diff options
Diffstat (limited to 'drivers/vhost/vhost.c')
| -rw-r--r-- | drivers/vhost/vhost.c | 98 |
1 files changed, 68 insertions, 30 deletions
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index 596132a96cd5..062595ee1f83 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -166,11 +166,16 @@ static int vhost_poll_wakeup(wait_queue_entry_t *wait, unsigned mode, int sync, void *key) { struct vhost_poll *poll = container_of(wait, struct vhost_poll, wait); + struct vhost_work *work = &poll->work; if (!(key_to_poll(key) & poll->mask)) return 0; - vhost_poll_queue(poll); + if (!poll->dev->use_worker) + work->fn(work); + else + vhost_poll_queue(poll); + return 0; } @@ -454,6 +459,7 @@ static size_t vhost_get_desc_size(struct vhost_virtqueue *vq, void vhost_dev_init(struct vhost_dev *dev, struct vhost_virtqueue **vqs, int nvqs, int iov_limit, int weight, int byte_weight, + bool use_worker, int (*msg_handler)(struct vhost_dev *dev, struct vhost_iotlb_msg *msg)) { @@ -471,6 +477,7 @@ void vhost_dev_init(struct vhost_dev *dev, dev->iov_limit = iov_limit; dev->weight = weight; 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); @@ -534,6 +541,36 @@ bool vhost_dev_has_owner(struct vhost_dev *dev) } EXPORT_SYMBOL_GPL(vhost_dev_has_owner); +static void vhost_attach_mm(struct vhost_dev *dev) +{ + /* No owner, become one */ + if (dev->use_worker) { + dev->mm = get_task_mm(current); + } else { + /* vDPA device does not use worker thead, so there's + * no need to hold the address space for mm. This help + * to avoid deadlock in the case of mmap() which may + * held the refcnt of the file and depends on release + * method to remove vma. + */ + dev->mm = current->mm; + mmgrab(dev->mm); + } +} + +static void vhost_detach_mm(struct vhost_dev *dev) +{ + if (!dev->mm) + return; + + if (dev->use_worker) + mmput(dev->mm); + else + mmdrop(dev->mm); + + dev->mm = NULL; +} + /* Caller should have device mutex */ long vhost_dev_set_owner(struct vhost_dev *dev) { @@ -546,21 +583,24 @@ long vhost_dev_set_owner(struct vhost_dev *dev) goto err_mm; } - /* No owner, become one */ - dev->mm = get_task_mm(current); + vhost_attach_mm(dev); + dev->kcov_handle = kcov_common_handle(); - worker = kthread_create(vhost_worker, dev, "vhost-%d", current->pid); - if (IS_ERR(worker)) { - err = PTR_ERR(worker); - goto err_worker; - } + 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 */ + dev->worker = worker; + wake_up_process(worker); /* avoid contributing to loadavg */ - err = vhost_attach_cgroups(dev); - if (err) - goto err_cgroup; + err = vhost_attach_cgroups(dev); + if (err) + goto err_cgroup; + } err = vhost_dev_alloc_iovecs(dev); if (err) @@ -568,12 +608,12 @@ long vhost_dev_set_owner(struct vhost_dev *dev) return 0; err_cgroup: - kthread_stop(worker); - dev->worker = NULL; + if (dev->worker) { + kthread_stop(dev->worker); + dev->worker = NULL; + } err_worker: - if (dev->mm) - mmput(dev->mm); - dev->mm = NULL; + vhost_detach_mm(dev); dev->kcov_handle = 0; err_mm: return err; @@ -670,9 +710,7 @@ void vhost_dev_cleanup(struct vhost_dev *dev) dev->worker = NULL; dev->kcov_handle = 0; } - if (dev->mm) - mmput(dev->mm); - dev->mm = NULL; + vhost_detach_mm(dev); } EXPORT_SYMBOL_GPL(vhost_dev_cleanup); @@ -882,7 +920,7 @@ static inline void __user *__vhost_get_user(struct vhost_virtqueue *vq, #define vhost_put_user(vq, x, ptr) \ ({ \ - int ret = -EFAULT; \ + int ret; \ if (!vq->iotlb) { \ ret = __put_user(x, ptr); \ } else { \ @@ -1244,9 +1282,9 @@ static int vhost_iotlb_miss(struct vhost_virtqueue *vq, u64 iova, int access) } static bool vq_access_ok(struct vhost_virtqueue *vq, unsigned int num, - struct vring_desc __user *desc, - struct vring_avail __user *avail, - struct vring_used __user *used) + vring_desc_t __user *desc, + vring_avail_t __user *avail, + vring_used_t __user *used) { return access_ok(desc, vhost_get_desc_size(vq, num)) && @@ -1574,7 +1612,7 @@ long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *arg r = -EFAULT; break; } - eventfp = f.fd == -1 ? NULL : eventfd_fget(f.fd); + eventfp = f.fd == VHOST_FILE_UNBIND ? NULL : eventfd_fget(f.fd); if (IS_ERR(eventfp)) { r = PTR_ERR(eventfp); break; @@ -1590,7 +1628,7 @@ long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *arg r = -EFAULT; break; } - ctx = f.fd == -1 ? NULL : eventfd_ctx_fdget(f.fd); + ctx = f.fd == VHOST_FILE_UNBIND ? NULL : eventfd_ctx_fdget(f.fd); if (IS_ERR(ctx)) { r = PTR_ERR(ctx); break; @@ -1602,7 +1640,7 @@ long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *arg r = -EFAULT; break; } - ctx = f.fd == -1 ? NULL : eventfd_ctx_fdget(f.fd); + ctx = f.fd == VHOST_FILE_UNBIND ? NULL : eventfd_ctx_fdget(f.fd); if (IS_ERR(ctx)) { r = PTR_ERR(ctx); break; @@ -1727,7 +1765,7 @@ long vhost_dev_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp) r = get_user(fd, (int __user *)argp); if (r < 0) break; - ctx = fd == -1 ? NULL : eventfd_ctx_fdget(fd); + ctx = fd == VHOST_FILE_UNBIND ? NULL : eventfd_ctx_fdget(fd); if (IS_ERR(ctx)) { r = PTR_ERR(ctx); break; @@ -2300,7 +2338,7 @@ static int __vhost_add_used_n(struct vhost_virtqueue *vq, struct vring_used_elem *heads, unsigned count) { - struct vring_used_elem __user *used; + vring_used_elem_t __user *used; u16 old, new; int start; |