diff options
| -rw-r--r-- | drivers/vfio/vfio.c | 41 | ||||
| -rw-r--r-- | drivers/vfio/vfio.h | 12 | ||||
| -rw-r--r-- | drivers/vfio/vfio_iommu_type1.c | 103 | ||||
| -rw-r--r-- | include/linux/vfio.h | 2 |
4 files changed, 81 insertions, 77 deletions
diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c index 83c375fa2421..b3ce8073cfb1 100644 --- a/drivers/vfio/vfio.c +++ b/drivers/vfio/vfio.c @@ -231,7 +231,7 @@ int vfio_register_iommu_driver(const struct vfio_iommu_driver_ops *ops) { struct vfio_iommu_driver *driver, *tmp; - if (WARN_ON(!ops->register_notifier != !ops->unregister_notifier)) + if (WARN_ON(!ops->register_device != !ops->unregister_device)) return -EINVAL; driver = kzalloc(sizeof(*driver), GFP_KERNEL); @@ -1082,17 +1082,6 @@ static void vfio_device_unassign_container(struct vfio_device *device) up_write(&device->group->group_rwsem); } -static int vfio_iommu_notifier(struct notifier_block *nb, unsigned long action, - void *data) -{ - struct vfio_device *vfio_device = - container_of(nb, struct vfio_device, iommu_nb); - struct vfio_iommu_type1_dma_unmap *unmap = data; - - vfio_device->ops->dma_unmap(vfio_device, unmap->iova, unmap->size); - return NOTIFY_OK; -} - static struct file *vfio_device_open(struct vfio_device *device) { struct vfio_iommu_driver *iommu_driver; @@ -1128,15 +1117,9 @@ static struct file *vfio_device_open(struct vfio_device *device) } iommu_driver = device->group->container->iommu_driver; - if (device->ops->dma_unmap && iommu_driver && - iommu_driver->ops->register_notifier) { - unsigned long events = VFIO_IOMMU_NOTIFY_DMA_UNMAP; - - device->iommu_nb.notifier_call = vfio_iommu_notifier; - iommu_driver->ops->register_notifier( - device->group->container->iommu_data, &events, - &device->iommu_nb); - } + if (iommu_driver && iommu_driver->ops->register_device) + iommu_driver->ops->register_device( + device->group->container->iommu_data, device); up_read(&device->group->group_rwsem); } @@ -1176,11 +1159,9 @@ err_close_device: device->ops->close_device(device); iommu_driver = device->group->container->iommu_driver; - if (device->ops->dma_unmap && iommu_driver && - iommu_driver->ops->unregister_notifier) - iommu_driver->ops->unregister_notifier( - device->group->container->iommu_data, - &device->iommu_nb); + if (iommu_driver && iommu_driver->ops->unregister_device) + iommu_driver->ops->unregister_device( + device->group->container->iommu_data, device); } err_undo_count: up_read(&device->group->group_rwsem); @@ -1385,11 +1366,9 @@ static int vfio_device_fops_release(struct inode *inode, struct file *filep) device->ops->close_device(device); iommu_driver = device->group->container->iommu_driver; - if (device->ops->dma_unmap && iommu_driver && - iommu_driver->ops->unregister_notifier) - iommu_driver->ops->unregister_notifier( - device->group->container->iommu_data, - &device->iommu_nb); + if (iommu_driver && iommu_driver->ops->unregister_device) + iommu_driver->ops->unregister_device( + device->group->container->iommu_data, device); up_read(&device->group->group_rwsem); device->open_count--; if (device->open_count == 0) diff --git a/drivers/vfio/vfio.h b/drivers/vfio/vfio.h index 25da02ca1568..4a7db1f3c33e 100644 --- a/drivers/vfio/vfio.h +++ b/drivers/vfio/vfio.h @@ -33,9 +33,6 @@ enum vfio_iommu_notify_type { VFIO_IOMMU_CONTAINER_CLOSE = 0, }; -/* events for register_notifier() */ -#define VFIO_IOMMU_NOTIFY_DMA_UNMAP BIT(0) - /** * struct vfio_iommu_driver_ops - VFIO IOMMU driver callbacks */ @@ -58,11 +55,10 @@ struct vfio_iommu_driver_ops { unsigned long *phys_pfn); int (*unpin_pages)(void *iommu_data, unsigned long *user_pfn, int npage); - int (*register_notifier)(void *iommu_data, - unsigned long *events, - struct notifier_block *nb); - int (*unregister_notifier)(void *iommu_data, - struct notifier_block *nb); + void (*register_device)(void *iommu_data, + struct vfio_device *vdev); + void (*unregister_device)(void *iommu_data, + struct vfio_device *vdev); int (*dma_rw)(void *iommu_data, dma_addr_t user_iova, void *data, size_t count, bool write); struct iommu_domain *(*group_iommu_domain)(void *iommu_data, diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c index db24062fb343..026a1d2553a2 100644 --- a/drivers/vfio/vfio_iommu_type1.c +++ b/drivers/vfio/vfio_iommu_type1.c @@ -67,7 +67,8 @@ struct vfio_iommu { struct list_head iova_list; struct mutex lock; struct rb_root dma_list; - struct blocking_notifier_head notifier; + struct list_head device_list; + struct mutex device_list_lock; unsigned int dma_avail; unsigned int vaddr_invalid_count; uint64_t pgsize_bitmap; @@ -865,8 +866,8 @@ again: } } - /* Fail if notifier list is empty */ - if (!iommu->notifier.head) { + /* Fail if no dma_umap notifier is registered */ + if (list_empty(&iommu->device_list)) { ret = -EINVAL; goto pin_done; } @@ -1287,6 +1288,35 @@ static int verify_bitmap_size(uint64_t npages, uint64_t bitmap_size) return 0; } +/* + * Notify VFIO drivers using vfio_register_emulated_iommu_dev() to invalidate + * and unmap iovas within the range we're about to unmap. Drivers MUST unpin + * pages in response to an invalidation. + */ +static void vfio_notify_dma_unmap(struct vfio_iommu *iommu, + struct vfio_dma *dma) +{ + struct vfio_device *device; + + if (list_empty(&iommu->device_list)) + return; + + /* + * The device is expected to call vfio_unpin_pages() for any IOVA it has + * pinned within the range. Since vfio_unpin_pages() will eventually + * call back down to this code and try to obtain the iommu->lock we must + * drop it. + */ + mutex_lock(&iommu->device_list_lock); + mutex_unlock(&iommu->lock); + + list_for_each_entry(device, &iommu->device_list, iommu_entry) + device->ops->dma_unmap(device, dma->iova, dma->size); + + mutex_unlock(&iommu->device_list_lock); + mutex_lock(&iommu->lock); +} + static int vfio_dma_do_unmap(struct vfio_iommu *iommu, struct vfio_iommu_type1_dma_unmap *unmap, struct vfio_bitmap *bitmap) @@ -1400,8 +1430,6 @@ again: } if (!RB_EMPTY_ROOT(&dma->pfn_list)) { - struct vfio_iommu_type1_dma_unmap nb_unmap; - if (dma_last == dma) { BUG_ON(++retries > 10); } else { @@ -1409,20 +1437,7 @@ again: retries = 0; } - nb_unmap.iova = dma->iova; - nb_unmap.size = dma->size; - - /* - * Notify anyone (mdev vendor drivers) to invalidate and - * unmap iovas within the range we're about to unmap. - * Vendor drivers MUST unpin pages in response to an - * invalidation. - */ - mutex_unlock(&iommu->lock); - blocking_notifier_call_chain(&iommu->notifier, - VFIO_IOMMU_NOTIFY_DMA_UNMAP, - &nb_unmap); - mutex_lock(&iommu->lock); + vfio_notify_dma_unmap(iommu, dma); goto again; } @@ -2475,7 +2490,7 @@ static void vfio_iommu_type1_detach_group(void *iommu_data, if (list_empty(&iommu->emulated_iommu_groups) && list_empty(&iommu->domain_list)) { - WARN_ON(iommu->notifier.head); + WARN_ON(!list_empty(&iommu->device_list)); vfio_iommu_unmap_unpin_all(iommu); } goto detach_group_done; @@ -2507,7 +2522,8 @@ static void vfio_iommu_type1_detach_group(void *iommu_data, if (list_empty(&domain->group_list)) { if (list_is_singular(&iommu->domain_list)) { if (list_empty(&iommu->emulated_iommu_groups)) { - WARN_ON(iommu->notifier.head); + WARN_ON(!list_empty( + &iommu->device_list)); vfio_iommu_unmap_unpin_all(iommu); } else { vfio_iommu_unmap_unpin_reaccount(iommu); @@ -2568,7 +2584,8 @@ static void *vfio_iommu_type1_open(unsigned long arg) iommu->dma_avail = dma_entry_limit; iommu->container_open = true; mutex_init(&iommu->lock); - BLOCKING_INIT_NOTIFIER_HEAD(&iommu->notifier); + mutex_init(&iommu->device_list_lock); + INIT_LIST_HEAD(&iommu->device_list); init_waitqueue_head(&iommu->vaddr_wait); iommu->pgsize_bitmap = PAGE_MASK; INIT_LIST_HEAD(&iommu->emulated_iommu_groups); @@ -3005,28 +3022,40 @@ static long vfio_iommu_type1_ioctl(void *iommu_data, } } -static int vfio_iommu_type1_register_notifier(void *iommu_data, - unsigned long *events, - struct notifier_block *nb) +static void vfio_iommu_type1_register_device(void *iommu_data, + struct vfio_device *vdev) { struct vfio_iommu *iommu = iommu_data; - /* clear known events */ - *events &= ~VFIO_IOMMU_NOTIFY_DMA_UNMAP; - - /* refuse to register if still events remaining */ - if (*events) - return -EINVAL; + if (!vdev->ops->dma_unmap) + return; - return blocking_notifier_chain_register(&iommu->notifier, nb); + /* + * list_empty(&iommu->device_list) is tested under the iommu->lock while + * iteration for dma_unmap must be done under the device_list_lock. + * Holding both locks here allows avoiding the device_list_lock in + * several fast paths. See vfio_notify_dma_unmap() + */ + mutex_lock(&iommu->lock); + mutex_lock(&iommu->device_list_lock); + list_add(&vdev->iommu_entry, &iommu->device_list); + mutex_unlock(&iommu->device_list_lock); + mutex_unlock(&iommu->lock); } -static int vfio_iommu_type1_unregister_notifier(void *iommu_data, - struct notifier_block *nb) +static void vfio_iommu_type1_unregister_device(void *iommu_data, + struct vfio_device *vdev) { struct vfio_iommu *iommu = iommu_data; - return blocking_notifier_chain_unregister(&iommu->notifier, nb); + if (!vdev->ops->dma_unmap) + return; + + mutex_lock(&iommu->lock); + mutex_lock(&iommu->device_list_lock); + list_del(&vdev->iommu_entry); + mutex_unlock(&iommu->device_list_lock); + mutex_unlock(&iommu->lock); } static int vfio_iommu_type1_dma_rw_chunk(struct vfio_iommu *iommu, @@ -3160,8 +3189,8 @@ static const struct vfio_iommu_driver_ops vfio_iommu_driver_ops_type1 = { .detach_group = vfio_iommu_type1_detach_group, .pin_pages = vfio_iommu_type1_pin_pages, .unpin_pages = vfio_iommu_type1_unpin_pages, - .register_notifier = vfio_iommu_type1_register_notifier, - .unregister_notifier = vfio_iommu_type1_unregister_notifier, + .register_device = vfio_iommu_type1_register_device, + .unregister_device = vfio_iommu_type1_unregister_device, .dma_rw = vfio_iommu_type1_dma_rw, .group_iommu_domain = vfio_iommu_type1_group_iommu_domain, .notify = vfio_iommu_type1_notify, diff --git a/include/linux/vfio.h b/include/linux/vfio.h index 1f9fc7a9be9e..19cefbaa3d06 100644 --- a/include/linux/vfio.h +++ b/include/linux/vfio.h @@ -49,7 +49,7 @@ struct vfio_device { unsigned int open_count; struct completion comp; struct list_head group_next; - struct notifier_block iommu_nb; + struct list_head iommu_entry; }; /** |