From: Parav Pandit parav@nvidia.com
[ Upstream commit 0e566c8f0f2e8325e35f6f97e13cde5356b41814 ]
VQs may be accessed to mark the device broken while they are created/destroyed. Hence protect the access to the vqs list.
Fixes: e2dcdfe95c0b ("virtio: virtio_break_device() to mark all virtqueues broken.") Signed-off-by: Parav Pandit parav@nvidia.com Link: https://lore.kernel.org/r/20210721142648.1525924-4-parav@nvidia.com Signed-off-by: Michael S. Tsirkin mst@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/virtio/virtio.c | 1 + drivers/virtio/virtio_ring.c | 8 ++++++++ include/linux/virtio.h | 1 + 3 files changed, 10 insertions(+)
diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c index 42e09cc1b8ac..84b5dec5d29c 100644 --- a/drivers/virtio/virtio.c +++ b/drivers/virtio/virtio.c @@ -357,6 +357,7 @@ int register_virtio_device(struct virtio_device *dev) virtio_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE);
INIT_LIST_HEAD(&dev->vqs); + spin_lock_init(&dev->vqs_list_lock);
/* * device_add() causes the bus infrastructure to look for a matching diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index 71e16b53e9c1..6b7aa26c5384 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -1668,7 +1668,9 @@ static struct virtqueue *vring_create_virtqueue_packed( cpu_to_le16(vq->packed.event_flags_shadow); }
+ spin_lock(&vdev->vqs_list_lock); list_add_tail(&vq->vq.list, &vdev->vqs); + spin_unlock(&vdev->vqs_list_lock); return &vq->vq;
err_desc_extra: @@ -2126,7 +2128,9 @@ struct virtqueue *__vring_new_virtqueue(unsigned int index, memset(vq->split.desc_state, 0, vring.num * sizeof(struct vring_desc_state_split));
+ spin_lock(&vdev->vqs_list_lock); list_add_tail(&vq->vq.list, &vdev->vqs); + spin_unlock(&vdev->vqs_list_lock); return &vq->vq; } EXPORT_SYMBOL_GPL(__vring_new_virtqueue); @@ -2210,7 +2214,9 @@ void vring_del_virtqueue(struct virtqueue *_vq) } if (!vq->packed_ring) kfree(vq->split.desc_state); + spin_lock(&vq->vq.vdev->vqs_list_lock); list_del(&_vq->list); + spin_unlock(&vq->vq.vdev->vqs_list_lock); kfree(vq); } EXPORT_SYMBOL_GPL(vring_del_virtqueue); @@ -2274,10 +2280,12 @@ void virtio_break_device(struct virtio_device *dev) { struct virtqueue *_vq;
+ spin_lock(&dev->vqs_list_lock); list_for_each_entry(_vq, &dev->vqs, list) { struct vring_virtqueue *vq = to_vvq(_vq); vq->broken = true; } + spin_unlock(&dev->vqs_list_lock); } EXPORT_SYMBOL_GPL(virtio_break_device);
diff --git a/include/linux/virtio.h b/include/linux/virtio.h index 55ea329fe72a..8ecc2e208d61 100644 --- a/include/linux/virtio.h +++ b/include/linux/virtio.h @@ -110,6 +110,7 @@ struct virtio_device { bool config_enabled; bool config_change_pending; spinlock_t config_lock; + spinlock_t vqs_list_lock; /* Protects VQs list access */ struct device dev; struct virtio_device_id id; const struct virtio_config_ops *config;