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 <pa...@nvidia.com> --- changelog: v1->v2: - use the hole in current struct to place vqs_list_lock to have natural packing v0->v1: - use spinlock instead of rwlock --- 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 4b15c00c0a0a..49984d2cba24 100644 --- a/drivers/virtio/virtio.c +++ b/drivers/virtio/virtio.c @@ -355,6 +355,7 @@ 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 d5934c2e5a89..c2aaa0eff6df 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -1755,7 +1755,9 @@ 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: @@ -2229,7 +2231,9 @@ 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; err_extra: @@ -2291,7 +2295,9 @@ void vring_del_virtqueue(struct virtqueue *_vq) { struct vring_virtqueue *vq = to_vvq(_vq); + spin_lock(&vq->vq.vdev->vqs_list_lock); list_del(&_vq->list); + spin_unlock(&vq->vq.vdev->vqs_list_lock); if (vq->we_own_ring) { if (vq->packed_ring) { @@ -2386,12 +2392,14 @@ 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); /* Pairs with READ_ONCE() in virtqueue_is_broken(). */ WRITE_ONCE(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 b1894e0323fa..41edbc01ffa4 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; -- 2.27.0 _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization