diff options
| author | Jean-Philippe Brucker <jean-philippe.brucker@arm.com> | 2018-11-30 16:05:53 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2018-12-03 15:52:30 -0800 |
| commit | e3f787189e10f5fafce77ba8aa948741ebb93c2b (patch) | |
| tree | 44b0e172af8f8621f15351aa2307642ba6fe25cf /drivers/vhost | |
| parent | 4763c9f926d8907beaacea4fd883c784696d84ef (diff) | |
| download | linux-e3f787189e10f5fafce77ba8aa948741ebb93c2b.tar.bz2 | |
vhost: fix IOTLB locking
Commit 78139c94dc8c ("net: vhost: lock the vqs one by one") moved the vq
lock to improve scalability, but introduced a possible deadlock in
vhost-iotlb. vhost_iotlb_notify_vq() now takes vq->mutex while holding
the device's IOTLB spinlock. And on the vhost_iotlb_miss() path, the
spinlock is taken while holding vq->mutex.
Since calling vhost_poll_queue() doesn't require any lock, avoid the
deadlock by not taking vq->mutex.
Fixes: 78139c94dc8c ("net: vhost: lock the vqs one by one")
Acked-by: Jason Wang <jasowang@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/vhost')
| -rw-r--r-- | drivers/vhost/vhost.c | 3 |
1 files changed, 0 insertions, 3 deletions
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index 3a5f81a66d34..6b98d8e3a5bf 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -944,10 +944,7 @@ static void vhost_iotlb_notify_vq(struct vhost_dev *d, if (msg->iova <= vq_msg->iova && msg->iova + msg->size - 1 >= vq_msg->iova && vq_msg->type == VHOST_IOTLB_MISS) { - mutex_lock(&node->vq->mutex); vhost_poll_queue(&node->vq->poll); - mutex_unlock(&node->vq->mutex); - list_del(&node->node); kfree(node); } |