Re: [PATCH v6 03/10] vhost-vdpa: protect concurrent access to vhost device iotlb
From: "Michael S. Tsirkin" <mst@redhat.com>
Date: 2021-04-09 16:16:02
Also in:
kvm, linux-fsdevel, virtualization
On Wed, Mar 31, 2021 at 04:05:12PM +0800, Xie Yongji wrote:
Use vhost_dev->mutex to protect vhost device iotlb from
concurrent access.
Fixes: 4c8cf318("vhost: introduce vDPA-based backend")
Cc: stable@vger.kernel.org
Signed-off-by: Xie Yongji <redacted>
Acked-by: Jason Wang <redacted>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>I could not figure out whether there's a bug there now. If yes when is the concurrent access triggered?
quoted hunk ↗ jump to hunk
--- drivers/vhost/vdpa.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c index 3947fbc2d1d5..63b28d3aee7c 100644 --- a/drivers/vhost/vdpa.c +++ b/drivers/vhost/vdpa.c@@ -725,9 +725,11 @@ static int vhost_vdpa_process_iotlb_msg(struct vhost_dev *dev, const struct vdpa_config_ops *ops = vdpa->config; int r = 0; + mutex_lock(&dev->mutex); + r = vhost_dev_check_owner(dev); if (r) - return r; + goto unlock; switch (msg->type) { case VHOST_IOTLB_UPDATE:@@ -748,6 +750,8 @@ static int vhost_vdpa_process_iotlb_msg(struct vhost_dev *dev, r = -EINVAL; break; } +unlock: + mutex_unlock(&dev->mutex); return r; }-- 2.11.0