Re: [RFC v4 02/11] vhost-vdpa: protect concurrent access to vhost device iotlb

[Jason Wang]

On 2021/2/23 7:50 下午, Xie Yongji wrote:

Use vhost_dev->mutex to protect vhost device iotlb from
concurrent access.

Fixes: 4c8cf318("vhost: introduce vDPA-based backend")
Signed-off-by: Xie Yongji <xieyon...@bytedance.com>
---
  drivers/vhost/vdpa.c | 2 ++
  1 file changed, 2 insertions(+)

diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
index c50079dfb281..5500e3bf05c1 100644
--- a/drivers/vhost/vdpa.c
+++ b/drivers/vhost/vdpa.c
@@ -723,6 +723,7 @@ static int vhost_vdpa_process_iotlb_msg(struct vhost_dev 
*dev,
        if (r)
                return r;

+ mutex_lock(&dev->mutex);

I think this should be done before the vhost_dev_check_owner() above.

Thanks

        switch (msg->type) {
        case VHOST_IOTLB_UPDATE:
                r = vhost_vdpa_process_iotlb_update(v, msg);
@@ -742,6 +743,7 @@ static int vhost_vdpa_process_iotlb_msg(struct vhost_dev 
*dev,
                r = -EINVAL;
                break;
        }
+       mutex_unlock(&dev->mutex);

return r;

  }