lib: use SPDX tag for Intel copyright files

[dpdk.git] / lib / librte_vhost / vhost.c

diff --git a/lib/librte_vhost/vhost.c b/lib/librte_vhost/vhost.c
index 54a1864..a93c70d 100644 (file)
--- a/lib/librte_vhost/vhost.c
+++ b/lib/librte_vhost/vhost.c
@@ -1,34 +1,5 @@
-/*-
- *   BSD LICENSE
- *
- *   Copyright(c) 2010-2016 Intel Corporation. All rights reserved.
- *   All rights reserved.
- *
- *   Redistribution and use in source and binary forms, with or without
- *   modification, are permitted provided that the following conditions
- *   are met:
- *
- *     * Redistributions of source code must retain the above copyright
- *       notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above copyright
- *       notice, this list of conditions and the following disclaimer in
- *       the documentation and/or other materials provided with the
- *       distribution.
- *     * Neither the name of Intel Corporation nor the names of its
- *       contributors may be used to endorse or promote products derived
- *       from this software without specific prior written permission.
- *
- *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2010-2016 Intel Corporation
  */
 
 #include <linux/vhost.h>
@@ -55,6 +26,7 @@
 
 struct virtio_net *vhost_devices[MAX_VHOST_DEVICE];
 
+/* Called with iotlb_lock read-locked */
 uint64_t
 __vhost_iova_to_vva(struct virtio_net *dev, struct vhost_virtqueue *vq,
                    uint64_t iova, uint64_t size, uint8_t perm)
@@ -71,8 +43,19 @@ __vhost_iova_to_vva(struct virtio_net *dev, struct vhost_virtqueue *vq,
                return vva;
 
        if (!vhost_user_iotlb_pending_miss(vq, iova + tmp_size, perm)) {
+               /*
+                * iotlb_lock is read-locked for a full burst,
+                * but it only protects the iotlb cache.
+                * In case of IOTLB miss, we might block on the socket,
+                * which could cause a deadlock with QEMU if an IOTLB update
+                * is being handled. We can safely unlock here to avoid it.
+                */
+               vhost_user_iotlb_rd_unlock(vq);
+
                vhost_user_iotlb_pending_insert(vq, iova + tmp_size, perm);
                vhost_user_iotlb_miss(dev, iova + tmp_size, perm);
+
+               vhost_user_iotlb_rd_lock(vq);
        }
 
        return 0;