Imported Upstream version 17.05

[deb_dpdk.git] / drivers / net / virtio / virtio_user / vhost_kernel_tap.c

diff --git a/drivers/net/virtio/virtio_user/vhost_kernel_tap.c b/drivers/net/virtio/virtio_user/vhost_kernel_tap.c
new file mode 100644 (file)
index 0000000..f585de8
--- /dev/null
+++ b/drivers/net/virtio/virtio_user/vhost_kernel_tap.c
@@ -0,0 +1,133 @@
+/*-
+ *   BSD LICENSE
+ *
+ *   Copyright(c) 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.
+ */
+
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <net/if.h>
+#include <errno.h>
+#include <string.h>
+#include <limits.h>
+
+#include "vhost_kernel_tap.h"
+#include "../virtio_logs.h"
+
+int
+vhost_kernel_open_tap(char **p_ifname, int hdr_size, int req_mq)
+{
+       unsigned int tap_features;
+       int sndbuf = INT_MAX;
+       struct ifreq ifr;
+       int tapfd;
+       unsigned int offload =
+                       TUN_F_CSUM |
+                       TUN_F_TSO4 |
+                       TUN_F_TSO6 |
+                       TUN_F_TSO_ECN |
+                       TUN_F_UFO;
+
+       /* TODO:
+        * 1. verify we can get/set vnet_hdr_len, tap_probe_vnet_hdr_len
+        * 2. get number of memory regions from vhost module parameter
+        * max_mem_regions, supported in newer version linux kernel
+        */
+       tapfd = open(PATH_NET_TUN, O_RDWR);
+       if (tapfd < 0) {
+               PMD_DRV_LOG(ERR, "fail to open %s: %s",
+                           PATH_NET_TUN, strerror(errno));
+               return -1;
+       }
+
+       /* Construct ifr */
+       memset(&ifr, 0, sizeof(ifr));
+       ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
+
+       if (ioctl(tapfd, TUNGETFEATURES, &tap_features) == -1) {
+               PMD_DRV_LOG(ERR, "TUNGETFEATURES failed: %s", strerror(errno));
+               goto error;
+       }
+       if (tap_features & IFF_ONE_QUEUE)
+               ifr.ifr_flags |= IFF_ONE_QUEUE;
+
+       /* Let tap instead of vhost-net handle vnet header, as the latter does
+        * not support offloading. And in this case, we should not set feature
+        * bit VHOST_NET_F_VIRTIO_NET_HDR.
+        */
+       if (tap_features & IFF_VNET_HDR) {
+               ifr.ifr_flags |= IFF_VNET_HDR;
+       } else {
+               PMD_DRV_LOG(ERR, "TAP does not support IFF_VNET_HDR");
+               goto error;
+       }
+
+       if (req_mq)
+               ifr.ifr_flags |= IFF_MULTI_QUEUE;
+
+       if (*p_ifname)
+               strncpy(ifr.ifr_name, *p_ifname, IFNAMSIZ);
+       else
+               strncpy(ifr.ifr_name, "tap%d", IFNAMSIZ);
+       if (ioctl(tapfd, TUNSETIFF, (void *)&ifr) == -1) {
+               PMD_DRV_LOG(ERR, "TUNSETIFF failed: %s", strerror(errno));
+               goto error;
+       }
+
+       fcntl(tapfd, F_SETFL, O_NONBLOCK);
+
+       if (ioctl(tapfd, TUNSETVNETHDRSZ, &hdr_size) < 0) {
+               PMD_DRV_LOG(ERR, "TUNSETVNETHDRSZ failed: %s", strerror(errno));
+               goto error;
+       }
+
+       if (ioctl(tapfd, TUNSETSNDBUF, &sndbuf) < 0) {
+               PMD_DRV_LOG(ERR, "TUNSETSNDBUF failed: %s", strerror(errno));
+               goto error;
+       }
+
+       /* TODO: before set the offload capabilities, we'd better (1) check
+        * negotiated features to see if necessary to offload; (2) query tap
+        * to see if it supports the offload capabilities.
+        */
+       if (ioctl(tapfd, TUNSETOFFLOAD, offload) != 0)
+               PMD_DRV_LOG(ERR, "TUNSETOFFLOAD ioctl() failed: %s",
+                          strerror(errno));
+
+       if (!(*p_ifname))
+               *p_ifname = strdup(ifr.ifr_name);
+
+       return tapfd;
+error:
+       close(tapfd);
+       return -1;
+}