vdpa/mlx5: support MTU feature

The guest virtio device may request MTU updating when the vhost backend
device exposes a capability to support it.

Expose the MTU feature capability.

At configuration time, check the requested MTU and update it in the HW
device.

Signed-off-by: Matan Azrad <matan@mellanox.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>

diff --git a/doc/guides/rel_notes/release_20_08.rst b/doc/guides/rel_notes/release_20_08.rst
index 97d8db1..8eb5662 100644 (file)
--- a/doc/guides/rel_notes/release_20_08.rst
+++ b/doc/guides/rel_notes/release_20_08.rst
@@ -78,6 +78,7 @@ New Features
   Updated Mellanox mlx5 vDPA driver with new features, including:
 
   * Added support for virtio queue statistics.
+  * Added support for MTU update.
 
 * **Added support for BPF_ABS/BPF_IND load instructions.**
 

diff --git a/doc/guides/vdpadevs/features/mlx5.ini b/doc/guides/vdpadevs/features/mlx5.ini
index 788d4e0..8bb9977 100644 (file)
--- a/doc/guides/vdpadevs/features/mlx5.ini
+++ b/doc/guides/vdpadevs/features/mlx5.ini
@@ -10,6 +10,7 @@ host tso4            = Y
 host tso6            = Y
 version 1            = Y
 log all              = Y
+mtu                  = Y
 any layout           = Y
 guest announce       = Y
 mq                   = Y

diff --git a/drivers/vdpa/mlx5/mlx5_vdpa.c b/drivers/vdpa/mlx5/mlx5_vdpa.c
index 94cac66..8b0b3b8 100644 (file)
--- a/drivers/vdpa/mlx5/mlx5_vdpa.c
+++ b/drivers/vdpa/mlx5/mlx5_vdpa.c
@@ -2,6 +2,11 @@
  * Copyright 2019 Mellanox Technologies, Ltd
  */
 #include <unistd.h>
+#include <net/if.h>
+#include <sys/socket.h>
+#include <sys/ioctl.h>
+#include <fcntl.h>
+#include <netinet/in.h>
 
 #include <rte_malloc.h>
 #include <rte_log.h>
@@ -25,14 +30,19 @@
                            (1ULL << VIRTIO_NET_F_MQ) | \
                            (1ULL << VIRTIO_NET_F_GUEST_ANNOUNCE) | \
                            (1ULL << VIRTIO_F_ORDER_PLATFORM) | \
-                           (1ULL << VHOST_F_LOG_ALL))
+                           (1ULL << VHOST_F_LOG_ALL) | \
+                           (1ULL << VIRTIO_NET_F_MTU))
 
 #define MLX5_VDPA_PROTOCOL_FEATURES \
                            ((1ULL << VHOST_USER_PROTOCOL_F_SLAVE_REQ) | \
                             (1ULL << VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD) | \
                             (1ULL << VHOST_USER_PROTOCOL_F_HOST_NOTIFIER) | \
                             (1ULL << VHOST_USER_PROTOCOL_F_LOG_SHMFD) | \
-                            (1ULL << VHOST_USER_PROTOCOL_F_MQ))
+                            (1ULL << VHOST_USER_PROTOCOL_F_MQ) | \
+                            (1ULL << VHOST_USER_PROTOCOL_F_NET_MTU))
+
+#define MLX5_VDPA_MAX_RETRIES 20
+#define MLX5_VDPA_USEC 1000
 
 TAILQ_HEAD(mlx5_vdpa_privs, mlx5_vdpa_priv) priv_list =
                                              TAILQ_HEAD_INITIALIZER(priv_list);
@@ -222,6 +232,55 @@ mlx5_vdpa_pd_create(struct mlx5_vdpa_priv *priv)
 #endif /* HAVE_IBV_FLOW_DV_SUPPORT */
 }
 
+static int
+mlx5_vdpa_mtu_set(struct mlx5_vdpa_priv *priv)
+{
+       struct ifreq request;
+       uint16_t vhost_mtu = 0;
+       uint16_t kern_mtu = 0;
+       int ret = rte_vhost_get_mtu(priv->vid, &vhost_mtu);
+       int sock;
+       int retries = MLX5_VDPA_MAX_RETRIES;
+
+       if (ret) {
+               DRV_LOG(DEBUG, "Cannot get vhost MTU - %d.", ret);
+               return ret;
+       }
+       if (!vhost_mtu) {
+               DRV_LOG(DEBUG, "Vhost MTU is 0.");
+               return ret;
+       }
+       ret = mlx5_get_ifname_sysfs(priv->ctx->device->ibdev_path,
+                                   request.ifr_name);
+       if (ret) {
+               DRV_LOG(DEBUG, "Cannot get kernel IF name - %d.", ret);
+               return ret;
+       }
+       sock = socket(PF_INET, SOCK_DGRAM, IPPROTO_IP);
+       if (sock == -1) {
+               DRV_LOG(DEBUG, "Cannot open IF socket.");
+               return sock;
+       }
+       while (retries--) {
+               ret = ioctl(sock, SIOCGIFMTU, &request);
+               if (ret == -1)
+                       break;
+               kern_mtu = request.ifr_mtu;
+               DRV_LOG(DEBUG, "MTU: current %d requested %d.", (int)kern_mtu,
+                       (int)vhost_mtu);
+               if (kern_mtu == vhost_mtu)
+                       break;
+               request.ifr_mtu = vhost_mtu;
+               ret = ioctl(sock, SIOCSIFMTU, &request);
+               if (ret == -1)
+                       break;
+               request.ifr_mtu = 0;
+               usleep(MLX5_VDPA_USEC);
+       }
+       close(sock);
+       return kern_mtu == vhost_mtu ? 0 : -1;
+}
+
 static int
 mlx5_vdpa_dev_close(int vid)
 {
@@ -265,6 +324,8 @@ mlx5_vdpa_dev_config(int vid)
                return -1;
        }
        priv->vid = vid;
+       if (mlx5_vdpa_mtu_set(priv))
+               DRV_LOG(WARNING, "MTU cannot be set on device %d.", did);
        if (mlx5_vdpa_pd_create(priv) || mlx5_vdpa_mem_register(priv) ||
            mlx5_vdpa_direct_db_prepare(priv) ||
            mlx5_vdpa_virtqs_prepare(priv) || mlx5_vdpa_steer_setup(priv) ||
@@ -513,8 +574,6 @@ close:
        return ret;
 }
 
-#define MLX5_VDPA_MAX_RETRIES 20
-#define MLX5_VDPA_USEC 1000
 static int
 mlx5_vdpa_roce_disable(struct rte_pci_addr *addr, struct ibv_device **ibv)
 {