[ovs-dev,v3] netdev-dpdk: add hotplug support

diff --git a/INSTALL.DPDK.md b/INSTALL.DPDK.md
index 9ec8bf6..4095402 100644
--- a/INSTALL.DPDK.md
+++ b/INSTALL.DPDK.md
@@ -81,7 +81,7 @@  Using the DPDK with ovs-vswitchd:
 
 1. Setup system boot
    Add the following options to the kernel bootline:
-   
+
    `default_hugepagesz=1GB hugepagesz=1G hugepages=1`
 
 2. Setup DPDK devices:
@@ -227,6 +227,29 @@  Using the DPDK with ovs-vswitchd:
    For more details regarding egress-policer parameters please refer to the
    vswitch.xml.
 
+9. Port Hotplug
+
+   ovs supports port hotplugging, it allows to use ports that were not bound
+   to DPDK when vswitchd was started.
+   In order to attach a port, it has to be bound to DPDK using the
+   dpdk_nic_bind.py script:
+
+   `$DPDK_DIR/tools/dpdk_nic_bind.py --bind=igb_uio 0000:01:00.0`
+
+   Then it can be attached to OVS:
+
+   `ovs-appctl netdev-dpdk/port-ctl attach 0000:01:00.0`
+
+   At this point, the user can create a ovs port using the add-port command.
+
+   It is also possible to detach a port from ovs, the user has to remove the
+   port using the del-port command, then it can be detached using:
+
+   `ovs-appctl netdev-dpdk/port-ctl detach dpdk0`
+
+   This feature is not supported by all the NICs, please refer to the
+   [DPDK Port Hotplug Framework] in order to get more information.
+
 Performance Tuning:
 -------------------
 
@@ -959,3 +982,4 @@  Please report problems to bugs@openvswitch.org.
 [INSTALL.md]:INSTALL.md
 [DPDK Linux GSG]: http://www.dpdk.org/doc/guides/linux_gsg/build_dpdk.html#binding-and-unbinding-network-ports-to-from-the-igb-uioor-vfio-modules
 [DPDK Docs]: http://dpdk.org/doc
+[DPDK Port Hotplug Framework]: http://dpdk.org/doc/guides/prog_guide/port_hotplug_framework.html
diff --git a/NEWS b/NEWS
index ea7f3a1..2ba8659 100644
--- a/NEWS
+++ b/NEWS
@@ -26,6 +26,7 @@  Post-v2.5.0
        assignment.
      * Type of log messages from PMD threads changed from INFO to DBG.
      * QoS functionality with sample egress-policer implementation.
+     * Port Hotplug is now supported.
    - ovs-benchmark: This utility has been removed due to lack of use and
      bitrot.
    - ovs-appctl:
diff --git a/lib/netdev-dpdk.c b/lib/netdev-dpdk.c
index e09b471..cd98a2b 100644
--- a/lib/netdev-dpdk.c
+++ b/lib/netdev-dpdk.c
@@ -599,7 +599,7 @@  dpdk_eth_dev_init(struct netdev_dpdk *dev) OVS_REQUIRES(dpdk_mutex)
     int diag;
     int n_rxq, n_txq;
 
-    if (dev->port_id < 0 || dev->port_id >= rte_eth_dev_count()) {
+    if (!rte_eth_dev_is_valid_port(dev->port_id)) {
         return ENODEV;
     }
 
@@ -1985,6 +1985,89 @@  netdev_dpdk_set_admin_state(struct unixctl_conn *conn, int argc,
     unixctl_command_reply(conn, "OK");
 }
 
+static int
+dpdk_port_attach(const char * port, char * response, size_t size)
+    OVS_REQUIRES(dpdk_mutex)
+{
+    int ret;
+    uint8_t port_id;
+
+    ret = rte_eth_dev_attach(port, &port_id);
+    if (ret < 0) {
+        snprintf(response, size, "Error attaching device '%s'", port);
+        return -1;
+    }
+
+    snprintf(response, size,
+             "Device '%s' has been attached as 'dpdk%d'", port, port_id);
+    return 0;
+}
+
+static int
+dpdk_port_detach(const char * port, char * response, size_t size)
+    OVS_REQUIRES(dpdk_mutex)
+{
+    int ret;
+    unsigned int parsed_port;
+    uint8_t port_id;
+    char devname[RTE_ETH_NAME_MAX_LEN];
+
+    ret = dpdk_dev_parse_name(port, "dpdk", &parsed_port);
+    if (ret) {
+        snprintf(response, size, "'%s' is not a valid dpdk device", port);
+        return -1;
+    }
+
+    port_id = parsed_port;
+
+    struct netdev *netdev = netdev_from_name(port);
+    if (netdev) {
+        netdev_close(netdev);
+        snprintf(response, size,
+                 "Port '%s' is being used. Remove it before detaching", port);
+        return -1;
+    }
+
+    rte_eth_dev_close(port_id);
+
+    ret = rte_eth_dev_detach(port_id, devname);
+    if (ret < 0) {
+        snprintf(response, size, "Port '%s' can not be detached", port);
+        return -1;
+    }
+
+    snprintf(response, size, "Port '%s' has been detached", port);
+    return 0;
+}
+
+static void
+netdev_dpdk_port_ctl(struct unixctl_conn *conn, int argc OVS_UNUSED,
+                     const char *argv[], void *aux OVS_UNUSED)
+{
+    int ret;
+    char response[512];
+
+    ovs_mutex_lock(&dpdk_mutex);
+
+    if (strcmp(argv[1], "attach") == 0) {
+        ret = dpdk_port_attach(argv[2], response, sizeof(response));
+    } else if (strcmp(argv[1], "detach") == 0) {
+        ret = dpdk_port_detach(argv[2], response, sizeof(response));
+    } else {
+        snprintf(response, sizeof(response),
+                 "'%s' is not a valid argument", argv[1]);
+        ret = -1;
+    }
+
+    ovs_mutex_unlock(&dpdk_mutex);
+
+    if (ret) {
+        unixctl_command_reply_error(conn, response);
+    } else {
+        unixctl_command_reply(conn, response);
+    }
+}
+
 /*
  * Set virtqueue flags so that we do not receive interrupts.
  */
@@ -2282,6 +2365,10 @@  dpdk_common_init(void)
                              "[netdev] up|down", 1, 2,
                              netdev_dpdk_set_admin_state, NULL);
 
+    unixctl_command_register("netdev-dpdk/port-ctl",
+                             "attach/detach device", 2, 2,
+                             netdev_dpdk_port_ctl, NULL);
+
     ovs_thread_create("dpdk_watchdog", dpdk_watchdog, NULL);
 }
 
@@ -2293,7 +2380,7 @@  dpdk_ring_create(const char dev_name[], unsigned int port_no,
 {
     struct dpdk_ring *ivshmem;
     char ring_name[RTE_RING_NAMESIZE];
-    int err;
+    int err, port_id;
 
     ivshmem = dpdk_rte_mzalloc(sizeof *ivshmem);
     if (ivshmem == NULL) {
@@ -2327,19 +2414,20 @@  dpdk_ring_create(const char dev_name[], unsigned int port_no,
         return ENOMEM;
     }
 
-    err = rte_eth_from_rings(dev_name, &ivshmem->cring_rx, 1,
-                             &ivshmem->cring_tx, 1, SOCKET0);
+    port_id = rte_eth_from_rings(dev_name, &ivshmem->cring_rx, 1,
+                                 &ivshmem->cring_tx, 1, SOCKET0);
 
-    if (err < 0) {
+    if (port_id < 0) {
         rte_free(ivshmem);
         return ENODEV;
     }
 
     ivshmem->user_port_id = port_no;
-    ivshmem->eth_port_id = rte_eth_dev_count() - 1;
+    ivshmem->eth_port_id = port_id;
+    *eth_port_id = port_id;
+
     ovs_list_push_back(&dpdk_ring_list, &ivshmem->list_node);
 
-    *eth_port_id = ivshmem->eth_port_id;
     return 0;
 }