[ovs-dev] [PATCH RFC v4 1/3] netdev-dpdk: add hotplug support

Ciara Loftus ciara.loftus at intel.com
Fri Oct 28 14:45:56 UTC 2016


In order to use dpdk ports in ovs they have to be bound to a DPDK
compatible driver before ovs is started.

This patch adds the possibility to hotplug (or hot-unplug) a device
after ovs has been started. The implementation adds two appctl commands:
netdev-dpdk/port-attach and netdev-dpdk/port-detach

After the user attaches a new device, it has to be added to a bridge
using the add-port command, similarly, before detaching a device,
it has to be removed using the del-port command.

Signed-off-by: Mauricio Vasquez B <mauricio.vasquezbernal at studenti.polito.it>
---
 INSTALL.DPDK-ADVANCED.md | 25 +++++++++++++
 NEWS                     |  1 +
 lib/netdev-dpdk.c        | 96 +++++++++++++++++++++++++++++++++++++++++++++---
 3 files changed, 116 insertions(+), 6 deletions(-)

diff --git a/INSTALL.DPDK-ADVANCED.md b/INSTALL.DPDK-ADVANCED.md
index 0d6bcfa..7d90219 100644
--- a/INSTALL.DPDK-ADVANCED.md
+++ b/INSTALL.DPDK-ADVANCED.md
@@ -15,6 +15,7 @@ OVS DPDK ADVANCED INSTALL GUIDE
 10. [Pdump](#pdump)
 11. [Jumbo Frames](#jumbo)
 12. [Vsperf](#vsperf)
+13. [Port Hotplug](#hotplug)
 
 ## <a name="overview"></a> 1. Overview
 
@@ -880,6 +881,29 @@ environment. More information can be found in below link.
 
 https://wiki.opnfv.org/display/vsperf/VSperf+Home
 
+## <a name="hotplug"></a> 13. 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-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-detach dpdk0`
+
+This feature is not supported with VFIO and could not work with some NICs,
+please refer to the [DPDK Port Hotplug Framework] in order to get more
+information.
 
 Bug Reporting:
 --------------
@@ -896,3 +920,4 @@ Please report problems to bugs at openvswitch.org.
 [Vhost walkthrough]: INSTALL.DPDK.rst#vhost
 [INSTALL DPDK]: INSTALL.DPDK.rst#build
 [INSTALL OVS]: INSTALL.DPDK.rst#build
+[DPDK Port Hotplug Framework]: http://dpdk.org/doc/guides/prog_guide/port_hotplug_framework.html#hotplug
diff --git a/NEWS b/NEWS
index d07ec45..c335547 100644
--- a/NEWS
+++ b/NEWS
@@ -33,6 +33,7 @@ Post-v2.6.0
    - DPDK:
      * New option 'n_rxq_desc' and 'n_txq_desc' fields for DPDK interfaces
        which set the number of rx and tx descriptors to use for the given port.
+     * Port Hotplug is now supported.
    - Fedora packaging:
      * A package upgrade does not automatically restart OVS service.
 
diff --git a/lib/netdev-dpdk.c b/lib/netdev-dpdk.c
index 7c1523e..c102506 100644
--- a/lib/netdev-dpdk.c
+++ b/lib/netdev-dpdk.c
@@ -2291,6 +2291,83 @@ netdev_dpdk_set_admin_state(struct unixctl_conn *conn, int argc,
     unixctl_command_reply(conn, "OK");
 }
 
+static void
+netdev_dpdk_port_attach(struct unixctl_conn *conn, int argc OVS_UNUSED,
+                        const char *argv[], void *aux OVS_UNUSED)
+{
+    int ret;
+    char response[128];
+    uint8_t port_id;
+
+    ovs_mutex_lock(&dpdk_mutex);
+
+    ret = rte_eth_dev_attach(argv[1], &port_id);
+    if (ret < 0) {
+        snprintf(response, sizeof(response),
+                 "Error attaching device '%s'", argv[1]);
+        ovs_mutex_unlock(&dpdk_mutex);
+        unixctl_command_reply_error(conn, response);
+        return;
+    }
+
+    snprintf(response, sizeof(response),
+             "Device '%s' has been attached as 'dpdk%d'", argv[1], port_id);
+
+    ovs_mutex_unlock(&dpdk_mutex);
+    unixctl_command_reply(conn, response);
+}
+
+static void
+netdev_dpdk_port_detach(struct unixctl_conn *conn, int argc OVS_UNUSED,
+                        const char *argv[], void *aux OVS_UNUSED)
+{
+    int ret;
+    char response[128];
+    unsigned int parsed_port;
+    uint8_t port_id;
+    char devname[RTE_ETH_NAME_MAX_LEN];
+
+    ovs_mutex_lock(&dpdk_mutex);
+
+    ret = dpdk_dev_parse_name(argv[1], "dpdk", &parsed_port);
+    if (ret) {
+        snprintf(response, sizeof(response),
+                 "'%s' is not a valid port", argv[1]);
+        goto error;
+    }
+
+    port_id = parsed_port;
+
+    struct netdev *netdev = netdev_from_name(argv[1]);
+    if (netdev) {
+        netdev_close(netdev);
+        snprintf(response, sizeof(response),
+                 "Port '%s' is being used. Remove it before detaching",
+                 argv[1]);
+        goto error;
+    }
+
+    rte_eth_dev_close(port_id);
+
+    ret = rte_eth_dev_detach(port_id, devname);
+    if (ret < 0) {
+        snprintf(response, sizeof(response),
+                 "Port '%s' can not be detached", argv[1]);
+        goto error;
+    }
+
+    snprintf(response, sizeof(response),
+             "Port '%s' has been detached", argv[1]);
+
+    ovs_mutex_unlock(&dpdk_mutex);
+    unixctl_command_reply(conn, response);
+    return;
+
+error:
+    ovs_mutex_unlock(&dpdk_mutex);
+    unixctl_command_reply_error(conn, response);
+}
+
 /*
  * Set virtqueue flags so that we do not receive interrupts.
  */
@@ -2566,6 +2643,12 @@ netdev_dpdk_class_init(void)
         unixctl_command_register("netdev-dpdk/set-admin-state",
                                  "[netdev] up|down", 1, 2,
                                  netdev_dpdk_set_admin_state, NULL);
+        unixctl_command_register("netdev-dpdk/port-attach",
+                                 "pci address of device", 1, 1,
+                                 netdev_dpdk_port_attach, NULL);
+        unixctl_command_register("netdev-dpdk/port-detach",
+                                 "port", 1, 1,
+                                 netdev_dpdk_port_detach, NULL);
 
         ovsthread_once_done(&once);
     }
@@ -2601,7 +2684,7 @@ dpdk_ring_create(const char dev_name[], unsigned int port_no,
 {
     struct dpdk_ring *ivshmem;
     char *ring_name;
-    int err;
+    int port_id;
 
     ivshmem = dpdk_rte_mzalloc(sizeof *ivshmem);
     if (!ivshmem) {
@@ -2631,19 +2714,20 @@ 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;
 }
 
-- 
2.4.3




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