netdev-dpdk: NUMA Aware vHost User

This commit allows for vHost User memory from QEMU, DPDK and OVS, as
well as the servicing PMD, to all come from the same socket.

The socket id of a vhost-user port used to be set to that of the master
lcore. Now it is possible to update the socket id if it is detected
(during VM boot) that the vhost device memory is not on this node. If
this is the case, a new mempool is created from the new node, and the
PMD thread currently servicing the port will no longer, in favour of a
thread from the new node (if enabled in the pmd-cpu-mask).

To avail of this functionality, one must enable the
CONFIG_RTE_LIBRTE_VHOST_NUMA DPDK configuration option.

Signed-off-by: Ciara Loftus <ciara.loftus@intel.com>
Acked-by: Daniele Di Proietto <diproiettod@vmware.com>

1 files changed, 34 insertions, 3 deletions

diff --git a/lib/netdev-dpdk.c b/lib/netdev-dpdk.c
index 582569c50..fc0c8d351 100644
--- a/lib/netdev-dpdk.c
+++ b/lib/netdev-dpdk.c
@@ -30,6 +30,7 @@
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <getopt.h>
+#include <numaif.h>
 
 #include "dirs.h"
 #include "dp-packet.h"
@@ -382,6 +383,9 @@ struct netdev_dpdk {
     int requested_n_txq;
     int requested_n_rxq;
 
+    /* Socket ID detected when vHost device is brought up */
+    int requested_socket_id;
+
     /* Ingress Policer */
     OVSRCU_TYPE(struct ingress_policer *) ingress_policer;
     uint32_t policer_rate;
@@ -758,6 +762,7 @@ netdev_dpdk_init(struct netdev *netdev, unsigned int port_no,
     }
 
     dev->socket_id = sid < 0 ? SOCKET0 : sid;
+    dev->requested_socket_id = dev->socket_id;
     dev->port_id = port_no;
     dev->type = type;
     dev->flags = 0;
@@ -2322,6 +2327,8 @@ new_device(struct virtio_net *virtio_dev)
 {
     struct netdev_dpdk *dev;
     bool exists = false;
+    int newnode = 0;
+    long err = 0;
 
     ovs_mutex_lock(&dpdk_mutex);
     /* Add device to the vhost port with the same name as that passed down. */
@@ -2335,6 +2342,19 @@ new_device(struct virtio_net *virtio_dev)
             }
             ovsrcu_set(&dev->virtio_dev, virtio_dev);
             exists = true;
+
+            /* Get NUMA information */
+            err = get_mempolicy(&newnode, NULL, 0, virtio_dev,
+                                MPOL_F_NODE | MPOL_F_ADDR);
+            if (err) {
+                VLOG_INFO("Error getting NUMA info for vHost Device '%s'",
+                        virtio_dev->ifname);
+                newnode = dev->socket_id;
+            } else if (newnode != dev->socket_id) {
+                dev->requested_socket_id = newnode;
+                netdev_request_reconfigure(&dev->up);
+            }
+
             virtio_dev->flags |= VIRTIO_DEV_RUNNING;
             /* Disable notifications. */
             set_irq_status(virtio_dev);
@@ -2352,8 +2372,8 @@ new_device(struct virtio_net *virtio_dev)
         return -1;
     }
 
-    VLOG_INFO("vHost Device '%s' %"PRIu64" has been added", virtio_dev->ifname,
-              virtio_dev->device_fh);
+    VLOG_INFO("vHost Device '%s' %"PRIu64" has been added on numa node %i",
+              virtio_dev->ifname, virtio_dev->device_fh, newnode);
     return 0;
 }
 
@@ -2915,6 +2935,7 @@ static int
 netdev_dpdk_vhost_user_reconfigure(struct netdev *netdev)
 {
     struct netdev_dpdk *dev = netdev_dpdk_cast(netdev);
+    int err = 0;
 
     ovs_mutex_lock(&dpdk_mutex);
     ovs_mutex_lock(&dev->mutex);
@@ -2922,10 +2943,20 @@ netdev_dpdk_vhost_user_reconfigure(struct netdev *netdev)
     netdev->n_txq = dev->requested_n_txq;
     netdev->n_rxq = dev->requested_n_rxq;
 
+    if (dev->requested_socket_id != dev->socket_id) {
+        dev->socket_id = dev->requested_socket_id;
+        /* Change mempool to new NUMA Node */
+        dpdk_mp_put(dev->dpdk_mp);
+        dev->dpdk_mp = dpdk_mp_get(dev->socket_id, dev->mtu);
+        if (!dev->dpdk_mp) {
+            err = ENOMEM;
+        }
+    }
+
     ovs_mutex_unlock(&dev->mutex);
     ovs_mutex_unlock(&dpdk_mutex);
 
-    return 0;
+    return err;
 }
 
 static int