[ovs-dev] [PATCH] netdev-dpdk: add sflow support for vhost-user ports

Kavanagh, Mark B mark.b.kavanagh at intel.com
Wed May 4 14:42:52 UTC 2016


Hi Przemek,

Apologies for the churn, but some additional points occurred to me - please refer to comments in netdev_dpdk_get_ifindex.

Thanks,
Mark

>
>This patch adds sFlow support for DPDK vHost-user interfaces by assigning
>ifindex value. Values of ifindexes for vHost-user interfaces start with 2000
>to avoid overlapping with kernel datapath interfaces.
>
>Patch also fixes issue with 'dpdk0' interface being ignored by sFlow agent,
>because of ifindex 0. Ifindexes values for physical DPDK interfaces start
>with 1000 to avoid overlapping with kernel datapath interfaces.
>
>Signed-off-by: Przemyslaw Lal <przemyslawx.lal at intel.com>
>---
> lib/netdev-dpdk.c | 67 ++++++++++++++++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 66 insertions(+), 1 deletion(-)
>
>diff --git a/lib/netdev-dpdk.c b/lib/netdev-dpdk.c
>index 208c5f5..568bce6 100644
>--- a/lib/netdev-dpdk.c
>+++ b/lib/netdev-dpdk.c
>@@ -115,6 +115,18 @@ static char *vhost_sock_dir = NULL;   /* Location of vhost-user sockets
>*/
>  */
> #define VHOST_ENQ_RETRY_USECS 100
>
>+/* For DPDK ETH interfaces use ifindex values starting with 1000
>+ * to avoid overlapping with kernel-space interfaces.
>+ * Also starting with 0 would cause sFlow to ignore 'dpdk0' interface.
>+ */
>+#define DPDK_PORT_ID_TO_IFINDEX(port_id) ((port_id) + 1000)
>+
>+/* For DPDK vhost-user interfaces use ifindexes starting with 2000.
>+ */
>+#define VHOST_ID_TO_IFINDEX(port_id) ((port_id) + 2000)
>+
>+#define VHOST_IDS_MAX_LEN 1024
>+
> static const struct rte_eth_conf port_conf = {
>     .rxmode = {
>         .mq_mode = ETH_MQ_RX_RSS,
>@@ -149,6 +161,7 @@ enum dpdk_dev_type {
> static int rte_eal_init_ret = ENODEV;
>
> static struct ovs_mutex dpdk_mutex = OVS_MUTEX_INITIALIZER;
>+static struct ovs_mutex vhost_mutex = OVS_MUTEX_INITIALIZER;
>
> /* Quality of Service */
>
>@@ -790,6 +803,51 @@ netdev_dpdk_vhost_cuse_construct(struct netdev *netdev)
>     return err;
> }
>
>+/* Counter for VHOST interfaces as DPDK library doesn't provide mechanism
>+ * similar to rte_eth_dev_count for vhost-user sockets.
>+ */
>+static int vhost_counter OVS_GUARDED_BY(vhost_mutex) = 0;
>+
>+/* Array storing vhost_ids, so their ifindex can be reused after socket
>+ * recreation.
>+ */
>+static char vhost_ids[VHOST_IDS_MAX_LEN][PATH_MAX] OVS_GUARDED_BY(vhost_mutex);
>+
>+/* Simple lookup in vhost_ids array.
>+ * On success returns id of vhost_id stored in the array,
>+ * otherwise returns -1.
>+ */
>+static int
>+netdev_dpdk_lookup_vhost_id(struct netdev_dpdk *dev) OVS_REQUIRES(vhost_mutex)
>+{
>+    for (int i = 0; i < vhost_counter; i++) {
>+        if (strncmp(vhost_ids[i], dev->vhost_id, strlen(dev->vhost_id)) == 0) {
>+            return i;
>+        }
>+    }
>+    return -1;
>+}
>+
>+/* Inserts vhost_id at the first free position in the vhost_ids array.
>+ */
>+static void
>+netdev_dpdk_push_vhost_id(struct netdev_dpdk *dev)
>+{
>+    ovs_mutex_lock(&vhost_mutex);
>+    if (netdev_dpdk_lookup_vhost_id(dev) < 0) {
>+        if (vhost_counter < VHOST_IDS_MAX_LEN) {
>+            strncpy(vhost_ids[vhost_counter++], dev->vhost_id,
>+                    strlen(dev->vhost_id));
>+        }
>+        else {
>+            VLOG_WARN("Could not assign ifindex to \"%s\" port. "
>+                      "List of vhost IDs list is full.",
>+                      dev->vhost_id);
>+        }
>+    }
>+    ovs_mutex_unlock(&vhost_mutex);
>+}
>+
> static int
> netdev_dpdk_vhost_user_construct(struct netdev *netdev)
> {
>@@ -825,6 +883,8 @@ netdev_dpdk_vhost_user_construct(struct netdev *netdev)
>         err = vhost_construct_helper(netdev);
>     }
>
>+    netdev_dpdk_push_vhost_id(dev);
>+
>     ovs_mutex_unlock(&dpdk_mutex);
>     return err;
> }
>@@ -1775,7 +1835,12 @@ netdev_dpdk_get_ifindex(const struct netdev *netdev)
>     int ifindex;
>
>     ovs_mutex_lock(&dev->mutex);
>-    ifindex = dev->port_id;
>+    if (dev->type == DPDK_DEV_ETH) {
>+        ifindex = DPDK_PORT_ID_TO_IFINDEX(dev->port_id);
>+    }

<micro-nit> use BSD-style braces for the 'else' case </micro-nit>

>+    else {

This case applies to both vHost User and vHost Cuse ports - is there an issue in the latter case?

>+        ifindex = VHOST_ID_TO_IFINDEX(netdev_dpdk_lookup_vhost_id(dev));

Potential bug here if netdev_dpdk_lookup_vhost_id returns -1.


>+    }
>     ovs_mutex_unlock(&dev->mutex);
>
>     return ifindex;
>--
>2.1.0




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