[ovs-dev] [PATCH] netdev-dpdk: fix port addition for ports sharing same PCI id

[Yuanhan Liu]

Some NICs have only one PCI address associated with multiple ports. This
patch extends the dpdk-devargs option's format to cater for such devices.

To achieve that, this patch uses a new syntax that will be adapted and
implemented in future DPDK release (likely, v18.05):
    http://dpdk.org/ml/archives/dev/2017-December/084234.html

And since it's the DPDK duty to parse the (complete and full) syntax
and this patch is more likely to serve as an intermediate workaround,
here I take a simpler and shorter syntax from it (note it's allowed to
have only one category being provided):
    class=eth,mac=00:11:22:33:44:55:66

Also, old compatibility is kept. Users can still go on with using the
PCI id to add a port (if that's enough for them). Meaning, this patch
will not break anything.

This patch is basically based on the one from Ciara:
    https://mail.openvswitch.org/pipermail/ovs-dev/2017-October/339496.html

Cc: Loftus Ciara <ciara.loftus at intel.com>
Cc: Thomas Monjalon <thomas at monjalon.net>
Cc: Kevin Traynor <ktraynor at redhat.com>
Signed-off-by: Yuanhan Liu <yliu at fridaylinux.org>
---
 lib/netdev-dpdk.c | 77 ++++++++++++++++++++++++++++++++++++++++++++-----------
 1 file changed, 62 insertions(+), 15 deletions(-)

diff --git a/lib/netdev-dpdk.c b/lib/netdev-dpdk.c
index 45fcc74..4e5cc25 100644
--- a/lib/netdev-dpdk.c
+++ b/lib/netdev-dpdk.c
@@ -1205,30 +1205,77 @@ netdev_dpdk_lookup_by_port_id(dpdk_port_t port_id)
     return NULL;
 }
 
+static int
+netdev_dpdk_str_to_ether(const char *mac, struct ether_addr *ea)
+{
+    unsigned int bytes[6];
+    int i;
+
+    if (sscanf(mac, "%x:%x:%x:%x:%x:%x",
+               &bytes[0], &bytes[1], &bytes[2],
+               &bytes[3], &bytes[4], &bytes[5]) != 6) {
+        return -1;
+    }
+
+    for (i = 0; i < 6; i++) {
+        ea->addr_bytes[i] = bytes[i];
+    }
+
+    return 0;
+}
+
+static dpdk_port_t
+netdev_dpdk_get_port_by_mac(const char *mac_str)
+{
+    int i;
+    struct ether_addr mac;
+    struct ether_addr port_mac;
+
+    netdev_dpdk_str_to_ether(mac_str, &mac);
+    for (i = 0; i < RTE_MAX_ETHPORTS; i++) {
+        if (!rte_eth_dev_is_valid_port(i)) {
+            continue;
+        }
+
+        rte_eth_macaddr_get(i, &port_mac);
+        if (is_same_ether_addr(&mac, &port_mac)) {
+            return i;
+        }
+    }
+
+    return DPDK_ETH_PORT_ID_INVALID;
+}
+
 static dpdk_port_t
 netdev_dpdk_process_devargs(struct netdev_dpdk *dev,
                             const char *devargs, char **errp)
 {
-    /* Get the name up to the first comma. */
-    char *name = xmemdup0(devargs, strcspn(devargs, ","));
+    char *name;
     dpdk_port_t new_port_id = DPDK_ETH_PORT_ID_INVALID;
 
-    if (rte_eth_dev_get_port_by_name(name, &new_port_id)
-            || !rte_eth_dev_is_valid_port(new_port_id)) {
-        /* Device not found in DPDK, attempt to attach it */
-        if (!rte_eth_dev_attach(devargs, &new_port_id)) {
-            /* Attach successful */
-            dev->attached = true;
-            VLOG_INFO("Device '%s' attached to DPDK", devargs);
-        } else {
-            /* Attach unsuccessful */
-            new_port_id = DPDK_ETH_PORT_ID_INVALID;
-            VLOG_WARN_BUF(errp, "Error attaching device '%s' to DPDK",
-                          devargs);
+    if (strncmp(devargs, "class=eth,mac=", 14) == 0) {
+        new_port_id = netdev_dpdk_get_port_by_mac(&devargs[14]);
+    } else {
+        name = xmemdup0(devargs, strcspn(devargs, ","));
+        if (rte_eth_dev_get_port_by_name(name, &new_port_id)
+                || !rte_eth_dev_is_valid_port(new_port_id)) {
+            /* Device not found in DPDK, attempt to attach it */
+            if (!rte_eth_dev_attach(devargs, &new_port_id)) {
+                /* Attach successful */
+                dev->attached = true;
+                VLOG_INFO("Device '%s' attached to DPDK", devargs);
+            } else {
+                /* Attach unsuccessful */
+                new_port_id = DPDK_ETH_PORT_ID_INVALID;
+            }
         }
+        free(name);
+    }
+
+    if (new_port_id == DPDK_ETH_PORT_ID_INVALID) {
+        VLOG_WARN_BUF(errp, "Error attaching device '%s' to DPDK", devargs);
     }
 
-    free(name);
     return new_port_id;
 }
 
-- 
2.7.4