[ovs-dev] [PATCH RFC] netdev-dpdk: Allow specification of index for PCI devices

[Ciara Loftus]

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. Whereas before only one of N ports associated with one PCI
address could be added, now N can.

This patch allows for the following use of the dpdk-devargs option:

ovs-vsctl set Interface myport options:dpdk-devargs=0000:06:00.0,X

Where X is an unsigned integer representing one of multiple ports
associated with the PCI address provided.

This patch has not been tested.

Signed-off-by: Ciara Loftus <ciara.loftus at intel.com>
---
 lib/netdev-dpdk.c | 79 ++++++++++++++++++++++++++++++++++++++++++++-----------
 1 file changed, 63 insertions(+), 16 deletions(-)

diff --git a/lib/netdev-dpdk.c b/lib/netdev-dpdk.c
index c60f46f..c3562a3 100644
--- a/lib/netdev-dpdk.c
+++ b/lib/netdev-dpdk.c
@@ -1214,30 +1214,77 @@ netdev_dpdk_lookup_by_port_id(dpdk_port_t port_id)
 }
 
 static dpdk_port_t
+process_devargs_index(char *name, int idx)
+{
+    int i = 0;
+    struct rte_eth_dev_info dev_info;
+    char pci_addr[PCI_PRI_STR_SIZE];
+    dpdk_port_t offset_port_id = DPDK_ETH_PORT_ID_INVALID;
+
+    for (i = 0; i < RTE_MAX_ETHPORTS; i++) {
+        if (!rte_eth_dev_is_valid_port(i)) {
+            continue;
+        }
+        rte_eth_dev_info_get(i, &dev_info);
+        rte_pci_device_name(&dev_info.pci_dev->addr, pci_addr,
+                            sizeof(pci_addr));
+        if (!strcmp(pci_addr, name)) {
+            offset_port_id = i + idx;
+            if (rte_eth_dev_is_valid_port(offset_port_id)) {
+                rte_eth_dev_info_get(offset_port_id, &dev_info);
+                rte_pci_device_name(&dev_info.pci_dev->addr, pci_addr,
+                                    sizeof(pci_addr));
+                if (!strcmp(pci_addr, name)) {
+                    return offset_port_id;
+                } else {
+                    break;
+                }
+            } else {
+                break;
+            }
+        }
+    }
+
+    VLOG_INFO("Invalid PCI offset %i for device %s", idx, name);
+    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 *devargs_copy = xmemdup0((devargs), strlen(devargs));
+    char *name, *idx_str;
+    unsigned idx;
     dpdk_port_t new_port_id = DPDK_ETH_PORT_ID_INVALID;
 
-    if (!rte_eth_dev_count()
-            || 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);
+    name = strtok_r(devargs_copy, ",", &devargs_copy);
+    idx_str = strtok_r(devargs_copy, ",", &devargs_copy);
+
+    if (idx_str) {
+        idx = atoi(idx_str);
+        new_port_id = process_devargs_index(name, idx);
+    } else {
+        if (!rte_eth_dev_count()
+                || 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);
+    }
+
     return new_port_id;
 }
 
-- 
2.7.5