net/vdev_netvsc: prefer netvsc devices in scan

There is an option to run a non-netvsc device as a netvsc device only
when the "force" parameter is set to 1 in the EAL command line.
Consequently, more than one device may be found to be matching the
"mac" parameter specifying the device.

Prefer netvsc devices to be scanned before any non-netvsc device, even
when the "force" parameter is set.

Cc: stable@dpdk.org
Signed-off-by: Matan Azrad <matan@mellanox.com>

diff --git a/drivers/net/vdev_netvsc/vdev_netvsc.c b/drivers/net/vdev_netvsc/vdev_netvsc.c
index 79d1324..c321a9f 100644 (file)
--- a/drivers/net/vdev_netvsc/vdev_netvsc.c
+++ b/drivers/net/vdev_netvsc/vdev_netvsc.c
@@ -97,6 +97,43 @@ vdev_netvsc_ctx_destroy(struct vdev_netvsc_ctx *ctx)
        free(ctx);
 }
 
+/**
+ * Determine if a network interface is NetVSC.
+ *
+ * @param[in] iface
+ *   Pointer to netdevice description structure (name and index).
+ *
+ * @return
+ *   A nonzero value when interface is detected as NetVSC. In case of error,
+ *   rte_errno is updated and 0 returned.
+ */
+static int
+vdev_netvsc_iface_is_netvsc(const struct if_nameindex *iface)
+{
+       static const char temp[] = "/sys/class/net/%s/device/class_id";
+       char path[sizeof(temp) + IF_NAMESIZE];
+       FILE *f;
+       int ret;
+       int len = 0;
+
+       ret = snprintf(path, sizeof(path), temp, iface->if_name);
+       if (ret == -1 || (size_t)ret >= sizeof(path)) {
+               rte_errno = ENOBUFS;
+               return 0;
+       }
+       f = fopen(path, "r");
+       if (!f) {
+               rte_errno = errno;
+               return 0;
+       }
+       ret = fscanf(f, NETVSC_CLASS_ID "%n", &len);
+       if (ret == EOF)
+               rte_errno = errno;
+       ret = len == (int)strlen(NETVSC_CLASS_ID);
+       fclose(f);
+       return ret;
+}
+
 /**
  * Iterate over system network interfaces.
  *
@@ -106,6 +143,8 @@ vdev_netvsc_ctx_destroy(struct vdev_netvsc_ctx *ctx)
  * @param func
  *   Callback function pointer. List traversal is aborted when this function
  *   returns a nonzero value.
+ * @param is_netvsc
+ *   Indicates the device type to iterate - netvsc or non-netvsc.
  * @param ...
  *   Variable parameter list passed as @p va_list to @p func.
  *
@@ -117,7 +156,7 @@ vdev_netvsc_ctx_destroy(struct vdev_netvsc_ctx *ctx)
 static int
 vdev_netvsc_foreach_iface(int (*func)(const struct if_nameindex *iface,
                                      const struct ether_addr *eth_addr,
-                                     va_list ap), ...)
+                                     va_list ap), int is_netvsc, ...)
 {
        struct if_nameindex *iface = if_nameindex();
        int s = socket(PF_INET, SOCK_DGRAM, IPPROTO_IP);
@@ -135,10 +174,14 @@ vdev_netvsc_foreach_iface(int (*func)(const struct if_nameindex *iface,
                goto error;
        }
        for (i = 0; iface[i].if_name; ++i) {
+               int is_netvsc_ret;
                struct ifreq req;
                struct ether_addr eth_addr;
                va_list ap;
 
+               is_netvsc_ret = vdev_netvsc_iface_is_netvsc(&iface[i]) ? 1 : 0;
+               if (is_netvsc ^ is_netvsc_ret)
+                       continue;
                strncpy(req.ifr_name, iface[i].if_name, sizeof(req.ifr_name));
                if (ioctl(s, SIOCGIFHWADDR, &req) == -1) {
                        DRV_LOG(WARNING, "cannot retrieve information about"
@@ -153,7 +196,7 @@ vdev_netvsc_foreach_iface(int (*func)(const struct if_nameindex *iface,
                }
                memcpy(eth_addr.addr_bytes, req.ifr_hwaddr.sa_data,
                       RTE_DIM(eth_addr.addr_bytes));
-               va_start(ap, func);
+               va_start(ap, is_netvsc);
                ret = func(&iface[i], &eth_addr, ap);
                va_end(ap);
                if (ret)
@@ -167,43 +210,6 @@ error:
        return ret;
 }
 
-/**
- * Determine if a network interface is NetVSC.
- *
- * @param[in] iface
- *   Pointer to netdevice description structure (name and index).
- *
- * @return
- *   A nonzero value when interface is detected as NetVSC. In case of error,
- *   rte_errno is updated and 0 returned.
- */
-static int
-vdev_netvsc_iface_is_netvsc(const struct if_nameindex *iface)
-{
-       static const char temp[] = "/sys/class/net/%s/device/class_id";
-       char path[sizeof(temp) + IF_NAMESIZE];
-       FILE *f;
-       int ret;
-       int len = 0;
-
-       ret = snprintf(path, sizeof(path), temp, iface->if_name);
-       if (ret == -1 || (size_t)ret >= sizeof(path)) {
-               rte_errno = ENOBUFS;
-               return 0;
-       }
-       f = fopen(path, "r");
-       if (!f) {
-               rte_errno = errno;
-               return 0;
-       }
-       ret = fscanf(f, NETVSC_CLASS_ID "%n", &len);
-       if (ret == EOF)
-               rte_errno = errno;
-       ret = len == (int)strlen(NETVSC_CLASS_ID);
-       fclose(f);
-       return ret;
-}
-
 /**
  * Determine if a network interface has a route.
  *
@@ -379,8 +385,6 @@ vdev_netvsc_device_probe(const struct if_nameindex *iface,
                strncpy(ctx->if_name, iface->if_name, sizeof(ctx->if_name));
                return 0;
        }
-       if (vdev_netvsc_iface_is_netvsc(iface))
-               return 0;
        if (!is_same_ether_addr(eth_addr, &ctx->if_addr))
                return 0;
        /* Look for associated PCI device. */
@@ -449,7 +453,8 @@ vdev_netvsc_alarm(__rte_unused void *arg)
        int ret;
 
        LIST_FOREACH(ctx, &vdev_netvsc_ctx_list, entry) {
-               ret = vdev_netvsc_foreach_iface(vdev_netvsc_device_probe, ctx);
+               ret = vdev_netvsc_foreach_iface(vdev_netvsc_device_probe, 0,
+                     ctx);
                if (ret < 0)
                        break;
        }
@@ -505,7 +510,6 @@ vdev_netvsc_netvsc_probe(const struct if_nameindex *iface,
 {
        const char *name = va_arg(ap, const char *);
        struct rte_kvargs *kvargs = va_arg(ap, struct rte_kvargs *);
-       int force = va_arg(ap, int);
        unsigned int specified = va_arg(ap, unsigned int);
        unsigned int *matched = va_arg(ap, unsigned int *);
        unsigned int i;
@@ -559,13 +563,6 @@ vdev_netvsc_netvsc_probe(const struct if_nameindex *iface,
                        iface->if_name, iface->if_index);
                return 0;
        }
-       if (!vdev_netvsc_iface_is_netvsc(iface)) {
-               if (!specified || !force)
-                       return 0;
-               DRV_LOG(WARNING,
-                       "using non-NetVSC interface \"%s\" (index %u)",
-                       iface->if_name, iface->if_index);
-       }
        /* Routed NetVSC should not be probed. */
        if (vdev_netvsc_has_route(iface, AF_INET) ||
            vdev_netvsc_has_route(iface, AF_INET6)) {
@@ -632,7 +629,7 @@ vdev_netvsc_netvsc_probe(const struct if_nameindex *iface,
        /* Request virtual device generation. */
        DRV_LOG(DEBUG, "generating virtual device \"%s\" with arguments \"%s\"",
                ctx->devname, ctx->devargs);
-       vdev_netvsc_foreach_iface(vdev_netvsc_device_probe, ctx);
+       vdev_netvsc_foreach_iface(vdev_netvsc_device_probe, 0, ctx);
        ret = rte_eal_hotplug_add("vdev", ctx->devname, ctx->devargs);
        if (ret)
                goto error;
@@ -709,14 +706,25 @@ vdev_netvsc_vdev_probe(struct rte_vdev_device *dev)
        }
        rte_eal_alarm_cancel(vdev_netvsc_alarm, NULL);
        /* Gather interfaces. */
-       ret = vdev_netvsc_foreach_iface(vdev_netvsc_netvsc_probe, name, kvargs,
-                                       force, specified, &matched);
+       ret = vdev_netvsc_foreach_iface(vdev_netvsc_netvsc_probe, 1, name,
+                                       kvargs, specified, &matched);
        if (ret < 0)
                goto error;
-       if (matched < specified)
-               DRV_LOG(WARNING,
-                       "some of the specified parameters did not match"
-                       " recognized network interfaces");
+       if (specified && matched < specified) {
+               if (!force) {
+                       DRV_LOG(ERR, "Cannot find the specified netvsc device");
+                       goto error;
+               }
+               /* Try to force probing on non-netvsc specified device. */
+               if (vdev_netvsc_foreach_iface(vdev_netvsc_netvsc_probe, 0, name,
+                                             kvargs, specified, &matched) < 0)
+                       goto error;
+               if (matched < specified) {
+                       DRV_LOG(ERR, "Cannot find the specified device");
+                       goto error;
+               }
+               DRV_LOG(WARNING, "non-netvsc device was probed as netvsc");
+       }
        ret = rte_eal_alarm_set(VDEV_NETVSC_PROBE_MS * 1000,
                                vdev_netvsc_alarm, NULL);
        if (ret < 0) {