Description: To support kernels or dkms builds of mlx5_core driver with
 https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git/commit/?id=123f0f53dd64b67e34142485fe866a8a581f12f1
Origin: backport, https://github.com/libvirt/libvirt/commit/5b1c525b1f3608156884aed0dc5e925306c1e260
Bug-Ubuntu: https://bugs.launchpad.net/bugs/1892132
Last-Update: 2021-08-13

diff --git a/src/util/virpci.c b/src/util/virpci.c
index 0b1222373e..a54be60da0 100644
--- a/src/util/virpci.c
+++ b/src/util/virpci.c
@@ -2424,9 +2424,9 @@ virPCIDeviceAddressGetSysfsFile(virPCIDeviceAddressPtr addr,
  * virPCIGetNetName:
  * @device_link_sysfs_path: sysfs path to the PCI device
  * @idx: used to choose which netdev when there are several
- *       (ignored if physPortID is set)
+ *       (ignored if physPortID is set or physPortName is available)
  * @physPortID: match this string in the netdev's phys_port_id
- *       (or NULL to ignore and use idx instead)
+ *       (or NULL to ignore and use phys_port_name or idx instead)
  * @netname: used to return the name of the netdev
  *       (set to NULL (but returns success) if there is no netdev)
  *
@@ -2461,6 +2461,14 @@ virPCIGetNetName(const char *device_link_sysfs_path,
     }
 
     while (virDirRead(dir, &entry, pcidev_sysfs_net_path) > 0) {
+        /* save the first entry we find to use as a failsafe
+         * in case we don't match the phys_port_id. This is
+         * needed because some NIC drivers (e.g. i40e)
+         * implement phys_port_id for PFs, but not for VFs
+         */
+        if (!firstEntryName)
+            firstEntryName = g_strdup(entry->d_name);
+
         /* if the caller sent a physPortID, compare it to the
          * physportID of this netdev. If not, look for entry[idx].
          */
@@ -2471,19 +2479,35 @@ virPCIGetNetName(const char *device_link_sysfs_path,
             /* if this one doesn't match, keep looking */
             if (STRNEQ_NULLABLE(physPortID, thisPhysPortID)) {
                 VIR_FREE(thisPhysPortID);
-                /* save the first entry we find to use as a failsafe
-                 * in case we don't match the phys_port_id. This is
-                 * needed because some NIC drivers (e.g. i40e)
-                 * implement phys_port_id for PFs, but not for VFs
-                 */
-                if (!firstEntryName)
-                    firstEntryName = g_strdup(entry->d_name);
-
                 continue;
             }
         } else {
-            if (i++ < idx)
-                continue;
+            /* Most switch devices use phys_port_name instead of
+             * phys_port_id.
+             * NOTE: VFs' representors net devices can be linked to PF's PCI
+             * device, which mean that there'll be multiple net devices
+             * instances and to get a proper net device need to match on
+             * specific regex.
+             * To get PF netdev, for ex., used following regex:
+             * "(p[0-9]+$)|(p[0-9]+s[0-9]+$)"
+             * or to get exact VF's netdev next regex is used:
+             * "pf0vf1$"
+             */
+            g_autofree char *thisPhysPortName = NULL;
+            if (virNetDevGetPhysPortName(entry->d_name, &thisPhysPortName) < 0)
+                goto cleanup;
+
+            if (thisPhysPortName) {
+
+                /* if this one doesn't match, keep looking */
+                if (!virStringMatch(thisPhysPortName, VIR_PF_PHYS_PORT_NAME_REGEX))
+                    continue;
+
+            } else {
+
+                if (i++ < idx)
+                    continue;
+            }
         }
 
         *netname = g_strdup(entry->d_name);
@@ -2493,24 +2517,21 @@ virPCIGetNetName(const char *device_link_sysfs_path,
     }
 
     if (ret < 0) {
-        if (physPortID) {
-            if (firstEntryName) {
-                /* we didn't match the provided phys_port_id, but this
-                 * is probably because phys_port_id isn't implemented
-                 * for this NIC driver, so just return the first
-                 * (probably only) netname we found.
-                 */
-                *netname = firstEntryName;
-                firstEntryName = NULL;
-                ret = 0;
-            } else {
-                virReportError(VIR_ERR_INTERNAL_ERROR,
-                               _("Could not find network device with "
-                                 "phys_port_id '%s' under PCI device at %s"),
-                               physPortID, device_link_sysfs_path);
-            }
+        if (firstEntryName) {
+            /* we didn't match the provided phys_port_id / find a
+             * phys_port_name matching VIR_PF_PHYS_PORT_NAME_REGEX / find
+             * as many net devices as the value of idx, but this is
+             * probably because phys_port_id / phys_port_name isn't
+             * implemented for this NIC driver, so just return the first
+             * (probably only) netname we found.
+             */
+            *netname = g_steal_pointer(&firstEntryName);
+            ret = 0;
         } else {
-            ret = 0; /* no netdev at the given index is *not* an error */
+            virReportError(VIR_ERR_INTERNAL_ERROR,
+                           _("Could not find any network device under PCI device at %s"),
+                           device_link_sysfs_path);
+            ret = -1;
         }
     }
  cleanup:
diff --git a/src/util/virpci.h b/src/util/virpci.h
index f6796fc422..e47c766918 100644
--- a/src/util/virpci.h
+++ b/src/util/virpci.h
@@ -49,6 +49,11 @@ struct _virZPCIDeviceAddress {
 
 #define VIR_PCI_DEVICE_ADDRESS_FMT "%04x:%02x:%02x.%d"
 
+/* Represents format of PF's phys_port_name in switchdev mode:
+ * 'p%u' or 'p%us%u'. New line checked since value is readed from sysfs file.
+ */
+#define VIR_PF_PHYS_PORT_NAME_REGEX  "(p[0-9]+$)|(p[0-9]+s[0-9]+$)"
+
 struct _virPCIDeviceAddress {
     unsigned int domain;
     unsigned int bus;