Thursday, June 14, 2018 11:35 AM, Adrien Mazarguil:

Subject: [PATCH v2 3/7] net/mlx5: split PCI from generic probing code

All the generic probing code needs is an IB device. While this device is
currently supplied by a PCI lookup, other methods will be added soon.

This patch divides the original function, which has become huge over time, as
follows:

1. PCI-specific (mlx5_pci_probe()).
2. All ports of a Verbs device (mlx5_dev_spawn()).
3. A given port of a Verbs device (mlx5_dev_spawn_one()).

(Patch based on prior work from Yuanhan Liu)

Signed-off-by: Adrien Mazarguil <redacted>
--
v2 changes:

- Fixed device naming. A port suffix is now appended only if several IB
  ports happen to be detected.
- Added separate message to distinguish missing kernel drivers from other
  initialization errors, as it was confusing.

[...]

+/**
+ * DPDK callback to register a PCI device.
+ *
+ * This function creates an Ethernet device for each port of a given
+ * PCI device.
+ *
+ * @param[in] pci_drv
+ *   PCI driver structure (mlx5_driver).
+ * @param[in] pci_dev
+ *   PCI device information.
+ *
+ * @return
+ *   0 on success, a negative errno value otherwise and rte_errno is set.
+ */
+static int
+mlx5_pci_probe(struct rte_pci_driver *pci_drv __rte_unused,
+	       struct rte_pci_device *pci_dev) {
+	struct ibv_device **ibv_list;
+	struct rte_eth_dev **eth_list = NULL;
+	int vf;
+	int ret;
+
+	assert(pci_drv == &mlx5_driver);
+	switch (pci_dev->id.device_id) {
+	case PCI_DEVICE_ID_MELLANOX_CONNECTX4VF:
+	case PCI_DEVICE_ID_MELLANOX_CONNECTX4LXVF:
+	case PCI_DEVICE_ID_MELLANOX_CONNECTX5VF:
+	case PCI_DEVICE_ID_MELLANOX_CONNECTX5EXVF:
+		vf = 1;
+		break;
+	default:
+		vf = 0;
+	}

Even though I couldn't find any functional bug, I think it is logically more correct to determine if pci device is vf after we know this is Mellanox device. 
Meaning the above block should be ...

+	errno = 0;
+	ibv_list = mlx5_glue->get_device_list(&ret);
+	if (!ibv_list) {
+		rte_errno = errno ? errno : ENOSYS;
+		DRV_LOG(ERR, "cannot list devices, is ib_uverbs loaded?");
 		return -rte_errno;
 	}
-	return 0;
+	while (ret-- > 0) {
+		struct rte_pci_addr pci_addr;
+
+		DRV_LOG(DEBUG, "checking device \"%s\"", ibv_list[ret]-

quoted

name);

+		if (mlx5_ibv_device_to_pci_addr(ibv_list[ret], &pci_addr))
+			continue;
+		if (pci_dev->addr.domain != pci_addr.domain ||
+		    pci_dev->addr.bus != pci_addr.bus ||
+		    pci_dev->addr.devid != pci_addr.devid ||
+		    pci_dev->addr.function != pci_addr.function)
+			continue;
+		DRV_LOG(INFO, "PCI information matches, using device
\"%s\"",
+			ibv_list[ret]->name);
+		break;
+	}

Here. 

+	if (ret >= 0)
+		eth_list = mlx5_dev_spawn(&pci_dev->device, ibv_list[ret],
vf);
+	mlx5_glue->free_device_list(ibv_list);
+	if (!ret) {
+		DRV_LOG(WARNING,
+			"no Verbs device matches PCI device " PCI_PRI_FMT
","
+			" are kernel drivers loaded?",
+			pci_dev->addr.domain, pci_dev->addr.bus,
+			pci_dev->addr.devid, pci_dev->addr.function);
+		rte_errno = ENOENT;
+		ret = -rte_errno;
+	} else if (!eth_list || !*eth_list) {
+		DRV_LOG(ERR,
+			"probe of PCI device " PCI_PRI_FMT " aborted after"
+			" encountering an error: %s",
+			pci_dev->addr.domain, pci_dev->addr.bus,
+			pci_dev->addr.devid, pci_dev->addr.function,
+			strerror(rte_errno));
+		ret = -rte_errno;
+	} else {
+		for (ret = 0; eth_list[ret]; ++ret) {
+			rte_eth_copy_pci_info(eth_list[ret], pci_dev);
+			rte_eth_dev_probing_finish(eth_list[ret]);
+		}
+		ret = 0;
+	}
+	free(eth_list);
+	return ret;
 }

 static const struct rte_pci_id mlx5_pci_id_map[] = {
--
2.11.0