net/mlx5: enhance SR-IOV detection

SR-IOV mode is currently set when dealing with VF devices. PF devices must
be taken into account as well if they have active VFs.

Signed-off-by: Nelio Laranjeiro <nelio.laranjeiro@6wind.com>
Signed-off-by: Adrien Mazarguil <adrien.mazarguil@6wind.com>

drivers/net/mlx5/mlx5.c

@@ -260,7 +260,7 @@ mlx5_pci_devinit(struct rte_pci_driver *pci_drv, struct rte_pci_device *pci_dev)
 	int err = 0;
 	struct ibv_context *attr_ctx = NULL;
 	struct ibv_device_attr device_attr;
-	unsigned int vf;
+	unsigned int sriov;
 	unsigned int mps;
 	int idx;
 	int i;
@@ -303,17 +303,17 @@ mlx5_pci_devinit(struct rte_pci_driver *pci_drv, struct rte_pci_device *pci_dev)
 		    (pci_dev->addr.devid != pci_addr.devid) ||
 		    (pci_dev->addr.function != pci_addr.function))
 			continue;
-		vf = ((pci_dev->id.device_id ==
+		sriov = ((pci_dev->id.device_id ==
 		       PCI_DEVICE_ID_MELLANOX_CONNECTX4VF) ||
 		      (pci_dev->id.device_id ==
 		       PCI_DEVICE_ID_MELLANOX_CONNECTX4LXVF));
 		/* Multi-packet send is only supported by ConnectX-4 Lx PF. */
 		mps = (pci_dev->id.device_id ==
 		       PCI_DEVICE_ID_MELLANOX_CONNECTX4LX);
-		INFO("PCI information matches, using device \"%s\" (VF: %s,"
+		INFO("PCI information matches, using device \"%s\""
-		     " MPS: %s)",
+		     " (SR-IOV: %s, MPS: %s)",
 		     list[i]->name,
-		     vf ? "true" : "false",
+		     sriov ? "true" : "false",
 		     mps ? "true" : "false");
 		attr_ctx = ibv_open_device(list[i]);
 		err = errno;
@@ -351,6 +351,7 @@ mlx5_pci_devinit(struct rte_pci_driver *pci_drv, struct rte_pci_device *pci_dev)
 		struct ibv_exp_device_attr exp_device_attr;
 #endif /* HAVE_EXP_QUERY_DEVICE */
 		struct ether_addr mac;
+		uint16_t num_vfs = 0;
 
 #ifdef HAVE_EXP_QUERY_DEVICE
 		exp_device_attr.comp_mask =
@@ -464,7 +465,8 @@ mlx5_pci_devinit(struct rte_pci_driver *pci_drv, struct rte_pci_device *pci_dev)
 		priv->ind_table_max_size = RSS_INDIRECTION_TABLE_SIZE;
 #endif /* HAVE_EXP_QUERY_DEVICE */
 
-		priv->vf = vf;
+		priv_get_num_vfs(priv, &num_vfs);
+		priv->sriov = (num_vfs || sriov);
 		priv->mps = mps;
 		/* Allocate and register default RSS hash keys. */
 		priv->rss_conf = rte_calloc(__func__, hash_rxq_init_n,

drivers/net/mlx5/mlx5.h

@@ -104,7 +104,7 @@ struct priv {
 	unsigned int hw_vlan_strip:1; /* VLAN stripping is supported. */
 	unsigned int hw_fcs_strip:1; /* FCS stripping is supported. */
 	unsigned int hw_padding:1; /* End alignment padding is supported. */
-	unsigned int vf:1; /* This is a VF device. */
+	unsigned int sriov:1; /* This is a VF or PF with VF devices. */
 	unsigned int mps:1; /* Whether multi-packet send is supported. */
 	unsigned int pending_alarm:1; /* An alarm is pending. */
 	/* RX/TX queues. */
@@ -172,6 +172,7 @@ struct priv *mlx5_get_priv(struct rte_eth_dev *dev);
 int mlx5_is_secondary(void);
 int priv_get_ifname(const struct priv *, char (*)[IF_NAMESIZE]);
 int priv_ifreq(const struct priv *, int req, struct ifreq *);
+int priv_get_num_vfs(struct priv *, uint16_t *);
 int priv_get_mtu(struct priv *, uint16_t *);
 int priv_set_flags(struct priv *, unsigned int, unsigned int);
 int mlx5_dev_configure(struct rte_eth_dev *);

drivers/net/mlx5/mlx5_ethdev.c

@@ -361,6 +361,38 @@ priv_ifreq(const struct priv *priv, int req, struct ifreq *ifr)
 	return ret;
 }
 
+/**
+ * Return the number of active VFs for the current device.
+ *
+ * @param[in] priv
+ *   Pointer to private structure.
+ * @param[out] num_vfs
+ *   Number of active VFs.
+ *
+ * @return
+ *   0 on success, -1 on failure and errno is set.
+ */
+int
+priv_get_num_vfs(struct priv *priv, uint16_t *num_vfs)
+{
+	/* The sysfs entry name depends on the operating system. */
+	const char **name = (const char *[]){
+		"device/sriov_numvfs",
+		"device/mlx5_num_vfs",
+		NULL,
+	};
+	int ret;
+
+	do {
+		unsigned long ulong_num_vfs;
+
+		ret = priv_get_sysfs_ulong(priv, *name, &ulong_num_vfs);
+		if (!ret)
+			*num_vfs = ulong_num_vfs;
+	} while (*(++name) && ret);
+	return ret;
+}
+
 /**
  * Get device MTU.
  *

drivers/net/mlx5/mlx5_rxtx.c

@@ -507,7 +507,7 @@ tx_burst_sg(struct txq *txq, unsigned int segs, struct txq_elt *elt,
 		}
 		/* Update SGE. */
 		sge->addr = rte_pktmbuf_mtod(buf, uintptr_t);
-		if (txq->priv->vf)
+		if (txq->priv->sriov)
 			rte_prefetch0((volatile void *)
 				      (uintptr_t)sge->addr);
 		sge->length = DATA_LEN(buf);
@@ -662,7 +662,7 @@ mlx5_tx_burst(void *dpdk_txq, struct rte_mbuf **pkts, uint16_t pkts_n)
 			length = DATA_LEN(buf);
 			/* Update element. */
 			elt->buf = buf;
-			if (txq->priv->vf)
+			if (txq->priv->sriov)
 				rte_prefetch0((volatile void *)
 					      (uintptr_t)addr);
 			/* Prefetch next buffer data. */