mlx4: avoid init errors when kernel modules are not loaded

Mimic UIO/VFIO drivers behavior by not causing errors when a device cannot
be initialized due to missing or mismatching kernel modules. Display helpful
messages instead, such as:

 [...]
 EAL: PCI device 0000:83:00.0 on NUMA socket 1
 EAL:   probe driver: 15b3:1007 librte_pmd_mlx4
 PMD: librte_pmd_mlx4: PCI information matches, using device "mlx4_0" (VF: false)
 PMD: librte_pmd_mlx4: cannot use device, are drivers up to date?
 EAL: PCI device 0000:84:00.0 on NUMA socket 1
 EAL:   probe driver: 15b3:1007 librte_pmd_mlx4
 PMD: librte_pmd_mlx4: PCI information matches, using device "mlx4_1" (VF: false)
 PMD: librte_pmd_mlx4: cannot use device, are drivers up to date?
 EAL: No probed ethernet devices
 [...]

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

diff --git a/lib/librte_pmd_mlx4/mlx4.c b/lib/librte_pmd_mlx4/mlx4.c
index b5774c4..3a45746 100644 (file)
--- a/lib/librte_pmd_mlx4/mlx4.c
+++ b/lib/librte_pmd_mlx4/mlx4.c
@@ -4423,6 +4423,10 @@ mlx4_pci_devinit(struct rte_pci_driver *pci_drv, struct rte_pci_device *pci_dev)
        list = ibv_get_device_list(&i);
        if (list == NULL) {
                assert(errno);
+               if (errno == ENOSYS) {
+                       WARN("cannot list devices, is ib_uverbs loaded?");
+                       return 0;
+               }
                return -errno;
        }
        assert(i >= 0);
@@ -4451,9 +4455,15 @@ mlx4_pci_devinit(struct rte_pci_driver *pci_drv, struct rte_pci_device *pci_dev)
                break;
        }
        if (attr_ctx == NULL) {
-               if (err == 0)
-                       err = ENODEV;
                ibv_free_device_list(list);
+               switch (err) {
+               case 0:
+                       WARN("cannot access device, is mlx4_ib loaded?");
+                       return 0;
+               case EINVAL:
+                       WARN("cannot use device, are drivers up to date?");
+                       return 0;
+               }
                assert(err > 0);
                return -err;
        }