[dpdk-dev] [PATCH] vfio: make container open error non-fatal

[Bruce Richardson <bruce.richardson@intel.com>]

When setting up an app to run using the uio driver, errors caused by
VFIO failures should not abruptly cause the app to fail.

Example: on a board with 8 ports bound to igb_uio module, and no VFIO
configuration, a testpmd run currently fails with:

EAL:   cannot open VFIO container!
EAL:   0000:04:00.0 cannot open VFIO container!
EAL: Error - exiting with code: 1
  Cause: Requested device 0000:04:00.0 cannot be used

With this patch applied, the problem with VFIO is ignored and testpmd
successfully starts up - with ignored errors with vfio - as below:

EAL: PCI device 0000:04:00.0 on NUMA socket 0
EAL:   probe driver: 8086:1521 rte_igb_pmd
EAL:   unknown IOMMU driver!
EAL:   0000:04:00.0 cannot open VFIO container!
EAL:   0000:04:00.0 not managed by UIO driver, skipping
<...scan results for other ports skipped...>
EAL: PCI device 0000:8e:00.0 on NUMA socket 1
EAL:   probe driver: 8086:154a rte_ixgbe_pmd
EAL:   unknown IOMMU driver!
EAL:   0000:8e:00.0 cannot open VFIO container!
EAL:   PCI memory mapped at 0x7ff4ff5fa000
EAL:   PCI memory mapped at 0x7ff4ff5f6000
EAL: PCI device 0000:8e:00.1 on NUMA socket 1
EAL:   probe driver: 8086:154a rte_ixgbe_pmd
EAL:   unknown IOMMU driver!
EAL:   0000:8e:00.1 cannot open VFIO container!
EAL:   PCI memory mapped at 0x7ff4ff4f6000
EAL:   PCI memory mapped at 0x7ff4ff4f2000
Interactive-mode selected
Configuring Port 0 (socket 0)
<...other 7 ports ...>
Checking link statuses...
Port 0 Link Up - speed 10000 Mbps - full-duplex
Port 1 Link Down
Port 2 Link Up - speed 10000 Mbps - full-duplex
Port 3 Link Down
Port 4 Link Up - speed 10000 Mbps - full-duplex
Port 5 Link Down
Port 6 Link Up - speed 10000 Mbps - full-duplex
Port 7 Link Down
Done
testpmd>

This issue is introduced by the VFIO patch set addition, specifically
commit ff0b67d1.

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
---
 lib/librte_eal/linuxapp/eal/eal_pci_vfio.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/librte_eal/linuxapp/eal/eal_pci_vfio.c b/lib/librte_eal/linuxapp/eal/eal_pci_vfio.c
index 4de6061..4af38f6 100644
--- a/lib/librte_eal/linuxapp/eal/eal_pci_vfio.c
+++ b/lib/librte_eal/linuxapp/eal/eal_pci_vfio.c
@@ -528,7 +528,7 @@ pci_vfio_map_resource(struct rte_pci_device *dev)
 		int vfio_container_fd = pci_vfio_get_container_fd();
 		if (vfio_container_fd < 0) {
 			RTE_LOG(ERR, EAL, "  %s cannot open VFIO container!\n", pci_addr);
-			return -1;
+			return 1;
 		}
 
 		vfio_cfg.vfio_container_fd = vfio_container_fd;
-- 
1.9.3