[dpdk-dev] Debugging EAL PCI / Driver Init

Matthew Hall mhall at mhcomputing.net
Sat Aug 2 17:43:10 CEST 2014

Also, when using the separate libraries the problem still happens:

-lethdev -lrte_cfgfile -lrte_cmdline -lrte_distributor -lrte_hash 
-lrte_ip_frag -lrte_lpm -lrte_malloc -lrte_mbuf -lrte_mempool -lrte_pmd_e1000 
-lrte_pmd_pcap -lrte_pmd_virtio_uio -lrte_pmd_vmxnet3_uio -lrte_port 
-lrte_ring -lrte_table -lrte_timer -lrte_eal -lbsd -ldl -lpcap -lpthread

So it seems there is a special order or link technique which must be used, or 
rte_eal's PCI code won't be able to load the PMD's during PCI probing. Is it 
documented anywhere how to get that to work?


On Sat, Aug 02, 2014 at 08:29:04AM -0700, Matthew Hall wrote:
> I did a bit more experimentation and found the following. If I unmark the 
> rte_igb_pmd_init function as static, and call it directly from my code, the 
> driver will load, and the port count increments to 2:
> EAL: PCI device 0000:01:00.0 on NUMA socket -1
> EAL:   probe driver: 8086:1521 rte_igb_pmd
> EAL:   PCI memory mapped at 0x7f09d45f2000
> EAL:   PCI memory mapped at 0x7f09d4730000
> PMD: eth_igb_dev_init(): port_id 0 vendorID=0x8086 deviceID=0x1521
> EAL: PCI device 0000:01:00.1 on NUMA socket -1
> EAL:   probe driver: 8086:1521 rte_igb_pmd
> EAL:   PCI memory mapped at 0x7f09d0f00000
> EAL:   PCI memory mapped at 0x7f09d472c000
> PMD: eth_igb_dev_init(): port_id 1 vendorID=0x8086 deviceID=0x1521
> So it seems like when you enable these options:
> # Combine to one single library
> CONFIG_RTE_LIBNAME="intel_dpdk"
> You don't really get a working DPDK inside of "-lintel_dpdk". Someone 
> suggested linking with "-Xlinker -lintel_dpdk" but that didn't seem to help.
> Is there a secret to getting a single integrated static library, where all of 
> the PMD's end up in the PCI driver list so rte_eal_pci_probe can find them? Or 
> some secret to linking against the combined library which works properly?
> Matthew.
> On Fri, Aug 01, 2014 at 10:51:38AM -0700, Matthew Hall wrote:
> > Hello,
> > 
> > I am running into a problem where Eth driver init works fine in a sample app 
> > and finds my NICs, and the NICs appear in rte_eal_pci_dump(stdout) but they 
> > don't show up in rte_eth_dev_count() even after rte_eal_pci_probe() is called 
> > the same as the sample apps, so my app won't boot.
> > 
> > I have a lot of experience using the older versions of the DPDK where you had 
> > to call the PMD init functions manually but no experience with the later 
> > versions where the DPDK is supposed to init the PMDs itself automatically.
> > 
> > What do I have to do to dump the most possible debug output on why the driver 
> > list for my PCI devices always seems empty? Any places I should look to see 
> > the issue? Maybe I didn't link it together with the right DPDK libs? I used 
> > the combined DPDK static lib libintel_dpdk.a to make things simpler as I had 
> > seen recommended in various places.
> > 
> > Thanks,
> > Matthew.

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