[dpdk-dev] vfio: failed to select IOMMU type

[Burakov, Anatoly]

> From: Andrew Rybchenko [mailto:arybchenko at solarflare.com]
> Sent: Saturday, April 1, 2017 11:47 AM
> To: dev at dpdk.org; Alejandro Lucero <alejandro.lucero at netronome.com>
> Cc: Burakov, Anatoly <anatoly.burakov at intel.com>
> Subject: vfio: failed to select IOMMU type
> 
> Hi,
> 
> after the following commit (it was picked up by dpdk-next-net recently), I
> have problems with VFIO:
> ===
> commit 94c0776b1badd1ee715d60f07391058f23494365
> Author: Alejandro Lucero <alejandro.lucero at netronome.com>
> Date:   Wed Mar 29 10:54:50 2017 +0100
> 
>      vfio: support hotplug
> 
>      Current device hotplug is just supported by UIO managed devices.
>      This patch adds same functionality with VFIO.
> 
>      It has been validated through tests using IOMMU and also with
>      VFIO and no-iommu mode.
> 
>      Signed-off-by: Alejandro Lucero <alejandro.lucero at netronome.com>
>      Acked-by: Anatoly Burakov <anatoly.burakov at intel.com> ===
> 
> The second PCI function fails to bind:
> # testpmd -w 06:00.0 -w 06:00.1 -c 0xc -n 4  -- --rxd=512 --txd=512 --crc-strip -
> -disable-hw-vlan-filter --disable-hw-vlan-strip
> EAL: Detected 16 lcore(s)
> EAL: 2048 hugepages of size 2097152 reserved, but no mounted hugetlbfs
> found for that size
> EAL: Probing VFIO support...
> EAL: VFIO support initialized
> EAL: PCI device 0000:06:00.0 on NUMA socket 0
> EAL:   probe driver: 1924:a03 net_sfc_efx
> EAL:   using IOMMU type 1 (Type 1)
> EAL: Ignore mapping IO port bar(0) addr: 2101
> EAL: PCI device 0000:06:00.1 on NUMA socket 0
> EAL:   probe driver: 1924:a03 net_sfc_efx
> EAL:   0000:06:00.1 failed to select IOMMU type
> EAL: Requested device 0000:06:00.1 cannot be used
> EAL: Requested device 0000:7f:08.0 cannot be used
> EAL: Requested device 0000:7f:08.2 cannot be used
> EAL: Requested device 0000:7f:08.3 cannot be used ...
> 
> Also I don't understand why it spams about many other PCI functions taking
> into account that just 2 are specified in whitelist.
> 
> I've bisected to find commit when the problem appears, but has not found
> root cause yet.
> 
> Andrew.

Hi Andrew,

It would be interesting to know what was wrong there. The whitelist issue is surprising, and from the logs it seems like EAL is trying to set up DMA mappings multiple times. Posting a more detailed log would be very helpful in tracking down the issue as well. I have tested that code with ixgbe devices, so I'm not too sure what can go wrong there.

Thanks,
Anatoly