Re: [dpdk-dev] [PATCH] igb_uio: map dummy dma forcing iommu domain attachment

[Ferruh Yigit <ferruh.yigit@intel.com>]

On 2/10/2017 7:03 PM, Ferruh Yigit wrote:
> On 2/8/2017 11:54 AM, Alejandro Lucero wrote:
>> Hi Ferruh,
>>
>> On Tue, Feb 7, 2017 at 3:59 PM, Ferruh Yigit <ferruh.yigit@intel.com
>> <mailto:ferruh.yigit@intel.com>> wrote:
>>
>>     Hi Alejandro,
>>
>>     On 1/18/2017 12:27 PM, Alejandro Lucero wrote:
>>     > For using a DPDK app when iommu is enabled, it requires to
>>     > add iommu=pt to the kernel command line. But using igb_uio driver
>>     > makes DMAR errors because the device has not an IOMMU domain.
>>
>>     Please help to understand the scope of the problem,
>>
>>
>> After reading your reply, I realize I could have explained it better.
>> First of all, this is related to SRIOV, exactly when the VFs are created.
>>  
>>
>>     1- How can you re-produce the problem?
>>
>>
>> Using a VF from a Intel card by a DPDK app in the host and a kernel >=
>> 3.15. Although usually VFs are assigned to VMs, it could also be an
>> option to use VFs by the host. 
>>
>> BTW, I did not try to reproduce the problem with an Intel card. I
>> triggered this problem with an NFP, but because the problem behind, I
>> bet that is going to happen for an Intel one as well.
> 
> I can able to reproduce the problem with ixgbe, by using VF on the host.
> 
> And I verified your patch fixes it, it cause device attached to a vfio
> group.

I want to send this in a separate mail, since not directly related to
your patch, but while I was testing with vfio-pci I get lower numbers
comparing to the igb_uio, which is unexpected AFAIK.

Most probably I am doing something wrong, but I would like to ask if are
you observing same behavior?

Thanks,
ferruh