Re: [dpdk-dev] [PATCH v2 0/3] ethdev: configure SR-IOV VF from host

[Ilya Maximets <i.maximets@ovn.org>]

On 01.11.2019 1:24, Thomas Monjalon wrote:
> 30/10/2019 10:24, Jerin Jacob:
>> On Wed, Oct 30, 2019 at 12:52 PM Shahaf Shuler <shahafs@mellanox.com> wrote:
>>> Wednesday, October 30, 2019 6:09 AM, Jerin Jacob:
>>>> Subject: Re: [dpdk-dev] [PATCH v2 0/3] ethdev: configure SR-IOV VF from
>>>> host
>>>>
>>>> On Wed, Oct 30, 2019 at 12:21 AM Thomas Monjalon
>>>> <thomas@monjalon.net> wrote:
>>>>>
>>>>> In a virtual environment, the network controller may have to configure
>>>>> some SR-IOV VF parameters for security reasons.
>>>>
>>>> Just to understand, Could you explain more details/examples for security
>>>> reasons?
>>>>
>>>>>
>>>>> When the PF (host port) is driven by DPDK (OVS-DPDK case), we face two
>>>>> different cases:
>>>>>      - driver is bifurcated (Mellanox case),
>>>>>        so the VF can be configured via the kernel.
>>>>>      - driver is on top of UIO or VFIO, so DPDK API is required,
>>>>
>>>> Not true. Both UIO and VFIO are NOT allowed to create SRIOV VF from the
>>>> PF device.
>>>> It is only allowed through igb-uio out of tree driver without iommu support.
>>>
>>> Per my understanding Thomas proposal is not to create the VFs
>>> from the PF device. it is to configure their network attributes
>>> from the PF after they have been created.
>>
>> Yes. My question is without creating the VF, How do you control them?
> 
> We can create the VF via the kernel PF driver, before binding the PF to VFIO.

AFAIK, this is not possible. VFs are gone as soon as you're unbinding kernel
PF driver.  And after binding of vfio-pci you can no longer create VFs.

I tried to check some representor functionality about 2 months ago and didn't
find a way to enable VFs on Intel NICs if PF is under control of vfio-pci.

Best regards, Ilya Maximets.