[ovs-dev] [PATCH v1] doc: Add "Representors" topic document

[Ophir Munk]

> -----Original Message-----
> From: Ilya Maximets <i.maximets at samsung.com>
> Sent: Thursday, February 14, 2019 12:47 PM
> To: Ian Stokes <ian.stokes at intel.com>; Ophir Munk
> <ophirmu at mellanox.com>; ovs-dev at openvswitch.org
> Cc: Olga Shern <olgas at mellanox.com>; Kevin Traynor
> <ktraynor at redhat.com>; Asaf Penso <asafp at mellanox.com>; Thomas
> Monjalon <thomas at monjalon.net>
> Subject: Re: [PATCH v1] doc: Add "Representors" topic document
> 
> On 13.02.2019 19:39, Ian Stokes wrote:
> > On 2/13/2019 8:14 AM, Ophir Munk wrote:
> >>
> >>
> >>> -----Original Message-----
> >>>> -----Original Message-----
> >>>> From: Ian Stokes <ian.stokes at intel.com>
> >>>> Sent: Tuesday, February 12, 2019 7:17 PM
> >>>> To: Ilya Maximets <i.maximets at samsung.com>; Ophir Munk
> >>>> <ophirmu at mellanox.com>; ovs-dev at openvswitch.org
> >>>> Cc: Olga Shern <olgas at mellanox.com>; Kevin Traynor
> >>>> <ktraynor at redhat.com>; Asaf Penso <asafp at mellanox.com>; Thomas
> >>>> Monjalon <thomas at monjalon.net>
> >>>> Subject: Re: [PATCH v1] doc: Add "Representors" topic document
> >>>>
> >>>> On 2/12/2019 1:15 PM, Ilya Maximets wrote:
> >>>>> On 11.02.2019 3:01, Ophir Munk wrote:
> >>>>>> This details how to configure representors ports.
> >>>>>>
> >>>>>> Signed-off-by: Ophir Munk <ophirmu at mellanox.com>
> >>>>>> ---
> >>>>>>    Documentation/topics/dpdk/phy.rst | 80
> >>>> +++++++++++++++++++++++++++++++++++++++
> >>>>>>    1 file changed, 80 insertions(+)
> >>>>>>
> >> ...
> >>>>>> +
> >>>>>> +Representors
> >>>>>> +------------
> >>> .....
> >>>>>> +
> >>>>>> +.. important::
> >>>>>> +
> >>>>>> +   Representors ports are configured prior to OVS invocation and
> >>>> independently
> >>>>>> +   of it, or by other means as well. Please consult a NIC vendor
> >>>> instructions
> >>>>>> +   on how to establish representors.
> >>>>>
> >>>>> It'll be good to have configuration example for at least one
> >>>>> commonly used NIC (ixgbe/i40e ?). Or maybe a link to the docs
> >>>>> where the process
> >>>> described.
> >>>>>
> >>>>> What do you think ?
> >>>>> Ian, maybe you could add some example, since you have already
> >>>>> tried it in
> >>>> practice?
> >>>>>
> >>>>
> >>>> Good call, I'll draw up an incremental and post here, if acceptable
> >>>> we can roll it into the same patch.
> >>>>
> >>>
> >>> In addition to Ian drawing - please find a link which details how to
> >>> create VFs for ConnectX-4 5 or 6 NICs:
> >>>
> https://emea01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fd
> >>> ocs.openstack.org%2Fneutron%2Frocky%2Fadmin%2Fconfig-ovs-
> offload.htm
> >>>
> l&amp;data=02%7C01%7Cophirmu%40mellanox.com%7C53cb5ae93dbd423a
> 481608
> >>>
> d69269d466%7Ca652971c7d2e4d9ba6a4d149256f461b%7C0%7C0%7C6368573
> 80568
> >>>
> 209851&amp;sdata=Uz60DuaXDBOk7%2BkSuEG6iGk4qAOg3OfkYBj2BbUKK5
> k%3D&am
> >>> p;reserved=0 section "Create Compute virtual functions".
> >>> I will send an updated v2 with this reference.
> >>>
> >>>> Ian
> >>
> >> After giving it more thought - IMHO it's better to add a new document
> under howto/ where NIC vendors could specify their configuration for
> representors setup.
> >> We can then refer from this document to the new one.
> >> Ilay, Ian - what do you think?
> >>
> >
> > Hmmm, for ixgbe/i40e that are bound to a dpdk compatible driver it's
> > just a case of creating the vf with something similar to below
> >
> > echo 1 > /sys/bus/pci/devices/0000\:05\:00.0/max_vfs
> >
> > And then adding it as described above
> >
> > ovs-vsctl add-port br0 dpdk-rep5 -- set Interface dpdk-rep0 type=dpdk
> > \ options:dpdk-devargs=0000:05:00.0,representor=[0]
> >
> > I'm not sure that it would warrant it's own document for those devices,
> how does it compare to the mellanox creation of vfs? Is that more complex
> or different?
> 
> I know that to make representors appear as linux interfaces (for using them
> in OVS kernel datapath, for example) you need to turn the PF into
> "switchdev"
> mode. Probably, the same needed with DPDK.
> 

Exactly. For Mellanox NICs we should explicitly turn the PF into "switchdev".
Those are additional commands, not mentioned here.

> Anyway, The instructions for most of NICs, I guess, should be "just echo
> number of VFs to 'max_vfs' sysfs knob". We may add this information right
> here and make a remark that some NICs may require additional steps. 

Agreed. I will add them in v2.

> We
> may also point to the openstack ovs-offload guide, first parts of it describes
> how to configure representors with Mellanox NICs.

Agreed. In v2 I will add the link to the openstack ovs-offload guilde.

> IMHO, this amount of information should be enough and it does not deserve
> a separate manual.

Agreed. Many thanks for the prompt review.