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Message-ID: <20200320073555.GE11304@nanopsycho.orion>
Date: Fri, 20 Mar 2020 08:35:55 +0100
From: Jiri Pirko <jiri@...nulli.us>
To: Jakub Kicinski <kuba@...nel.org>
Cc: netdev@...r.kernel.org, davem@...emloft.net, parav@...lanox.com,
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Subject: Re: [RFC] current devlink extension plan for NICs
Fri, Mar 20, 2020 at 04:32:53AM CET, kuba@...nel.org wrote:
>On Thu, 19 Mar 2020 20:27:19 +0100 Jiri Pirko wrote:
>> Hi all.
>>
>> First, I would like to apologize for very long email. But I think it
>> would be beneficial to the see the whole picture, where we are going.
>>
>> Currently in Mellanox we are working on several features with need of
>> extension of the current devlink infrastructure. I took a stab at
>> putting it all together in a single txt file, inlined below.
>
>Does it make sense to transcribe this (modulo discussion)
>as documentation? I noticed you don't use rst notation.
That is a plan. I want to convert it in parts to the documentation.
>
>> Most of the stuff is based on a new object called "slice" (called
>> "subdev" originally in Yuval's patchsets sent some while ago).
>>
>> The text describes how things should behave and provides a draft
>> of user facing console input/outputs. I think it is important to clear
>> that up before we go in and implement the devlink core and
>> driver pieces.
>>
>> I would like to ask you to read this and comment. Especially, I would
>> like to ask vendors if what is described fits the needs of your
>> NIC/e-switch.
>>
>> Please note that something is already implemented, but most of this
>> isn't (see "what needs to be implemented" section).
>>
>>
>>
>>
>> ==================================================================
>> || ||
>> || Overall illustration of example setup ||
>> || ||
>> ==================================================================
>>
>> Note that there are 2 hosts in the picture. Host A may be the smartnic host,
>> Host B may be one of the hosts which gets PF. Also, you might omit
>> the Host B and just see Host A like an ordinary nic in a host.
>
>Could you enumerate the use scenarios for the SmartNIC?
>
>Is SmartNIC always "in-line", i.e. separating the host from the network?
As far as I know, it is. The host is always given a PF which is a leg of
eswitch managed on the SmartNIC.
>
>Do we need a distinction based on whether the SmartNIC controls Host's
>eswitch vs just the Host in its entirety (i.e. VF switching vs bare
>metal)?
I have this described in the "PFs" section. Basically we need to have a
toggle to say "host is managing it's own nested eswitch.
>
>I find it really useful to be able to list use cases, and constraints
>first. Then go onto the design.
>
>> Note that the PF is merged with physical port representor.
>> That is due to simpler and flawless transition from legacy mode and back.
>> The devlink_ports and netdevs for physical ports are staying during
>> the transition.
>
>When users put an interface under bridge or a bond they have to move
>IP addresses etc. onto the bond. Changing mode to "switchdev" is a more
>destructive operation and there should be no expectation that
>configuration survives.
Yeah, I was saying the same thing when our arch came up with this, but
I now think it is just fine. It is drivers responsibility to do the
shift. And the entities representing the uplink port: netdevs and
devlink_port instances. They can easily stay during the transition. The
transition only applies to the eswitch and VF entities.
>
>The merging of the PF with the physical port representor is flawed.
Why?
>
>People push Qdisc offloads into devlink because of design shortcuts
>like this.
Could you please explain how it is related to "Qdisc offloads"
>
>> +-----------+
>> |phys port 2+-----------------------------------+
>> +-----------+ |
>> +-----------+ |
>> |phys port 1+---------------------------------+ |
>> +-----------+ | |
>> | |
>> +------------------------------------------------------------------+ | |
>> | devlink instance for the whole ASIC HOST A | | |
>> | | | |
>> | pci/0000:06:00.0 (devlink dev) | | |
>> | +->health reporters, params, info, sb, dpipe, | | |
>> | | resource, traps | | |
>> | | | | |
>> | +-+port_pci/0000:06:00.0/0+-----------------------+-------------|--+ |
>> | | | flavour physical pfnum 0 (phys port and pf) ^ | |
>
>Please no.
What exactly "no"?
>
>> | | | netdev enp6s0f0np1 | | |
>> | | +->health reporters, params | | |
>> | | | | | |
>> | | +->slice_pci/0000:06:00.0/0+--------------------+ | |
>> | | flavour physical | |
>> | | | |
>> | +-+port_pci/0000:06:00.0/1+-----------------------+-------------|----+
>> | | | flavour physical pfnum 1 (phys port and pf) | |
>> | | | netdev enp6s0f0np2 | |
>> | | +->health reporters, params | |
>> | | | | |
>> | | +->slice_pci/0000:06:00.0/1+--------------------+ |
>> | | flavour physical |
>> | | |
>> | +-+-+port_pci/0000:06:00.0/2+-----------+-------------------+ |
>> | | | | flavour pcipf pfnum 2 ^ | |
>> | | | | netdev enp6s0f0pf2 | | |
>> | | + +->params | | |
>> | | | | | |
>> | | +->slice_pci/0000:06:00.0/2+----------+ | |
>> | | flavour pcipf | |
>> | | | |
>> | +-+-+port_pci/0000:06:00.0/3+-----------+----------------+ | |
>> | | | | flavour pcivf pfnum 2 vfnum 0 ^ | | |
>> | | | | netdev enp6s0pf2vf0 | | | |
>> | | | +->params | | | |
>> | | | | | | |
>> | | +-+slice_pci/0000:06:00.0/3+----------+ | | |
>> | | | flavour pcivf | | |
>> | | +->rate (qos), mpgroup, mac | | |
>> | | | | |
>> | +-+-+port_pci/0000:06:00.0/4+-----------+-------------+ | | |
>> | | | | flavour pcivf pfnum 0 vfnum 0 ^ | | | |
>
>So PF 0 is both on the SmartNIC where it is physical and on the Hosts?
>Is this just error in the diagram?
I think it is error in the reading. This is the VF representation
of VF pci/0000:06:00.1, on the same host A, which is the SmartNIC host.
>
>> | | | | netdev enp6s0pf0vf0 | | | | |
>> | | | +->params | | | | |
>> | | | | | | | |
>> | | +-+slice_pci/0000:06:00.0/4+----------+ | | | |
>> | | | flavour pcivf | | | |
>> | | +->rate (qos), mpgroup, mac | | | |
>> | | | | | |
>> | +-+-+port_pci/0000:06:00.0/5+-----------+----------+ | | | |
>> | | | | flavour pcisf pfnum 0 sfnum 1 ^ | | | | |
>> | | | | netdev enp6s0pf0sf1 | | | | | |
>> | | | +->params | | | | | |
>> | | | | | | | | |
>> | | +-+slice_pci/0000:06:00.0/5+----------+ | | | | |
>> | | | flavour pcisf | | | | |
>> | | +->rate (qos), mpgroup, mac | | | | |
>> | | | | | | |
>> | +-+slice_pci/0000:06:00.0/6+--------------------+ | | | | |
>> | flavour pcivf pfnum 0 vfnum 1 | | | | | |
>> | (non-ethernet (IB, NVE) | | | | | |
>> | | | | | | |
>> +------------------------------------------------------------------+
>> | | | | |
>> | | | | |
>> | | | | |
>> +----------------------------------------------+ | | | | |
>> | devlink instance PF (other host) HOST B | | | | | |
>> | | | | | | |
>> | pci/0000:10:00.0 (devlink dev) | | | | | |
>> | +->health reporters, info | | | | | |
>> | | | | | | | |
>> | +-+port_pci/0000:10:00.0/1+---------------------------------+
>> | | flavour virtual | | | | |
>> | | netdev enp16s0f0 | | | | |
>> | +->health reporters | | | | |
>> | | | | | |
>> +----------------------------------------------+ | | | |
>> | | | |
>> +----------------------------------------------+ | | | |
>> | devlink instance VF (other host) HOST B | | | | |
>> | | | | | |
>> | pci/0000:10:00.1 (devlink dev) | | | | |
>> | +->health reporters, info | | | | |
>> | | | | | | |
>> | +-+port_pci/0000:10:00.1/1+------------------------------+
>> | | flavour virtual | | | |
>> | | netdev enp16s0f0v0 | | | |
>> | +->health reporters | | | |
>> | | | | |
>> +----------------------------------------------+ | | |
>> | | |
>> +----------------------------------------------+ | | |
>> | devlink instance VF HOST A | | | |
>> | | | | |
>> | pci/0000:06:00.1 (devlink dev) | | | |
>> | +->health reporters, info | | | |
>> | | | | | |
>> | +-+port_pci/0000:06:00.1/1+---------------------------+
>> | | flavour virtual | | |
>> | | netdev enp6s0f0v0 | | |
>> | +->health reporters | | |
>> | | | |
>> +----------------------------------------------+ | |
>> | |
>> +----------------------------------------------+ | |
>> | devlink instance SF HOST A | | |
>> | | | |
>> | pci/0000:06:00.0%sf1 (devlink dev) | | |
>> | +->health reporters, info | | |
>> | | | | |
>> | +-+port_pci/0000:06:00.0%sf1/1+--------------------+
>> | | flavour virtual | |
>> | | netdev enp6s0f0s1 | |
>> | +->health reporters | |
>> | | |
>> +----------------------------------------------+ |
>> |
>> +----------------------------------------------+ |
>> | devlink instance VF HOST A | |
>> | | |
>> | pci/0000:06:00.2 (devlink dev)+----------------+
>> | +->health reporters, info |
>> | |
>> +----------------------------------------------+
>>
>>
>>
>>
>> ==================================================================
>> || ||
>> || what needs to be implemented ||
>> || ||
>> ==================================================================
>>
>> 1) physical port "pfnum". When PF and physical port representor
>> are merged, the instance of devlink_port representing the physical port
>> and PF needs to have "pfnum" attribute to be in sync
>> with other PF port representors.
>
>See above.
>
>> 2) per-port health reporters are not implemented yet.
>
>Which health reports are visible on a SmartNIC port?
I think there is usecase for SmartNIC uplink/pf port health reporters.
Those are the ones which we have for TX/RX queues on devlink instance
now (that was a mistake).
>
>The Host ones or the SmartNIC ones?
In the host, I think there is a usecase for VF/SF devlink_port health
reporters - also for TX/RX queues.
>
>I think queue reporters should be per-queue, see below.
Depends. There are reporters, like "fw" that are per-asic.
>
>> 3) devlink_port instance in PF/VF/SF flavour "virtual". In PF/VF/SF devlink
>> instance (in VM for example), there would make sense to have devlink_port
>> instance. At least to carry link to netdevice name (otherwise we have
>> no easy way to find out devlink instance and netdevice belong to each other).
>> I was thinking about flavour name, we have to distinguish from eswitch
>> devlink port flavours "pcipf, pcivf, pcisf".
>
>Virtual is the flavor for the VF port, IIUC, so what's left to name?
>Do you mean pick a phys_port_name format?
No. "virtual" is devlink_port flavour in the host in the VF devlink
instance. See port_pci/0000:10:00.0/1 above for example.
>
>> This was recently implemented by Parav:
>> commit 0a303214f8cb8e2043a03f7b727dba620e07e68d
>> Merge: c04d102ba56e 162add8cbae4
>> Author: David S. Miller <davem@...emloft.net>
>> Date: Tue Mar 3 15:40:40 2020 -0800
>>
>> Merge branch 'devlink-virtual-port'
>>
>> What is missing is the "virtual" flavour for nested PF.
>>
>> 4) slice is not implemented yet. This is the original "vdev/subdev" concept.
>> See below section "Slice user cmdline API draft".
>>
>> 5) SFs are not implemented.
>> See below section "SF (subfunction) user cmdline API draft".
>>
>> 6) rate for slice are not implemented yet.
>> See below section "Slice rate user cmdline API draft".
>>
>> 7) mpgroup for slice is not implemented yet.
>> See below section "Slice mpgroup user cmdline API draft".
>>
>> 8) VF manual creation using devlink is not implemented yet.
>> See below section "VF manual creation and activation user cmdline API draft".
>>
>> 9) PF aliasing. One devlink instance and multiple PFs sharing it as they have one
>> merged e-switch.
>>
>>
>>
>> ==================================================================
>> || ||
>> || Issues/open questions ||
>> || ||
>> ==================================================================
>>
>> 1) "pfnum" has to be per-asic(/devlink instance), not per-host.
>> That means that in smartNIC scenario, we cannot have "pfnum 0"
>> for smartNIC and "pfnum 0" for host as well.
>
>Right, exactly, NFP already does that.
>
>> 2) Q: for TX, RX queues reporters, should it be bound to devlink_port?
>> For which flavours this might make sense?
>> Most probably for flavours "physical"/"virtual".
>> How about the reporters in VF/SF?
>
>I think with the work Magnus is doing we should have queues as first
Can you point me to the "work"?
>class citizens to be able to allocate them to ports.
>
>Would this mean we can hang reporters off queues?
Yes, If we have a "queue object", the per-queue reporter would make sense.
>
>> 3) How the management of nested switch is handled. The PFs created dynamically
>> or the ones in hosts in smartnic scenario may themselves be each a manager
>> of nested e-switch. How to toggle this capability?
>> During creation by a cmdline option?
>> During lifetime in case the PF does not have any childs (VFs/SFs)?
>
>Maybe the grouping of functions into devlink instances would help?
>SmartNIC could control if the host can perform switching between
>functions by either putting them in the same Host side devlink
>instance or not.
I'm not sure I follow. There is a number of PFs created "on probe".
Those are fixed and driver knows where to put them.
The comment was about possible "dynamic PF" created by user in the same
was he creates SF, by devlink cmdline.
Now the PF itself can have a "nested eswitch" to manage. The "parent
eswitch" where the PF was created would only see one leg to the "nested
eswitch".
This "nested eswitch management" might or might not be required. Depends
on a usecare. The question was, how to configure that I as a user
want this or not.
>
>> ==================================================================
>> || ||
>> || Slice user cmdline API draft ||
>> || ||
>> ==================================================================
>>
>> Note that some of the "devlink port" attributes may be forgotten or misordered.
>>
>> Slices and ports are created together by device driver. The driver defines
>> the relationships during creation.
>>
>>
>> $ devlink port show
>> pci/0000:06:00.0/0: flavour physical pfnum 0 type eth netdev enp6s0f0np1
>> pci/0000:06:00.0/1: flavour physical pfnum 1 type eth netdev enp6s0f0np2
>> pci/0000:06:00.0/2: flavour pcivf pfnum 0 vfnum 0 type eth netdev enp6s0pf0vf0 slice 0
>> pci/0000:06:00.0/3: flavour pcivf pfnum 0 vfnum 1 type eth netdev enp6s0pf0vf1 slice 1
>> pci/0000:06:00.0/4: flavour pcivf pfnum 1 vfnum 0 type eth netdev enp6s0pf1vf0 slice 2
>> pci/0000:06:00.0/5: flavour pcivf pfnum 1 vfnum 1 type eth netdev enp6s0pf1vf1 slice 3
>>
>> $ devlink slice show
>> pci/0000:06:00.0/0: flavour physical pfnum 0 port 0 state active
>> pci/0000:06:00.0/1: flavour physical pfnum 1 port 1 state active
>> pci/0000:06:00.0/2: flavour pcivf pfnum 0 vfnum 0 port 2 hw_addr 10:22:33:44:55:66 state active
>> pci/0000:06:00.0/3: flavour pcivf pfnum 0 vfnum 1 port 3 hw_addr 10:22:33:44:55:77 state active
>> pci/0000:06:00.0/4: flavour pcivf pfnum 1 vfnum 0 port 4 hw_addr 10:22:33:44:55:88 state active
>> pci/0000:06:00.0/5: flavour pcivf pfnum 1 vfnum 1 port 5 hw_addr 10:22:33:44:55:99 state active
>> pci/0000:06:00.0/6: flavour pcivf pfnum 1 vfnum 2
>>
>> In these 2 outputs you can see the relationships. Attributes "slice" and "port"
>> indicate the slice-port pairs.
>>
>> Also, there is a fixed "state" attribute with value "active". This is by
>> default as the VFs are always created active. In future, it is planned
>> to implement manual VF creation and activation, similar to what is below
>> described for SFs.
>>
>> Note that for non-ethernet slice (the last one) does not have any
>> related port port. It can be for example NVE or IB. But since
>> the "hw_addr" attribute is also omitted, it isn't IB.
>>
>>
>> Now set a different MAC address for VF1 on PF0:
>> $ devlink slice set pci/0000:06:00.0/3 hw_addr aa:bb:cc:dd:ee:ff
>>
>> $ devlink slice show
>> pci/0000:06:00.0/0: flavour physical pfnum 0 port 0 state active
>> pci/0000:06:00.0/1: flavour physical pfnum 1 port 1 state active
>> pci/0000:06:00.0/2: flavour pcivf pfnum 0 vfnum 0 port 2 hw_addr 10:22:33:44:55:66 state active
>> pci/0000:06:00.0/3: flavour pcivf pfnum 0 vfnum 1 port 3 hw_addr aa:bb:cc:dd:ee:ff state active
>> pci/0000:06:00.0/4: flavour pcivf pfnum 1 vfnum 0 port 4 hw_addr 10:22:33:44:55:88 state active
>> pci/0000:06:00.0/5: flavour pcivf pfnum 1 vfnum 1 port 5 hw_addr 10:22:33:44:55:99 state active
>> pci/0000:06:00.0/6: flavour pcivf pfnum 1 vfnum 2
>
>What are slices?
Slice is basically a piece of ASIC. pf/vf/sf. They serve for
configuration of the "other side of the wire". Like the mac. Hypervizor
admin can use the slite to set the mac address of a VF which is in the
virtual machine. Basically this should be a replacement of "ip vf"
command.
>
>> ==================================================================
>> || ||
>> || SF (subfunction) user cmdline API draft ||
>> || ||
>> ==================================================================
>>
>> Note that some of the "devlink port" attributes may be forgotten or misordered.
>>
>> Note that some of the "devlink slice" attributes in show commands
>> are omitted on purpose.
>>
>> $ devlink port show
>> pci/0000:06:00.0/0: flavour physical pfnum 0 type eth netdev enp6s0f0np1
>> pci/0000:06:00.0/1: flavour physical pfnum 1 type eth netdev enp6s0f0np2
>> pci/0000:06:00.0/2: flavour pcivf pfnum 0 vfnum 0 type eth netdev enp6s0pf0vf0 slice 2
>>
>> $ devlink slice show
>> pci/0000:06:00.0/0: flavour physical pfnum 0 port 0 state active
>> pci/0000:06:00.0/1: flavour physical pfnum 1 port 1 state active
>> pci/0000:06:00.0/2: flavour pcivf pfnum 0 vfnum 0 port 2 hw_addr 10:22:33:44:55:66
>>
>> There is one VF on the NIC.
>>
>>
>> Now create subfunction of SF0 on PF1, index of the slice is going to be 100
>> and hw_address aa:bb:cc:aa:bb:cc.
>>
>> $ devlink slice add pci/0000.06.00.0/100 flavour pcisf pfnum 1 sfnum 10 hw_addr aa:bb:cc:aa:bb:cc
>
>Why is the SF number specified by the user rather than allocated?
Because it is snown in representor netdevice name. And you need to have
it predetermined: enp6s0pf1sf10
>
>> The devlink kernel code calls down to device driver (devlink op) and asks
>> it to create a slice with particular attributes. Driver then instatiates
>> the slice and port in the same way it is done for VF:
>>
>> $ devlink port show
>> pci/0000:06:00.0/0: flavour physical pfnum 0 type eth netdev enp6s0f0np1
>> pci/0000:06:00.0/1: flavour physical pfnum 1 type eth netdev enp6s0f0np2
>> pci/0000:06:00.0/2: flavour pcivf pfnum 0 vfnum 0 type eth netdev enp6s0pf0vf0 slice 2
>> pci/0000:06:00.0/3: flavour pcisf pfnum 1 sfnum 10 type eth netdev enp6s0pf1sf10 slice 100
>>
>> $ devlink slice show
>> pci/0000:06:00.0/0: flavour physical pfnum 0 port 0 state active
>> pci/0000:06:00.0/1: flavour physical pfnum 1 port 1 state active
>> pci/0000:06:00.0/2: flavour pcivf pfnum 0 vfnum 0 port 2 hw_addr 10:22:33:44:55:66
>> pci/0000:06:00.0/100: flavour pcisf pfnum 1 sfnum 10 port 3 hw_addr aa:bb:cc:aa:bb:cc state inactive
>>
>> Note that the SF slice is created but not active. That means the
>> entities are created on devlink side, the e-switch port representor
>> is created, but the SF device itself it not yet out there (same host
>> or different, depends on where the parent PF is - in this case the same host).
>> User might use e-switch port representor enp6s0pf1sf10 to do settings,
>> putting it into bridge, adding TC rules, etc.
>> It's like the cable is unplugged on the other side.
>
>If it's just "cable unplugged" can't we just use the fact the
>representor is down to indicate no traffic can flow?
It is not "cable unplugged". This "state inactive/action" is admin
state. You as a eswitch admin say, "I'm done with configuring a slice
(MAC) and a representor (bridge, TC, etc) for this particular SF and
I want the HOST to instantiate the SF instance (with the configured
MAC).
>
>> Now we activate (deploy) the SF:
>> $ devlink slice set pci/0000:06:00.0/100 state active
>>
>> $ devlink slice show
>> pci/0000:06:00.0/0: flavour physical pfnum 0 port 0 state active
>> pci/0000:06:00.0/1: flavour physical pfnum 1 port 1 state active
>> pci/0000:06:00.0/2: flavour pcivf pfnum 0 vfnum 0 port 2 hw_addr 10:22:33:44:55:66
>> pci/0000:06:00.0/100: flavour pcisf pfnum 1 sfnum 10 port 3 hw_addr aa:bb:cc:aa:bb:cc state active
>>
>> Upon the activation, the device driver asks the device to instantiate
>> the actual SF device on particular PF. Does not matter if that is
>> on the same host or not.
>>
>> On the other side, the PF driver instance gets the event from device
>> that particular SF was activated. It's the cue to put the device on bus
>> probe it and instantiate netdev and devlink instances for it.
>
>Seems backwards. It's the PF that wants the new function, why can't it
>just create it and either get an error from the other side or never get
>link up?
We discussed that many times internally. I think it makes sense that
the SF is created by the same entity that manages the related eswitch
SF-representor. In other words, the "devlink slice" and related "devlink
port" object are under the same devlink instance.
If the PF in host manages nested switch, it can create the SF inside and
manages the neste eswitch SF-representor as you describe.
It is a matter of "nested eswitch manager on/off" configuration.
I think this is clean model and it is known who has what
responsibilities.
>
>> For every SF a device is created on wirtbus with an ID assigned by the
>> virtbus code. For example:
>> /sys/bus/virtbus/devices/mlx5_sf.1
>>
>> $ cat /sys/bus/virtbus/devices/mlx5_sf.1/sfnum
>> 10
>>
>> /sys/bus/virtbus/devices/mlx5_sf.1 is a symlink to:
>> ../../../devices/pci0000:00/0000:00:03.0/0000:06:00.0/mlx5_sf.1
>>
>> New devlink instance is named using alias:
>> $ devlink dev show
>> pci/0000:06:00.0%sf10
>>
>> $ devlink port show
>> pci/0000:06:00.0%sf10/0: flavour virtual type eth netdev netdev enp6s0f0s10
>>
>> You see that the udev used the sysfs files and symlink to assemble netdev name.
>>
>> Note that this kind of aliasing is not implemented. Needs to be done in
>> devlink code in kernel. During SF devlink instance creation, there should
>> be passed parent PF device pointer and sfnum from which the alias dev_name
>> is assembled. This ensures persistent naming consistent in both smartnic
>> and host usecase.
>>
>> If the user on smartnic or host does not want the virtbus device to get
>> probed automatically (for any reason), he can do it by:
>>
>> $ echo "0" > /sys/bus/virtbus/drivers_autoprobe
>>
>> This is enabled by default.
>>
>>
>> User can deactivate the slice by:
>>
>> $ devlink slice set pci/0000:06:00.0/100 state inactive
>>
>> This eventually leads to event delivered to PF driver, which is a
>> cue to remove the SF device from virtbus and remove all related devlink
>> and netdev instances.
>>
>> The slice may be activated again.
>>
>> Now on the teardown process, user might either remove the SF slice
>> right away, without deactivation. However, it is possible to remove
>> deactivated SF too. To remove the SF, user should do:
>>
>> $ devlink slice del pci/0000:06:00.0/100
>>
>> $ devlink port show
>> pci/0000:06:00.0/0: flavour physical pfnum 0 type eth netdev enp6s0f0np1
>> pci/0000:06:00.0/1: flavour physical pfnum 1 type eth netdev enp6s0f0np2
>> pci/0000:06:00.0/2: flavour pcivf pfnum 0 vfnum 0 type eth netdev enp6s0pf0vf0 slice 2
>>
>> $ devlink slice show
>> pci/0000:06:00.0/0: flavour physical pfnum 0 port 0 state active
>> pci/0000:06:00.0/1: flavour physical pfnum 1 port 1 state active
>> pci/0000:06:00.0/2: flavour pcivf pfnum 0 vfnum 0 port 2 hw_addr 10:22:33:44:55:66
>
>The destruction also seems wrong way around. Could you explain why it
>makes sense to create from SmartNIC side?
See above.
>
>> ==================================================================
>> || ||
>> || VF manual creation and activation user cmdline API draft ||
>> || ||
>> ==================================================================
>>
>> To enter manual mode, the user has to turn off VF dummies creation:
>> $ devlink dev set pci/0000:06:00.0 vf_dummies disabled
>> $ devlink dev show
>> pci/0000:06:00.0: vf_dummies disabled
>>
>> It is "enabled" by default in order not to break existing users.
>>
>> By setting the "vf_dummies" attribute to "disabled", the driver
>> removes all dummy VFs. Only physical ports are present:
>>
>> $ devlink port show
>> pci/0000:06:00.0/0: flavour physical pfnum 0 type eth netdev enp6s0f0np1
>> pci/0000:06:00.0/1: flavour physical pfnum 1 type eth netdev enp6s0f0np2
>>
>> Then the user is able to create them in a similar way as SFs:
>>
>> $ devlink slice add pci/0000:06:00.0/99 flavour pcivf pfnum 1 vfnum 8 hw_addr aa:bb:cc:aa:bb:cc
>>
>> The devlink kernel code calls down to device driver (devlink op) and asks
>> it to create a slice with particular attributes. Driver then instatiates
>> the slice and port:
>>
>> $ devlink port show
>> pci/0000:06:00.0/0: flavour physical pfnum 0 type eth netdev enp6s0f0np1
>> pci/0000:06:00.0/1: flavour physical pfnum 1 type eth netdev enp6s0f0np2
>> pci/0000:06:00.0/2: flavour pcivf pfnum 1 vfnum 8 type eth netdev enp6s0pf1vf0 slice 99
>>
>> $ devlink slice show
>> pci/0000:06:00.0/0: flavour physical pfnum 0 port 0 state active
>> pci/0000:06:00.0/1: flavour physical pfnum 1 port 1 state active
>> pci/0000:06:00.0/99: flavour pcivf pfnum 1 vfnum 8 port 2 hw_addr aa:bb:cc:aa:bb:cc state inactive
>>
>> Now we activate (deploy) the VF:
>> $ devlink slice set pci/0000:06:00.0/99 state active
>>
>> $ devlink slice show
>> pci/0000:06:00.0/99: flavour pcivf pfnum 1 vfnum 8 port 2 hw_addr aa:bb:cc:aa:bb:cc state active
>>
>> ==================================================================
>> || ||
>> || PFs ||
>> || ||
>> ==================================================================
>>
>> There are 2 flavours of PFs:
>> 1) Parent PF. That is coupled with uplink port. The slice flavour is
>> therefore "physical", to be in sync of the flavour of the uplink port.
>> In case this Parent PF is actually a leg of upstream embedded switch,
>> the slice flavour is "virtual" (same as the port flavour).
>>
>> $ devlink port show
>> pci/0000:06:00.0/0: flavour physical pfnum 0 type eth netdev enp6s0f0np1 slice 0
>>
>> $ devlink slice show
>> pci/0000:06:00.0/0: flavour physical pfnum 0 port 0 state active
>>
>> This slice is shown in both "switchdev" and "legacy" modes.
>>
>> If there is another parent PF, say "0000:06:00.1", that share the
>> same embedded switch, the aliasing is established for devlink handles.
>>
>> The user can use devlink handles:
>> pci/0000:06:00.0
>> pci/0000:06:00.1
>> as equivalents, pointing to the same devlink instance.
>>
>> Parent PFs are the ones that may be in control of managing
>> embedded switch, on any hierarchy level.
>>
>> 2) Child PF. This is a leg of a PF put to the parent PF. It is
>> represented by a slice, and a port (with a netdevice):
>>
>> $ devlink port show
>> pci/0000:06:00.0/0: flavour physical pfnum 0 type eth netdev enp6s0f0np1 slice 0
>> pci/0000:06:00.0/1: flavour pcipf pfnum 2 type eth netdev enp6s0f0pf2 slice 20
>>
>> $ devlink slice show
>> pci/0000:06:00.0/0: flavour physical pfnum 0 port 0 state active
>> pci/0000:06:00.0/20: flavour pcipf pfnum 1 port 1 hw_addr aa:bb:cc:aa:bb:87 state active <<<<<<<<<<
>>
>> This is a typical smartnic scenario. You would see this list on
>> the smartnic CPU. The slice pci/0000:06:00.0/20 is a leg to
>> one of the hosts. If you send packets to enp6s0f0pf2, they will
>> go to he host.
>>
>> Note that inside the host, the PF is represented again as "Parent PF"
>> and may be used to configure nested embedded switch.
>
>This parent/child PF I don't understand. Does it stem from some HW
>limitations you have?
No limitation. It's just a name for 2 roles. I didn't know how else to
name it for the documentation purposes. Perhaps you can help me.
The child can simply manage a "nested eswich". The "parent eswitch"
would see one leg (pf representor) one way or another. Only in case the
"nested eswitch" is there, the child would manage it - have separate
representors for vfs/sfs under its devlink instance.
>
>> ==================================================================
>> || ||
>> || Slice operational state extension ||
>> || ||
>> ==================================================================
>>
>> In addition to the "state" attribute that serves for the purpose
>> of setting the "admin state", there is "opstate" attribute added to
>> reflect the operational state of the slice:
>>
>>
>> opstate description
>> ----------- ------------
>> 1. attached State when slice device is bound to the host
>> driver. When the slice device is unbound from the
>> host driver, slice device exits this state and
>> enters detaching state.
>>
>> 2. detaching State when host is notified to deactivate the
>> slice device and slice device may be undergoing
>> detachment from host driver. When slice device is
>> fully detached from the host driver, slice exits
>> this state and enters detached state.
>>
>> 3. detached State when driver is fully unbound, it enters
>> into detached state.
>>
>> slice state machine:
>> --------------------
>> slice state set inactive
>> ----<------------------<---
>> | or slice delete |
>> | |
>> __________ ____|_______ ____|_______
>> | | slice add | |slice state | |
>> | |-------->---| |------>-----| |
>> | invalid | | inactive | set active | active |
>> | | slice del | | | |
>> |__________|--<---------|____________| |____________|
>>
>> slice device operational state machine:
>> ---------------------------------------
>> __________ ____________ ___________
>> | | slice state | |driver bus | |
>> | invalid |-------->-----| detached |------>-----| attached |
>> | | set active | | probe() | |
>> |__________| |____________| |___________|
>> | |
>> ^ slice set
>> | set inactive
>> successful detach |
>> or pf reset |
>> ____|_______ |
>> | | driver bus |
>> -----------| detaching |---<-------------
>> | | | remove()
>> ^ |____________|
>> | timeout |
>> --<---------------
>>
>>
>>
>> ==================================================================
>> || ||
>> || Slice rate user cmdline API draft ||
>> || ||
>> ==================================================================
>>
>> Note that some of the "devlink slice" attributes in show commands
>> are omitted on purpose.
>>
>>
>> $ devlink slice show
>> pci/0000:06:00.0/0: flavour physical pfnum
>> pci/0000:06:00.0/1: flavour pcivf pfnum 0 vfnum 1
>> pci/0000:06:00.0/2: flavour pcivf pfnum 0 vfnum 0
>> pci/0000:06:00.0/3: flavour pcivf pfnum 0 vfnum 1
>> pci/0000:06:00.0/4: flavour pcisf pfnum 0 sfnum 1
>>
>> Slice object is extended with new rate object.
>>
>>
>> $ devlink slice rate
>> pci/0000:06:00.0/1: type leaf
>> pci/0000:06:00.0/2: type leaf
>> pci/0000:06:00.0/3: type leaf
>> pci/0000:06:00.0/4: type leaf
>>
>> This shows the leafs created by default alongside with slice objects. No min or
>> max tx rates were set, so their values are omitted.
>>
>>
>> Now create new node rate object:
>>
>> $ devlink slice rate add pci/0000:06:00.0/somerategroup
>>
>> $ devlink slice rate
>> pci/0000:06:00.0/1: type leaf
>> pci/0000:06:00.0/2: type leaf
>> pci/0000:06:00.0/3: type leaf
>> pci/0000:06:00.0/4: type leaf
>> pci/0000:06:00.0/somerategroup: type node
>>
>> New node rate object was created - the last line.
>>
>>
>> Now create another new node object was created, this time with some attributes:
>>
>> $ devlink slice rate add pci/0000:06:00.0/secondrategroup min_tx_rate 20 max_tx_rate 1000
>>
>> $ devlink slice rate
>> pci/0000:06:00.0/1: type leaf
>> pci/0000:06:00.0/2: type leaf
>> pci/0000:06:00.0/3: type leaf
>> pci/0000:06:00.0/4: type leaf
>> pci/0000:06:00.0/somerategroup: type node
>> pci/0000:06:00.0/secondrategroup: type node min_tx_rate 20 max_tx_rate 1000
>>
>> Another new node object was created - the last line. The object has min and max
>> tx rates set, so they are displayed after the object type.
>>
>>
>> Now set node named somerategroup min/max rate using rate object:
>>
>> $ devlink slice rate set pci/0000:06:00.0/somerategroup min_tx_rate 50 max_tx_rate 5000
>>
>> $ devlink slice rate
>> pci/0000:06:00.0/1: type leaf
>> pci/0000:06:00.0/2: type leaf
>> pci/0000:06:00.0/3: type leaf
>> pci/0000:06:00.0/4: type leaf
>> pci/0000:06:00.0/somerategroup: type node min_tx_rate 50 max_tx_rate 5000
>> pci/0000:06:00.0/secondrategroup: type node min_tx_rate 20 max_tx_rate 1000
>>
>>
>> Now set leaf slice rate using rate object:
>>
>> $ devlink slice rate set pci/0000:06:00.0/2 min_tx_rate 10 max_tx_rate 10000
>>
>> $ devlink slice rate
>> pci/0000:06:00.0/1: type leaf
>> pci/0000:06:00.0/2: type leaf min_tx_rate 10 max_tx_rate 10000
>> pci/0000:06:00.0/3: type leaf
>> pci/0000:06:00.0/4: type leaf
>> pci/0000:06:00.0/somerategroup: type node min_tx_rate 50 max_tx_rate 5000
>> pci/0000:06:00.0/secondrategroup: type node min_tx_rate 20 max_tx_rate 1000
>>
>>
>> Now set leaf slice with index 2 parent node using rate object:
>>
>> $ devlink slice rate set pci/0000:06:00.0/2 parent somerategroup
>>
>> $ devlink slice rate
>> pci/0000:06:00.0/1: type leaf
>> pci/0000:06:00.0/2: type leaf min_tx_rate 10 max_tx_rate 10000 parent somerategroup
>> pci/0000:06:00.0/3: type leaf
>> pci/0000:06:00.0/4: type leaf
>> pci/0000:06:00.0/somerategroup: type node min_tx_rate 50 max_tx_rate 5000
>> pci/0000:06:00.0/secondrategroup: type node min_tx_rate 20 max_tx_rate 1000
>>
>>
>> Now set leaf slice with index 1 parent node using rate object:
>>
>> $ devlink slice rate set pci/0000:06:00.0/1 parent somerategroup
>>
>> $ devlink slice rate
>> pci/0000:06:00.0/1: type leaf parent somerategroup
>> pci/0000:06:00.0/2: type leaf min_tx_rate 10 max_tx_rate 10000 parent somerategroup
>> pci/0000:06:00.0/3: type leaf
>> pci/0000:06:00.0/4: type leaf
>> pci/0000:06:00.0/somerategroup: type node min_tx_rate 50 max_tx_rate 5000
>> pci/0000:06:00.0/secondrategroup: type node min_tx_rate 20 max_tx_rate 1000
>>
>>
>> Now unset leaf slice with index 1 parent node using rate object:
>>
>> $ devlink slice rate set pci/0000:06:00.0/1 noparent
>>
>> $ devlink slice rate
>> pci/0000:06:00.0/1: type leaf
>> pci/0000:06:00.0/2: type leaf min_tx_rate 10 max_tx_rate 10000 parent somerategroup
>> pci/0000:06:00.0/3: type leaf
>> pci/0000:06:00.0/4: type leaf
>> pci/0000:06:00.0/somerategroup: type node min_tx_rate 50 max_tx_rate 5000
>> pci/0000:06:00.0/secondrategroup: type node min_tx_rate 20 max_tx_rate 1000
>>
>>
>> Now delete node object:
>>
>> $ devlink slice rate del pci/0000:06:00.0/somerategroup
>>
>> $ devlink slice rate
>> pci/0000:06:00.0/1: type leaf
>> pci/0000:06:00.0/2: type leaf
>> pci/0000:06:00.0/3: type leaf
>> pci/0000:06:00.0/4: type leaf
>>
>> Rate node object was removed and its only child pci/0000:06:00.0/2 automatically
>> detached.
>
>Tomorrow we will support CoDel, ECN or any other queuing construct.
>How many APIs do we want to have to configure the same thing? :/
Rigth, I don't see other way. Please help me to figure out this
differently. Note this is for configuring HW limits on the TX side of VF.
We have only devlink_port and related netdev as representor of the VF
eswitch port. We cannot use this netdev to configure qdisc on RX.
>
>> ==================================================================
>> || ||
>> || Slice ib groupping user cmdline API draft ||
>> || ||
>> ==================================================================
>>
>> Note that some of the "devlink slice" attributes in show commands
>> are omitted on purpose.
>>
>> The reason for this IB groupping is that the VFs inside virtual machine
>> get information (via device) about which two of more VF devices should
>> be combined together to form one multi-port IB device. In the virtual
>> machine it is driver's responsibility to setup the combined
>> multi-port IB devices.
>>
>> Consider following setup:
>>
>> $ devlink slice show
>> pci/0000:06:00.0/0: flavour physical pfnum 0
>> pci/0000:06:00.0/1: flavour physical pfnum 1
>> pci/0000:06:00.0/2: flavour pcivf pfnum 0 vfnum 0
>> pci/0000:06:00.0/3: flavour pcivf pfnum 0 vfnum 1
>> pci/0000:06:00.0/4: flavour pcivf pfnum 1 vfnum 0
>> pci/0000:06:00.0/5: flavour pcivf pfnum 1 vfnum 1
>>
>>
>> Each VF/SF slice has IB leaf object related to it:
>>
>> $ devlink slice ib
>> pci/0000:06:00.0/2: type leaf
>> pci/0000:06:00.0/3: type leaf
>> pci/0000:06:00.0/4: type leaf
>> pci/0000:06:00.0/5: type leaf
>>
>> You see that by default, each slice is marked as a leaf.
>> There is no groupping set.
>>
>>
>> User may add a ib group node by issuing following command:
>>
>> $ devlink slice ib add pci/0000:06:00.0/somempgroup1
>>
>> $ devlink slice ib
>> pci/0000:06:00.0/2: type leaf
>> pci/0000:06:00.0/3: type leaf
>> pci/0000:06:00.0/4: type leaf
>> pci/0000:06:00.0/5: type leaf
>> pci/0000:06:00.0/someibgroup1: type node
>>
>> New node ib node object was created - the last line.
>>
>>
>> Now set leaf slice with index 2 parent node using ib object:
>>
>> $ devlink slice ib set pci/0000:06:00.0/2 parent someibgroup1
>>
>> $ devlink slice ib
>> pci/0000:06:00.0/2: type leaf parent someibgroup1
>> pci/0000:06:00.0/3: type leaf
>> pci/0000:06:00.0/4: type leaf
>> pci/0000:06:00.0/5: type leaf
>> pci/0000:06:00.0/someibgroup1: type node
>>
>>
>> Now set leaf slice with index 5 parent node using ib object:
>>
>> $ devlink slice ib set pci/0000:06:00.0/5 parent someibgroup1
>>
>> $ devlink slice ib
>> pci/0000:06:00.0/2: type leaf parent someibgroup1
>> pci/0000:06:00.0/3: type leaf
>> pci/0000:06:00.0/4: type leaf
>> pci/0000:06:00.0/5: type leaf parent someibgroup1
>> pci/0000:06:00.0/someibgroup1: type node
>>
>> Now you can see there are 2 leaf devices configured to have one parent.
>>
>>
>> To remove the parent link, user should issue following command:
>>
>> $ devlink slice ib set pci/0000:06:00.0/5 noparent
>>
>> $ devlink slice ib
>> pci/0000:06:00.0/2: type leaf parent someibgroup1
>> pci/0000:06:00.0/3: type leaf
>> pci/0000:06:00.0/4: type leaf
>> pci/0000:06:00.0/5: type leaf
>> pci/0000:06:00.0/someibgroup1: type node
>>
>>
>> Now delete node object:
>>
>> $ devlink slice ib del pci/0000:06:00.0/somempgroup1
>> $ devlink slice ib
>> pci/0000:06:00.0/2: type leaf
>> pci/0000:06:00.0/3: type leaf
>> pci/0000:06:00.0/4: type leaf
>> pci/0000:06:00.0/5: type leaf
>>
>> Node object was removed and its only child pci/0000:06:00.0/2 automatically
>> detached.
>>
>>
>> It is not possible to delete leafs:
>>
>> $ devlink slice ib del pci/0000:06:00.0/2
>> devlink answers: Operation not supported
>>
>>
>>
>> ==================================================================
>> || ||
>> || Dynamic PFs user cmdline API draft ||
>> || ||
>> ==================================================================
>>
>> User might want to create another PF, similar as VF.
>> TODO
>
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