RE: [PATCH v4 05/23] ice: Add devlink params support

Subject: Re: [PATCH v4 05/23] ice: Add devlink params support

On Tue, Apr 06, 2021 at 04:01:07PM -0500, Shiraz Saleem wrote:

quoted

Add a new generic runtime devlink parameter 'rdma_protocol'
and use it in ice PCI driver. Configuration changes result in
unplugging the auxiliary RDMA device and re-plugging it with updated
values for irdma auxiiary driver to consume at
drv.probe()

Signed-off-by: Shiraz Saleem <redacted>
 .../networking/devlink/devlink-params.rst          |  6 ++
 Documentation/networking/devlink/ice.rst           | 13 +++
 drivers/net/ethernet/intel/ice/ice_devlink.c       | 92 +++++++++++++++++++++-
 drivers/net/ethernet/intel/ice/ice_devlink.h       |  5 ++
 drivers/net/ethernet/intel/ice/ice_main.c          |  2 +
 include/net/devlink.h                              |  4 +
 net/core/devlink.c                                 |  5 ++
 7 files changed, 125 insertions(+), 2 deletions(-)

diff --git a/Documentation/networking/devlink/devlink-params.rst

b/Documentation/networking/devlink/devlink-params.rst
index 54c9f10..0b454c3 100644

+++ b/Documentation/networking/devlink/devlink-params.rst

@@ -114,3 +114,9 @@ own name.
        will NACK any attempt of other host to reset the device. This parameter
        is useful for setups where a device is shared by different hosts, such
        as multi-host setup.
+   * - ``rdma_protocol``
+     - string
+     - Selects the RDMA protocol selected for multi-protocol devices.
+        - ``iwarp`` iWARP
+	- ``roce`` RoCE
+	- ``ib`` Infiniband

I'm still not sure this belongs in devlink.

I believe you suggested we use devlink for protocol switch.

What about devices that support roce and iwarp concurrently?

There is nothing at the protocol level that precludes this - doesn't this device allow
it?

Nope. This device doesn’t support both protocols concurrently on same PCI function.

Maybe then it makes sense to move this protocol switch as driver specific devlink?

I know Parav is looking at the general problem of how to customize what aux
devices are created, that may be a better fit for this.

Can you remove the devlink parts to make progress?

It is important since otherwise the customer will have no way to use RoCEv2 on this device.

Shiraz