Tue, Feb 21, 2023 at 12:54:25AM CET, shannon.nelson@amd.com wrote:

On 2/20/23 12:22 AM, Jiri Pirko wrote:

quoted

Fri, Feb 17, 2023 at 11:55:45PM CET, shannon.nelson@amd.com wrote:

quoted

Add a new device generic parameter to enable/disable support
for live migration in the devlink device.  This is intended
primarily for a core device that supports other ports/VFs/SFs.
Those dependent ports may need their own migratable parameter
for individual enable/disable control.

Examples:
  $ devlink dev param set pci/0000:07:00.0 name enable_migration value true cmode runtime
  $ devlink dev param show pci/0000:07:00.0 name enable_migration
  pci/0000:07:00.0:
    name enable_migration type generic
      values:
        cmode runtime value true

Signed-off-by: Shannon Nelson <redacted>

Could you please elaborate why exactly is this needed?

 From my perspective, the migration capability is something that
is related to the actual function (VF/SF).

When instantiating/configuring SF/VF, the admin ask for the particular
function to support live migration. We have port function caps now,
which is exactly where this makes sense.

See DEVLINK_PORT_FN_CAP_MIGRATABLE.

Hi Jiri,

Thanks for your questions.  My apologies for not getting your name into the
To: list – a late Friday afternoon miss.

This enable_migration flag is intended to be similar to the enable_vnet,
enable_rdma, and similar existing parameters that are used by other core
devices.

Our pds_core device can be used to support several features (currently VFio
and vDPA), and this gives the user a way to control how many of the features
are made available in any particular configuration.  This is to be enabled to
turn on support for our pds_vfio client devices as a whole, not individually
port-by-port.  I understand FN_CAP_MIGRATABLE to be applied to an individual
devlink port, which could be used in conjunction with this once the general
feature is enable in pds_core.

Okay, that sounds legit. Could yout please extend the patch description
with this? Thanks!

Thanks,
sln