Subject: Re: [Patch v4 03/12] net: mana: Handle vport sharing between devices

From: Jason Gunthorpe <[email-masked]>
Date: Wed, 20 Jul 2022 20:42:09 -0300

On Tue, Jul 12, 2022 at 06:48:09PM +0000, Long Li wrote:
> > > @@ -563,9 +581,19 @@ static int mana_cfg_vport(struct
> > > mana_port_context *apc, u32 protection_dom_id,
> > >
> > >  	apc->tx_shortform_allowed = resp.short_form_allowed;
> > >  	apc->tx_vp_offset = resp.tx_vport_offset;
> > > +
> > > +	netdev_info(apc->ndev, "Configured vPort %llu PD %u DB %u\n",
> > > +		    apc->port_handle, protection_dom_id, doorbell_pg_id);
> > Should this be netdev_dbg()?
> > The log buffer can be flooded if there are many vPorts per VF PCI device and
> > there are a lot of VFs.
> 
> The reason netdev_info () is used is that this message is important
> for troubleshooting initial setup issues with Ethernet driver. We
> rely on user to get this configured right to share the same hardware
> port between Ethernet and RDMA driver. As far as I know, there is no
> easy way for a driver to "take over" an exclusive hardware resource
> from another driver.

This seems like a really strange statement.

Exactly how does all of this work?

Jason