Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Wed, 20 Jul 2022 20:42:09 -0300
From:   Jason Gunthorpe <jgg@ziepe.ca>
To:     Long Li <longli@microsoft.com>
Cc:     Dexuan Cui <decui@microsoft.com>,
        KY Srinivasan <kys@microsoft.com>,
        Haiyang Zhang <haiyangz@microsoft.com>,
        Stephen Hemminger <sthemmin@microsoft.com>,
        Wei Liu <wei.liu@kernel.org>,
        "David S. Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Leon Romanovsky <leon@kernel.org>,
        "edumazet@google.com" <edumazet@google.com>,
        "shiraz.saleem@intel.com" <shiraz.saleem@intel.com>,
        Ajay Sharma <sharmaajay@microsoft.com>,
        "linux-hyperv@vger.kernel.org" <linux-hyperv@vger.kernel.org>,
        "netdev@vger.kernel.org" <netdev@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "linux-rdma@vger.kernel.org" <linux-rdma@vger.kernel.org>
Subject: Re: [Patch v4 03/12] net: mana: Handle vport sharing between devices
Message-ID: <20220720234209.GP5049@ziepe.ca>
References: <1655345240-26411-1-git-send-email-longli@linuxonhyperv.com>
 <1655345240-26411-4-git-send-email-longli@linuxonhyperv.com>
 <SN6PR2101MB13272044B91D6E37F7F5124FBF879@SN6PR2101MB1327.namprd21.prod.outlook.com>
 <PH7PR21MB3263F08C111C5D06C99CC32ACE869@PH7PR21MB3263.namprd21.prod.outlook.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <PH7PR21MB3263F08C111C5D06C99CC32ACE869@PH7PR21MB3263.namprd21.prod.outlook.com>
Precedence: bulk

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