Re: [PATCH net-next 12/19] devlink: Introduce mdev port flavour

From: Jiri Pirko <jiri@resnulli.us>
To: Jakub Kicinski <jakub.kicinski@netronome.com>
Cc: Parav Pandit <parav@mellanox.com>,
	"alex.williamson@redhat.com" <alex.williamson@redhat.com>,
	"davem@davemloft.net" <davem@davemloft.net>,
	"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
	"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
	Saeed Mahameed <saeedm@mellanox.com>,
	"kwankhede@nvidia.com" <kwankhede@nvidia.com>,
	"leon@kernel.org" <leon@kernel.org>,
	"cohuck@redhat.com" <cohuck@redhat.com>,
	Jiri Pirko <jiri@mellanox.com>,
	"linux-rdma@vger.kernel.org" <linux-rdma@vger.kernel.org>
Subject: Re: [PATCH net-next 12/19] devlink: Introduce mdev port flavour
Date: Fri, 8 Nov 2019 10:30:01 +0100	[thread overview]
Message-ID: <20191108093001.GA6990@nanopsycho> (raw)
In-Reply-To: <20191107212024.61926e11@cakuba>

Fri, Nov 08, 2019 at 03:20:24AM CET, jakub.kicinski@netronome.com wrote:
>On Fri, 8 Nov 2019 01:44:53 +0000, Parav Pandit wrote:

[...]

>> > > > > @@ -6649,6 +6678,9 @@ static int  
>> > > > __devlink_port_phys_port_name_get(struct devlink_port *devlink_port,  
>> > > > >  		n = snprintf(name, len, "pf%uvf%u",
>> > > > >  			     attrs->pci_vf.pf, attrs->pci_vf.vf);
>> > > > >  		break;
>> > > > > +	case DEVLINK_PORT_FLAVOUR_MDEV:
>> > > > > +		n = snprintf(name, len, "p%s", attrs->mdev.mdev_alias);  
>> > > >
>> > > > Didn't you say m$alias in the cover letter? Not p$alias?
>> > > >  
>> > > In cover letter I described the naming scheme for the netdevice of the
>> > > mdev device (not the representor). Representor follows current unique
>> > > phys_port_name method.  
>> > 
>> > So we're reusing the letter that normal ports use?
>> >  
>> I initially had 'm' as prefix to make it easy to recognize as mdev's port, instead of 'p', but during internal review Jiri's input was to just use 'p'.
>
>Let's way for Jiri to weigh in then.

Hmm, it's been so far I can't really recall. But looking at what we have
now:
DEVLINK_PORT_FLAVOUR_PHYSICAL "p%u"/"p%us%u"
DEVLINK_PORT_FLAVOUR_PCI_PF   "pf%u"
DEVLINK_PORT_FLAVOUR_PCI_VF   "pf%uvf%u"
For mdev, the ideal format would be:
"pf%um%s" or "pf%uvf%um%s", but that would be too long.
I guess that "m%s" is fine.
"p" is probably not a good idea as phys ports already have that.

[...]