Subject: Re: [PATCH 0/7] Introduce vdpa management tool

From: "Michael S. Tsirkin" <[email-masked]>
Date: Wed, 16 Dec 2020 04:13:51 -0500

On Tue, Nov 17, 2020 at 07:51:56PM +0000, Parav Pandit wrote:
> 
> 
> > From: Jakub Kicinski <[email-masked]>
> > Sent: Tuesday, November 17, 2020 3:53 AM
> > 
> > On Thu, 12 Nov 2020 08:39:58 +0200 Parav Pandit wrote:
> > > FAQs:
> > > -----
> > > 1. Where does userspace vdpa tool reside which users can use?
> > > Ans: vdpa tool can possibly reside in iproute2 [1] as it enables user
> > > to create vdpa net devices.
> > >
> > > 2. Why not create and delete vdpa device using sysfs/configfs?
> > > Ans:
> > 
> > > 3. Why not use ioctl() interface?
> > 
> > Obviously I'm gonna ask you - why can't you use devlink?
> > 
> This was considered.
> However it seems that extending devlink for vdpa specific stats, devices, config sounds overloading devlink beyond its defined scope.

kuba what's your thinking here? Should I merge this as is?

> > > Next steps:
> > > -----------
> > > (a) Post this patchset and iproute2/vdpa inclusion, remaining two
> > > drivers will be coverted to support vdpa tool instead of creating
> > > unmanaged default device on driver load.
> > > (b) More net specific parameters such as mac, mtu will be added.
> > 
> > How does MAC and MTU belong in this new VDPA thing?
> MAC only make sense when user wants to run VF/SF Netdev and vdpa together with different mac address.
> Otherwise existing devlink well defined API to have one MAC per function is fine.
> Same for MTU, if queues of vdpa vs VF/SF Netdev queues wants have different MTU it make sense to add configure per vdpa device.