Re: [PATCH V1 vfio 0/9] Introduce a vfio driver over virtio devices

[Jason Gunthorpe <jgg@nvidia.com>]

On Mon, Oct 23, 2023 at 10:09:13AM -0600, Alex Williamson wrote:
> On Mon, 23 Oct 2023 12:42:57 -0300
> Jason Gunthorpe <jgg@nvidia.com> wrote:
> 
> > On Mon, Oct 23, 2023 at 09:33:23AM -0600, Alex Williamson wrote:
> > 
> > > > Alex,
> > > > Are you fine to leave the provisioning of the VF including the control 
> > > > of its transitional capability in the device hands as was suggested by 
> > > > Jason ?  
> > > 
> > > If this is the standard we're going to follow, ie. profiling of a
> > > device is expected to occur prior to the probe of the vfio-pci variant
> > > driver, then we should get the out-of-tree NVIDIA vGPU driver on board
> > > with this too.  
> > 
> > Those GPU drivers are using mdev not vfio-pci..
> 
> The SR-IOV mdev vGPUs rely on the IOMMU backing device support which
> was removed from upstream.  

It wasn't, but it changed forms.

mdev is a sysfs framework for managing lifecycle with GUIDs only.

The thing using mdev can call vfio_register_emulated_iommu_dev() or
vfio_register_group_dev(). 

It doesn't matter to the mdev stuff.

The thing using mdev is responsible to get the struct device to pass
to vfio_register_group_dev()

Jason