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Date:   Wed, 22 Sep 2021 20:52:08 -0300
From:   Jason Gunthorpe <jgg@nvidia.com>
To:     "Tian, Kevin" <kevin.tian@intel.com>
Cc:     Alex Williamson <alex.williamson@redhat.com>,
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Subject: Re: [RFC 03/20] vfio: Add vfio_[un]register_device()
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On Wed, Sep 22, 2021 at 11:45:33PM +0000, Tian, Kevin wrote:
> > From: Alex Williamson <alex.williamson@redhat.com>

> btw I realized another related piece regarding to the new layout that
> Jason suggested, which have sys device node include a link to the vfio
> devnode:
> 
> 	/sys/bus/pci/devices/DDDD:BB:DD.F/vfio/vfioX/dev
> 
> This for sure requires specific vfio driver support to get the link
> established.

It doesn't. Just set the parent device of the vfio_device's struct
device to the physical struct device that vfio is already tracking -
ie the struct device providing the IOMMU. The driver core takes care
of everything else.

Jason