Re: [PATCH 08/14] vfio: add vfio-pci-base class

[John Levon <john.levon@nutanix.com>]

On Thu, Apr 24, 2025 at 05:17:28PM +0200, Cédric Le Goater wrote:

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> On 4/9/25 15:48, John Levon wrote:
> > Split out parts of TYPE_VFIO_PCI into a base TYPE_VFIO_PCI_BASE. The
> > base type contains properties generic to all vfio-pci implementations
> > (although we have not yet introduced another subclass).
> > 
> > Note that currently there is no need for additional data for
> > TYPE_VFIO_PCI, so it shares the same C struct type as
> > TYPE_VFIO_PCI_BASE, VFIOPCIDevice.
> 
> I don't understand how the properties are distributed between the
> abstract vfio-pci base class and the vfio-pci class. What's the
> rationale ?

It's for properties that apply to all vfio pci classes, and those that are
specific to the kernel vfio pci implementation.

> Can you remind me why the vfio-pci class for vfio-user can not
> inherit directly from vfio-pci ?

For the above reason: we'd inherit many properties that don't work for
vfio-user.

regards
john