Re: [PATCH rfcv1 1/6] backends/iommufd_device: introduce IOMMUFDDevice

[Cédric Le Goater]

On 1/19/24 08:31, Duan, Zhenzhong wrote:
> > -----Original Message-----
> > From: Eric Auger <eric.auger@redhat.com>
> > Subject: Re: [PATCH rfcv1 1/6] backends/iommufd_device: introduce
> > IOMMUFDDevice
> >
> >
> >
> > On 1/15/24 11:13, Zhenzhong Duan wrote:
> > > IOMMUFDDevice represents a device in iommufd and can be used as
> > > a communication interface between devices (i.e., VFIO, VDPA) and
> > > vIOMMU.
> > >
> > > Currently it includes iommufd handler and device id information
> > > which could be used by vIOMMU to get hw IOMMU information.
> > >
> > > In future nested translation support, vIOMMU is going to have
> > > more iommufd related operations like allocate hwpt for a device,
> > > attach/detach hwpt, etc. So IOMMUFDDevice will be further expanded.
> > >
> > > IOMMUFDDevice is willingly not a QOM object because we don't want
> > > it to be visible from the user interface.
> > >
> > > Introduce a helper iommufd_device_init to initialize IOMMUFDDevice.
> > >
> > > Originally-by: Yi Liu <yi.l.liu@intel.com>
> > > Signed-off-by: Yi Sun <yi.y.sun@linux.intel.com>
> > > Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
> > > ---
> > >   MAINTAINERS                     |  4 +--
> > >   include/sysemu/iommufd_device.h | 31 ++++++++++++++++++++
> > >   backends/iommufd_device.c       | 50
> > +++++++++++++++++++++++++++++++++
> > Maybe it is still time to move the iommufd files in a sepate dir, under
> > hw at the same level as vfio.
> >
> > Thoughts?
>
> Any reason for the movement? Hw dir contains entries to emulate different
> Devices. Iommufd is not a real device. It's more a backend.

I would include the new services in the existing iommufd .[ch] files.
No need for a new file since the changes are all related to the IOMMUFD
device usage.

Thanks,

C.