[Intel-gfx] [PATCH v5 06/10] vfio-iommufd: Add helper to retrieve iommufd_ctx and devid for vfio_device

[Liu, Yi L]

> From: Alex Williamson <alex.williamson at redhat.com>
> Sent: Thursday, May 18, 2023 2:15 AM
> 
> On Sat, 13 May 2023 06:21:32 -0700
> Yi Liu <yi.l.liu at intel.com> wrote:
> 
> > This is needed by the vfio-pci driver to report affected devices in the
> > hot reset for a given device.
> >
> > Signed-off-by: Yi Liu <yi.l.liu at intel.com>
> > ---
> >  drivers/iommu/iommufd/device.c | 24 ++++++++++++++++++++++++
> >  drivers/vfio/iommufd.c         | 20 ++++++++++++++++++++
> >  include/linux/iommufd.h        |  6 ++++++
> >  include/linux/vfio.h           | 14 ++++++++++++++
> >  4 files changed, 64 insertions(+)
> >
> > diff --git a/drivers/iommu/iommufd/device.c b/drivers/iommu/iommufd/device.c
> > index 4f9b2142274c..81466b97023f 100644
> > --- a/drivers/iommu/iommufd/device.c
> > +++ b/drivers/iommu/iommufd/device.c
> > @@ -116,6 +116,18 @@ void iommufd_device_unbind(struct iommufd_device *idev)
> >  }
> >  EXPORT_SYMBOL_NS_GPL(iommufd_device_unbind, IOMMUFD);
> >
> > +struct iommufd_ctx *iommufd_device_to_ictx(struct iommufd_device *idev)
> > +{
> > +	return idev->ictx;
> > +}
> > +EXPORT_SYMBOL_NS_GPL(iommufd_device_to_ictx, IOMMUFD);
> > +
> > +u32 iommufd_device_to_id(struct iommufd_device *idev)
> > +{
> > +	return idev->obj.id;
> > +}
> > +EXPORT_SYMBOL_NS_GPL(iommufd_device_to_id, IOMMUFD);
> > +
> >  static int iommufd_device_setup_msi(struct iommufd_device *idev,
> >  				    struct iommufd_hw_pagetable *hwpt,
> >  				    phys_addr_t sw_msi_start)
> > @@ -463,6 +475,18 @@ void iommufd_access_destroy(struct iommufd_access
> *access)
> >  }
> >  EXPORT_SYMBOL_NS_GPL(iommufd_access_destroy, IOMMUFD);
> >
> > +struct iommufd_ctx *iommufd_access_to_ictx(struct iommufd_access *access)
> > +{
> > +	return access->ictx;
> > +}
> > +EXPORT_SYMBOL_NS_GPL(iommufd_access_to_ictx, IOMMUFD);
> > +
> > +u32 iommufd_access_to_id(struct iommufd_access *access)
> > +{
> > +	return access->obj.id;
> > +}
> > +EXPORT_SYMBOL_NS_GPL(iommufd_access_to_id, IOMMUFD);
> > +
> >  int iommufd_access_attach(struct iommufd_access *access, u32 ioas_id)
> >  {
> >  	struct iommufd_ioas *new_ioas;
> > diff --git a/drivers/vfio/iommufd.c b/drivers/vfio/iommufd.c
> > index c1379e826052..a18e920be164 100644
> > --- a/drivers/vfio/iommufd.c
> > +++ b/drivers/vfio/iommufd.c
> > @@ -105,6 +105,26 @@ void vfio_iommufd_unbind(struct vfio_device *vdev)
> >  		vdev->ops->unbind_iommufd(vdev);
> >  }
> >
> > +struct iommufd_ctx *vfio_iommufd_physical_ictx(struct vfio_device *vdev)
> > +{
> > +	if (vdev->iommufd_device)
> > +		return iommufd_device_to_ictx(vdev->iommufd_device);
> > +	if (vdev->noiommu_access)
> > +		return iommufd_access_to_ictx(vdev->noiommu_access);
> > +	return NULL;
> > +}
> > +EXPORT_SYMBOL_GPL(vfio_iommufd_physical_ictx);
> > +
> > +int vfio_iommufd_physical_devid(struct vfio_device *vdev)
> > +{
> > +	if (vdev->iommufd_device)
> > +		return iommufd_device_to_id(vdev->iommufd_device);
> > +	if (vdev->noiommu_access)
> > +		return iommufd_access_to_id(vdev->noiommu_access);
> > +	return -EINVAL;
> > +}
> > +EXPORT_SYMBOL_GPL(vfio_iommufd_physical_devid);
> 
> I think these exemplify that it would be better if both emulated and
> noiommu use the same iommufd_access pointer.  Thanks,

Sure. Then I shall rename this helper. vfio_iommufd_device_devid()
What about your opinion?

Regards,
Yi Liu