Re: [PATCH v1 6/8] vfio/type1: Bind guest page tables to host

[Jean-Philippe Brucker]

On Thu, Apr 02, 2020 at 08:05:29AM +0000, Liu, Yi L wrote:
> > > > > static long vfio_iommu_type1_ioctl(void *iommu_data,
> > > > >  		default:
> > > > >  			return -EINVAL;
> > > > >  		}
> > > > > +
> > > > > +	} else if (cmd == VFIO_IOMMU_BIND) {
> > > >
> > > > BIND what? VFIO_IOMMU_BIND_PASID sounds clearer to me.
> > >
> > > Emm, it's up to the flags to indicate bind what. It was proposed to
> > > cover the three cases below:
> > > a) BIND/UNBIND_GPASID
> > > b) BIND/UNBIND_GPASID_TABLE
> > > c) BIND/UNBIND_PROCESS
> > > <only a) is covered in this patch>
> > > So it's called VFIO_IOMMU_BIND.
> > 
> > but aren't they all about PASID related binding?
> 
> yeah, I can rename it. :-)

I don't know if anyone intends to implement it, but SMMUv2 supports
nesting translation without any PASID support. For that case the name
VFIO_IOMMU_BIND_GUEST_PGTBL without "PASID" anywhere makes more sense.
Ideally we'd also use a neutral name for the IOMMU API instead of
bind_gpasid(), but that's easier to change later.

Thanks,
Jean