Re: [PATCH 05/24] iommu/amd: Allocate Guest IDs for IOMMUFD vIOMMU instances

[Suthikulpanit, Suravee]

On 8/25/2026 12:24 AM, Jason Gunthorpe wrote:
> > [ ... 73 lines skipped ... ]
> > +int amd_iommu_gid_alloc(struct amd_iommu *iommu)
> > +{
> > +	int ret = ida_alloc_range(&iommu->gid_ida, 1, VIOMMU_MAX_GID, GFP_KERNEL);
> > +
> > +	if (ret < 0)
> > +		pr_err("%s: Failed to allocate guest ID (devid=%#x)\n",
> > +		       __func__, iommu->devid);
>
> Don't print on user triggerable failure paths

Ok.
> > [ ... 19 lines skipped ... ]
> > @@ -43,13 +43,37 @@ size_t amd_iommufd_get_viommu_size(struct device *dev, enum iommu_viommu_type vi
> >   int amd_iommufd_viommu_init(struct iommufd_viommu *viommu, struct iommu_domain *parent,
> >   			    const struct iommu_user_data *user_data)
> >   {
> > +	int ret;
> >   	unsigned long flags;
> > +	struct iommu_viommu_amd data = {};
> >   	struct protection_domain *pdom = to_pdomain(parent);
> >   	struct amd_iommu_viommu *aviommu = container_of(viommu, struct amd_iommu_viommu, core);
> > +	struct amd_iommu *iommu = container_of(viommu->iommu_dev, struct amd_iommu, iommu);
> >   
> >   	xa_init_flags(&aviommu->gdomid_array, XA_FLAGS_ALLOC1);
> >   	aviommu->parent = pdom;
> >   
> > +	if (!user_data)
> > +		return -EINVAL;
> > +
> > +	ret = iommu_copy_struct_from_user(&data, user_data,
> > +					  IOMMU_VIOMMU_TYPE_AMD,
> > +					  out_vfmmio_mmap_offset);
> > +	if (ret)
> > +		return ret;
> > +
> > +	ret = amd_iommu_gid_alloc(iommu);
> > +	if (ret < 0)
> > +		goto err_gid;
> > +	aviommu->gid = ret;
> > +	pr_debug("%s: gid=%#x", __func__, aviommu->gid);
> > +
> > +	ret = iommu_copy_struct_to_user(user_data, &data,
> > +					IOMMU_VIOMMU_TYPE_AMD,
> > +					out_vfmmio_mmap_offset);
> > +	if (ret)
> > +		goto err_init;
>
> These hunks doing the copy struct are probably in the wrong patch since
> nothing touches out_vfmmio_mmap_offset.

I'll move this to later patch where the out_vfmmio_mmap_offset being 
changed.

> Otherwise looks OK
>
> Reviewed-by: Jason Gunthorpe <jgg@xxxxxxxxxx>

Thanks,
Suravee