Re: [PATCH 6/6] iommu/vt-d: Add domain_alloc_user op

Jason Gunthorpe
2023-09-20T13:05:33Z

On Wed, Sep 20, 2023 at 01:28:41PM +0800, Baolu Lu wrote:
> >
> > diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
> > index 5db283c17e0d..491bcde1ff96 100644
> > --- a/drivers/iommu/intel/iommu.c
> > +++ b/drivers/iommu/intel/iommu.c
> > @@ -4074,6 +4074,25 @@ static struct iommu_domain *intel_iommu_domain_alloc(unsigned type)
> > return NULL;
> > }
> > +static struct iommu_domain *
> > +intel_iommu_domain_alloc_user(struct device *dev, u32 flags)
> > +{
> > + struct iommu_domain *domain;
> > + struct intel_iommu *iommu;
> > +
> > + iommu = device_to_iommu(dev, NULL, NULL);
> > + if (!iommu)
> > + return ERR_PTR(-ENODEV);
> > +
> > + if ((flags & IOMMU_HWPT_ALLOC_NEST_PARENT) && !ecap_nest(iommu->ecap))
> > + return ERR_PTR(-EOPNOTSUPP);

There is a check missing for supported flags

if (flags & (~IOMMU_HWPT_ALLOC_NEST_PARENT))
return ERR_PTR(-EOPNOTSUPP);

> > +
> > + domain = iommu_domain_alloc(dev->bus);
>
> No need to bounce between core and driver. Just,
>
> intel_iommu_domain_alloc(IOMMU_DOMAIN_UNMANAGED);
>
> and fully initialize it before return.

If you are going to do that then intel_iommu_domain_alloc() should
fully initialize the domain, not here.

Jason