Re: [PATCH 4/6] iommufd/hw_pagetable: Support allocating nested parent domain

[Yi Liu]

On 2023/9/20 13:05, Baolu Lu wrote:
> On 9/19/23 5:25 PM, Yi Liu wrote:
> > This extends IOMMU_HWPT_ALLOC to allocate domains used as parent (stage-2)
> > in nested translation.
> >
> > Signed-off-by: Yi Liu <yi.l.liu@xxxxxxxxx>
> > ---
> >   drivers/iommu/iommufd/hw_pagetable.c | 5 ++++-
> >   1 file changed, 4 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/iommu/iommufd/hw_pagetable.c 
> > b/drivers/iommu/iommufd/hw_pagetable.c
> > index 5be7a31cbd9c..26a8a818ffa3 100644
> > --- a/drivers/iommu/iommufd/hw_pagetable.c
> > +++ b/drivers/iommu/iommufd/hw_pagetable.c
> > @@ -83,6 +83,9 @@ iommufd_hw_pagetable_alloc(struct iommufd_ctx *ictx, 
> > struct iommufd_ioas *ioas,
> >       lockdep_assert_held(&ioas->mutex);
> > +    if ((flags & IOMMU_HWPT_ALLOC_NEST_PARENT) && !ops->domain_alloc_user)
> > +        return ERR_PTR(-EOPNOTSUPP);
> > +
> >       hwpt = iommufd_object_alloc(ictx, hwpt, IOMMUFD_OBJ_HW_PAGETABLE);
> >       if (IS_ERR(hwpt))
> >           return hwpt;
> > @@ -154,7 +157,7 @@ int iommufd_hwpt_alloc(struct iommufd_ucmd *ucmd)
> >       struct iommufd_ioas *ioas;
> >       int rc;
> > -    if (cmd->flags || cmd->__reserved)
> > +    if (cmd->flags & ~IOMMU_HWPT_ALLOC_NEST_PARENT || cmd->__reserved)
> >           return -EOPNOTSUPP;
>
> Need a parenthesis here, otherwise the compiler will interpret it as a
> different condition.
>
>      if ((cmd->flags & ~IOMMU_HWPT_ALLOC_NEST_PARENT) || cmd->__reserved)
>          return -EOPNOTSUPP;

ok.

--
Regards,
Yi Liu