Re: [PATCH 2/4] iommu/vt-d: Use non-privileged mode for all PASIDs

[Jacob Pan <jacob.jun.pan@linux.intel.com>]

Hi Baolu,

On Thu, 2 Mar 2023 22:11:36 +0800, Baolu Lu <baolu.lu@linux.intel.com>
wrote:

> On 2023/3/2 8:59, Jacob Pan wrote:
> > For in-kernel DMA, use non-privileged access for all PASIDs to be
> > consistent with RID_PASID.
> > There's no need to differentiate user and kernel for in-kernel DMA. >
> > Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
> > ---
> >   drivers/iommu/intel/iommu.c | 2 --
> >   1 file changed, 2 deletions(-)
> > 
> > diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
> > index a0cb3bc851ac..9e3c056e392d 100644
> > --- a/drivers/iommu/intel/iommu.c
> > +++ b/drivers/iommu/intel/iommu.c
> > @@ -2334,8 +2334,6 @@ static int domain_setup_first_level(struct
> > intel_iommu *iommu, if (level != 4 && level != 5)
> >   		return -EINVAL;
> >   
> > -	if (pasid != PASID_RID2PASID)
> > -		flags |= PASID_FLAG_SUPERVISOR_MODE;  
> 
> With above removed, PASID_FLAG_SUPERVISOR_MODE is not used anywhere?
> Perhaps you can cleanup it to avoid dead code?
good point, we could remove pasid_set_sre() related code for FL,SL, and PT.

Thanks,

Jacob