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

[Baolu Lu]

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@xxxxxxxxxxxxxxx>
> ---
>   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?

>   	if (level == 5)
>   		flags |= PASID_FLAG_FL5LP;
>   

Best regards,
baolu