On 2023/4/1 7:11, Jacob Pan wrote:
Supervisor Request Enable (SRE) bit in a PASID entry is for permission checking on DMA requests. When SRE = 0, DMA with supervisor privilege will be blocked. However, for in-kernel DMA this is not necessary in that we are targeting kernel memory anyway. There's no need to differentiate user and kernel for in-kernel DMA. Let's use non-privileged (user) permission for all PASIDs used in kernel, it will be consistent with DMA without PASID (RID_PASID) as well. Signed-off-by: Jacob Pan<jacob.jun.pan@xxxxxxxxxxxxxxx>
Reviewed-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx> Best regards, baolu
