Hi Marc, > > On 08/09/17 10:05, gengdongjiu wrote: > > Marc, > > Thanks for reply. > > > > On 2017/9/8 16:21, Marc Zyngier wrote: > >>> Marc, > >>> > >>> sorry I have another question for the PAN. [...] > There cannot be any userspace mapping at EL2 when non-VHE, so there cannot be any valid PAN setting. I repeat: there is not such thing as > PAN at EL2 when HCR_EL2.E2H==0. This bit *has no effect*. Just read the documentation (ARM DDI 0487B.a, D4.4.2). Thanks Marc's comments, I completely agree with you, I understand the architecture, in non-VHE, user space mapping only exists at EL1 and pointed by the ttbr0_el1. In the EL1, it uses ttbr0_el1 to point userspace page table, uses ttbr1_el1 to point kernel mapping. In the EL2, it uses ttbr0_el2 or vttbr_el2 for address translation, cannot use the ttbr0_el1. > > If you're going to change this kind of code, please start by understanding the architecture. OK, so I plant to remove the PAN setting at EL2 in non-VHE. > > M. > -- > Jazz is not dead. It just smells funny...
