On 3 March 2016 at 14:48, Sergey Fedorov <serge.f...@gmail.com> wrote: > On 03.03.2016 16:49, Peter Maydell wrote: >> On 2 March 2016 at 19:19, Sergey Fedorov <serge.f...@gmail.com> wrote: >>> On 02.03.2016 21:04, Sergey Sorokin wrote: >>>> Qemu reports translation fault on 1st level instead of 0th level in case of >>>> AArch64 address translation if the translation table walk is disabled or >>>> the address is in the gap between the two regions. >>> It's probably not a very clear description in the commit message. IIUC, >>> level 0 fault is reported in case of any fault from TTBR in AArch64 state. >> Yes (though you mean "under an AArch64 translation regime"). Conversely, the >> only fault reported at level 0 under an AArch32 translation regime is >> the AddressSize fault (for bad addresses in TTBR0/1), which we don't >> currently implement. >> >> There's also a code path later in the function that does >> level = va_size == 64 ? 0 : 1; >> >> but I'm not sure it's worth rearranging that code to avoid the >> duplication of "what level do we report this kind of fault at?". > > Right, but actually I think this patch is going to fix the two "goto > do_fault" cases which can happen before this "level = va_size == 64 ? 0 > : 1", namely the EDP check and the check for virtual address which is in > the gap between TTBR0 and TTBR1 regions.
Yes, this patch is definitely fixing a bug; I'm just mentioning that other code path because it seems to be the result of previously fixing the bug for a particular special case... -- PMM