On 05/24/18 11:11, Peter Maydell wrote: > On 23 May 2018 at 21:52, Laszlo Ersek <ler...@redhat.com> wrote: >> On 05/23/18 22:40, Auger Eric wrote: >>> On 05/23/2018 07:45 PM, Laszlo Ersek wrote: >> >>>> Regarding the second patch, I do believe we need "more sophistication" >>>> there. For example, I guess it could be possible to distinguish "-cpu >>>> cortex-a15" from "-cpu cortex-a57" somehow, and stick with the low/small >>>> ECAM in the former case. (The 32-bit firmware already runs on cortex-a15 >>>> only, and not on cortex-a57, according to my testing.) >>> >>> So we should detect we are in ACPI boot + aarch32 mode to force legacy >>> ECAM region, right? >> >> Agree about the aarch32 subcondition. >> >> However, "ACPI vs. DT" is not the right "other" subcondition here; >> instead we should (minimally) check "firmware vs. no firmware". See the >> "firmware_loaded" boolean field. > > Won't it also break a guest which is just Linux loaded not via > firmware which is an aarch32 kernel without LPAE support?
Does such a thing exist? (I honestly have no clue.) If it does, then there are two options: - don't enable the new ECAM range by default (always take an explicit option), - offer both ECAM ranges and let the guest pick one (I should add that I have no idea whether exposing such *alternatives* is possible via DT and ACPI; i.e., "pick one but not both"). Thanks Laszlo