On 09/02/15 10:08, Gerd Hoffmann wrote: > On Di, 2015-09-01 at 21:10 +0100, Peter Maydell wrote: >> On 1 September 2015 at 20:13, Gabriel L. Somlo <so...@cmu.edu> wrote: >>> Also, since I'll be tinkering with fw_cfg again, and you mentioned >>> using DT on arm and ACPI on x86 to auto-detect the presence (and location) >>> of fw_cfg from the guest-side in a related thread: >> >> I meant DT or ACPI on ARM, actually. I don't know what the x86 >> approach is for fw_cfg but I think it's just "known address". > > Yes, "known address". And given that the firmware actually loads the > acpi tables via fw_cfg that is very unlikely to change. Adding it to > the acpi tables might be useful nevertheless so the guest os knows the > ioports are in use. > > I think on arm the acpi situation is the same, but I think firmware > detecting the location via DT should work without chicken&egg problems.
First of all I apologize for lagging severely behind this thread; in practice I can't read emails longer than 20 lines or so. This one qualifies, so I'll respond: Yes, on qemu-system-(arm|aarch64) -M virt, detecting the fw_cfg registers via DT should continue to work without any dependencies. Thanks Laszlo
