On 6 November 2014 14:44, Peter Maydell peter.maydell@linaro.org wrote:
We need ACPI guest support in QEMU for AArch64 over here, with all features (including the ability to run ACPI code and add specific tables), for ACPI-based guests.
The plan for providing ACPI to guests is that we run a UEFI BIOS blob which is what is responsible for providing ACPI and UEFI runtime services to guests which need them. (The UEFI blob finds out about its hardware by looking at a device tree that QEMU passes it, but that's a detail between QEMU and its bios blob). This pretty much looks like what x86 QEMU used to do with ACPI for a very long time, so we know it's a feasible approach.
Hi Peter,
The rational in the proposed approach is meant for cases where the user does not want to rely on external firmware layers. While UEFI could do what you are describing, the point is to avoid this not so trivial overhead in the booting process. Especially in the case of thin guests, where another software dependency is undesired.
Regards.