On 03/08/17 18:12, Daniel P. Berrange wrote: > On Wed, Mar 08, 2017 at 06:05:02PM +0100, Andrea Bolognani wrote: >> On Wed, 2017-03-08 at 16:00 +0000, Daniel P. Berrange wrote: >>>> So far, libvirt has assumed that only x86 supports ACPI, >>>> but that's inaccurate since aarch64 supports it too. >>> >>> IIUC, it only supports ACPI if using the AAVMF firmware, right ? >> >> My current understanding is that ACPI on aarch64 requires >> UEFI, not necessarily AAVMF. I'll admit I haven't really >> considered other QEMU-compatible UEFI implementations, >> though, assuming they exist. >> >> Laszlo? :) >> >>> I know that is the preferred firmware for aarch64, but IIUC it is >>> not a hard requirement by QEMU. So even if we advertize it in the >>> capabilities, we might need to still validate during CLI building >>> that we're actually using AAVMF firmware. >> >> We currently require that ACPI is available when using UEFI, >> even though as mentioned above I believe it should really >> be the other way around. >> >> In any case, how would we validate that the pflash file >> we're passing to QEMU does indeed contain AAVMF? > > I don't think we can, at least not right now. > > For the secure boot problem, we previously discussed create a standardized > metadata file to accompany firmware images, which would declare what QEMU > features the firmware supported. ACPI could fit into that world. > > It is probably time we got serious about actually doing this.... > > Meanwhile, we can just assume it supports ACPI. > > The scenario I was actually thinking of was direct kernel boot, > rather than non-AAVMF impls of UEFI. > > IOW, where you just pass -kernel/-initrd/-dtb to QEMU and no firmware > file. In that case, we should report an error if <acpi/> is requested > in the XML IIUC. Direct kernel boot without UEFI firmware should indeed conflict with <acpi/>, yes; there's no firmware to install the tables for the kernel. Direct kernel boot with UEFI firmware should permit <acpi/>. The firmware starts, does its thing (including installation of ACPI tables), then grabs the kernel from fw_cfg, and launches it. The kernel will see the tables. Thanks Laszlo -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list
