Re: [RFC] virt/acpi: set PSCI flag even when psci_conduit is disabled

[Peter Maydell]

On Fri, 3 Jul 2020 at 10:44, Heyi Guo <guoheyi@linux.alibaba.com> wrote:
>
> vms->psci_conduit being disabled only means PSCI is not implemented by
> qemu; it doesn't mean PSCI is not supported on this virtual machine.
> Actually vms->psci_conduit is set to disabled when vms->secure and
> firmware_loaded are both set, which means we will run ARM trusted
> firmware, which will definitely provide PSCI.
>
> The issue can be reproduced when running qemu in TCG mode with secure
> enabled, while using ARM trusted firmware + qemu virt UEFI as firmware
> binaries, and we can see secondary cores will not be waken up.

If you're using a real EL3 guest firmware then it's the job of
the guest firmware to provide a DTB to the guest EL2/EL1 that says
"and I support PSCI" if it supports PSCI, surely? QEMU can't tell
whether the EL3 code does or doesn't do that...

thanks
-- PMM