Re: [Qemu-devel] [PATCH 00/23] arm: Add virtualization to GICv3, and enable EL2 on 64-bit CPUs

[Andrew Jones]

On Tue, Dec 13, 2016 at 10:36:01AM +0000, Peter Maydell wrote:
> This patchset adds support for the Virtualization extensions to QEMU's
> GICv3 emulation. This was the last missing piece that was stopping
> us from turning on the EL2 support in the CPU model, so the patchset
> also adds support for enabling it all on the virt board via the
> '-machine virtualization=on' option.
> 
> The result works well enough to allow booting a KVM outer guest kernel
> and then running QEMU + an inner guest under KVM inside it. The outer
> guest KVM also passes the kvm-unit-tests GIC tests.
>

I've started some testing with this. When I boot an outer (L1) kernel
with more than one cpu allocated I get

[    3.441908] CPU: CPUs started in inconsistent modes
[    3.442787] ------------[ cut here ]------------
[    3.445434] WARNING: CPU: 0 PID: 1 at arch/arm64/kernel/smp.c:418 
smp_cpus_done+0x80/0xa0
...

and KVM does not init. Booting with only one cpu I see we do start in EL2
and KVM does init. I'm booting the L1 kernel through UEFI (AAVMF). Also,
my L1 guest kernel is 4.9 based, but not pure upstream. I can try a more
pure 4.9 kernel with a defconfig later.

Thanks,
drew