Re: [Qemu-devel] [PATCH 0/3] target/arm: Support EL1 AArch32 guest under AArch64 EL2

[Edgar E. Iglesias]

On Tue, Jan 10, 2017 at 06:44:06PM +0000, Peter Maydell wrote:
> The GICv3 virt patchset is sufficient to run a 64-bit guest under
> a 64-bit host kernel. To run 32-bit guests under the 64-bit host
> you need a few more things:
>  * data aborts from AArch32 need to provide instruction syndrome info
>    to the hypervisor
>  * the AArch32 interrupt code needs to handle VIRQ and VFIQ
>  * we need a DBGVCR32_EL2 register, because Linux's EL2 code uses
>    it to context-switch AArch32 DBGVCR between guests
> 
> This patchset sits on top of the gicv3-virt patchset and is
> sufficient to run a Linux 32-bit guest under 64-bit Linux host.

Cool stuff Peter, I didn't think we were this close for this to work!

32bit hypervisors would be cool too but I'm guessing there's quite a bit
of work before that works...

Cheers,
Edgar

> 
> Git branch with the whole lot:
>  https://git.linaro.org/people/peter.maydell/qemu-arm.git aarch32-guest
> 
> 
> Peter Maydell (3):
>   target/arm: A32, T32: Create Instruction Syndromes for Data Aborts
>   target/arm: Handle VIRQ and VFIQ in arm_cpu_do_interrupt_aarch32()
>   target/arm: Implement DBGVCR32_EL2 system register
> 
>  target/arm/helper.c    |  21 +++++
>  target/arm/translate.c | 213 
> ++++++++++++++++++++++++++++++++++++-------------
>  2 files changed, 178 insertions(+), 56 deletions(-)
> 
> -- 
> 2.7.4
>