Re: [Qemu-devel] [Qemu-arm] [PATCH 00/10] target/arm: Some pieces of support for 32-bit Hyp mode

[Peter Maydell]

On 14 August 2018 at 13:42, Peter Maydell <address@hidden> wrote:
> Now we have virtualization support in the GICv2 emulation,
> I thought I'd have a look at how much we were still missing
> for being able to enable EL2 support for AArch32.
> This set of patches fixes some minor missing pieces:
>  * various small bugs in cp15 registers or places where
>    we were missing the 32-bit version of a 64-bit register
>  * a bugfix for MSR/MRS (banked), which were not allowing
>    Hyp mode to access ELR_Hyp
>  * implementation of the ERET instruction for A32/T32
>  * support for taking exceptions to Hyp mode (the largest
>    of these missing bits)
>
> This isn't complete, but I thought I'd push these patches
> out for review. My test setup is that I have another
> couple of patches, one which fixes up hw/arm/boot.c to
> boot AArch32 kernels in Hyp mode if it exists, and one
> which sets ARM_FEATURE_EL2 on our A15 model. With those I
> can get an outer kernel to boot with KVM support and try
> to run an inner guest kernel. The inner kernel boots OK
> but gets random segfaults in its userspace -- I haven't
> tracked down why this is yet...

I've put patches 1, 2, 4, 6, 7, 8, 9:

>   target/arm: Correct typo in HAMAIR1 regdef name
>   target/arm: Add missing .cp = 15 to HMAIR1 and HAMAIR1 regdefs
>   target/arm: Implement RAZ/WI HACTLR2
>   target/arm: Implement AArch32 HVBAR
>   target/arm: Implement AArch32 HCR and HCR2
>   target/arm: Implement AArch32 Hyp FARs
>   target/arm: Implement ESR_EL2/HSR for AArch32 and no-EL2
>   target/arm: Permit accesses to ELR_Hyp from Hyp mode via MSR/MRS
>     (banked)
>   target/arm: Implement AArch32 ERET instruction

into target-arm.next.

Patches 3, 5, 10 had issues in code review and I'll
rework those and send a v2 at some point:

>   target/arm: Implement RAZ/WI HACTLR2
>   target/arm: Implement AArch32 HCR and HCR2
>   target/arm: Implement support for taking exceptions to Hyp mode

thanks
-- PMM