Re: QEMU features useful for Xen development?

[Peter Maydell <peter.maydell@xxxxxxxxxx>]

On Thu, 31 Aug 2023 at 11:32, Ayan Kumar Halder <ayankuma@xxxxxxx> wrote:
> On 31/08/2023 11:03, Peter Maydell wrote:
> > On Thu, 31 Aug 2023 at 10:53, Alex Bennée <alex.bennee@xxxxxxxxxx> wrote:
> >> Peter Maydell <peter.maydell@xxxxxxxxxx> writes:
> >>> On Thu, 31 Aug 2023 at 01:57, Stefano Stabellini <sstabellini@xxxxxxxxxx> 
> >>> wrote:
> >>>> As Xen is gaining R52 and R82 support, it would be great to be able to
> >>>> use QEMU for development and testing there as well, but I don't think
> >>>> QEMU can emulate EL2 properly for the Cortex-R architecture. We would
> >>>> need EL2 support in the GIC/timer for R52/R82 as well.

> >>> (What sort of board model would Xen want to use it with?)

> >> We already model a bunch of the mps2/mps3 images so I'm assuming adding
> >> the mps3-an536 would be a fairly simple step to do (mps2tz.c is mostly
> >> tweaking config values). The question is would it be a useful target for
> >> Xen?

> Yes, it will be helpful if Qemu can model this board. We have a
> downstream port of Xen on R52 (upstreaming is in progress).
>
> So, we can test the Qemu model with Xen.

Hi, all. I just wanted to provide an update on this. We've now
completed the mps3-an536 board model, and you can find it if
you check out the head-of-git QEMU. The new board will be in the
9.0 QEMU release, but if you have a chance to give it a spin now
we'll be able to fix any bugs or problems with it before the release.

The documentation for the board is here:
https://www.qemu.org/docs/master/system/arm/mps2.html
and it lists the limitations/missing features. (If any of those
are important let me know and we can look at scheduling the work
to fill them in.)

I'd also like to draw your attention to the note about the UART
ordering on the AN536; unfortunately the hardware setup is a bit
awkward here, so if you have an "I don't see any output" problem
make sure your guest is sending to the same UART you're asking
QEMU to show you the output from :-)

thanks
-- PMM