Re: [Qemu-devel] [PATCH] Add Qemu A15 minimal support for ARM KVM

[Peter Maydell]

On 29 September 2011 08:30,  <address@hidden> wrote:
> From: Bill Carson <address@hidden>
>
> This patch add some A15 codes which enables ARM KVM could run
> Guest OS build with Versatile Express Cortex-A15x4 tile.

Thanks for sending this; I have somewhat belatedly written
up some comments on it.

I see the a15mpcore.c code is based on a version of mpcore.c
which predates the MemoryRegion API changes -- we'll need to
update it to use MemoryRegions.

There are some relics of 11MPCore peripherals lurking in there
which need to be taken out. (I think we should probably clean
up mpcore.c to separate out A9 from 11MPCore, incidentally.)

The vexpress A9 and A15 init functions can probably share
code although I haven't looked too closely there.

For QEMU TCG we're going to want to model at least some
of the cp15 registers (although probably mostly dummy
implementations).

The A15 generic timer is accessed via cp15 registers rather
than being memory mapped -- we need to decide which side of
the KVM/QEMU boundary the model of that should live. (I'm
guessing the right answer is "qemu side" which means we'll
need an ABI between KVM and QEMU to pass (some) cp15 accesses
through.)

thanks again
-- PMM