Hi

On Tue, Sep 7, 2021 at 4:34 PM Peter Maydell <peter.maydell@linaro.org>
wrote:

> On Tue, 7 Sept 2021 at 13:23, <marcandre.lureau@redhat.com> wrote:
> >
> > From: Marc-André Lureau <marcandre.lureau@redhat.com>
> >
> > I was looking for such documentation, but couldn't find it.
>
> Yes; this is definitely something we should document, and in
> the build-platforms doc is as good a place as any.
>
> > Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> > ---
> >  docs/about/build-platforms.rst | 28 ++++++++++++++++++++++++++++
> >  meson.build                    |  2 +-
> >  2 files changed, 29 insertions(+), 1 deletion(-)
> >
> > diff --git a/docs/about/build-platforms.rst
> b/docs/about/build-platforms.rst
> > index 692323609e..bfe90e574e 100644
> > --- a/docs/about/build-platforms.rst
> > +++ b/docs/about/build-platforms.rst
> > @@ -29,6 +29,34 @@ The `Repology`_ site is a useful resource to identify
> >  currently shipped versions of software in various operating systems,
> >  though it does not cover all distros listed below.
> >
> > +Supported host CPUs
> > +-------------------
> > +
> > +Those host CPUs have a native TCG backend and are regularly tested:
>
> This is a list of host architectures, not CPUs.
>

Isn't it CPU architecture we are talking about? (CPU for short in the title)


> > +  .. list-table::
> > +   :header-rows: 1
> > +
> > +   * - CPU Family
>

 I'll change this to CPU Architecture

> +     - Accelerators
> > +   * - ARM
>
> The correct capitalization these days is "Arm", by the way :-)
>
>
ok

You also should split 64-bit and 32-bit Arm; we support
> KVM on 64-bit but not 32-bit.
>
>
When such a difference exists, I just added "(64 bit only)", see below for
x86.


> > +     - kvm, xen
> > +   * - MIPS
> > +     - kvm
> > +   * - PPC
> > +     - kvm
> > +   * - RISC-V
> > +     -
> > +   * - s390x
> > +     - kvm
> > +   * - SPARC
> > +     -
> > +   * - x86
> > +     - kvm, xen, hax, hvf (64 bit only), nvmm, whpx (64 bit only)
> > +
> > +Other architectures are not actively maintained. They use the slow and
> > +experimental TCG interpreter. They may be removed in future releases.
>
> This seems to be conflating TCG and the TCG interpreter.
> We should just list which architectures we support (proper)
> TCG for, and say that everything else is unsupported
> (not mentioning the TCG interpreter at all; using it is
> pretty much always a mistake IMHO).
>

ok


> The table also seems to me to be a bit confusing, because
> the introductory text suggests it's a list of the TCG
> support for each architecture, but the table itself lists
> only the non-TCG accelerators. I think we should just list
> all the accelerators supported for each host architecture.
>

All the architectures we support (in the list) have proper TCG, right?

>
> Perhaps we should also (eventually) have somewhere some text
> describing each accelerator in more detail, though probably
> not in this file. A docs/system/accels.rst that described all
> the accelerators with a paragraph or so for each, maybe ?
>

That could be really useful, but I am not up to the task at this point.

thanks