Re: [PATCH v7 2/7] tools/xl: Add altp2m_count parameter

[Petr Beneš <w1benny@xxxxxxxxx>]

On Mon, Jul 7, 2025 at 3:35 PM Anthony PERARD <anthony@xxxxxxxxxxxxxx> wrote:
>
> It seems that altp2m_count is going to be used for the creation of all
> guest, right? That is in addition to HVM, it will be also used for PV
> guest and on Arm, and any other architectures that could be added.
>
> Anthony PERARD

I'm suggesting to use what is used elsewhere in the libxl_create.c:

(https://github.com/xen-project/xen/blob/9b0f0f6e235618c2764e925b58c4bfe412730ced/tools/libs/light/libxl_create.c#L1233
and 
https://github.com/xen-project/xen/blob/9b0f0f6e235618c2764e925b58c4bfe412730ced/tools/libs/light/libxl_create.c#L1241)

        ((d_config->c_info.type == LIBXL_DOMAIN_TYPE_HVM &&
          libxl_defbool_val(d_config->b_info.u.hvm.altp2m))

In other words, add check for the LIBXL_DOMAIN_TYPE_HVM type before
calling that offending libxl_defbool_val(). Would that be okay?

>  What should be the value of altp2m_count in all this case, if altp2m is only
> set on x86 HVM guest?

0. Similarly to other fields that are implemented only for x86, but
are available (and technically implementable) elsewhere - like altp2m
field, vmtrace_buf_kb, etc.

P.