Re: [PATCH 09/15] x86/PVH: split pvh_setup_vmx_realmode_helpers()

[Roger Pau Monné <roger@xxxxxxxxxxxxxx>]

On Mon, Oct 12, 2026 at 10:24:07AM +0200, Jan Beulich wrote:
> All E820 manipulations want to happen before the initrd is placed, or else
> pvh_steal_ram() may steal from the tail part of it. While this is
> currently suitably ordered, mapping the initrd directly into Dom0 will
> want to happen ahead of pvh_populate_p2m(). Hence as a third step, split
> placing VMX data (if needed at all) from actually populating it.
> 
> Also move the invocation of pvh_setup_vmx_realmode_helpers() out of
> pvh_populate_p2m(). Make it unconditional as well, instead bailing from
> the function when pvh_place_vmx_realmode_helpers() wasn't called.

I'm overall happy with the idea of moving
pvh_setup_vmx_realmode_helpers() out of pvh_populate_p2m(), however I
would much rather prefer for us to keep two memory maps (the real one
in the domain struct), plus a temporary one that signals used memory,
rather than doing allocation vs placement in two steps.  Having to
add custom {acpi,vmx}_info structures for each metadata we want to
place seems strictly worse than keeping two memory maps.

Thanks, Roger.