Re: [PATCH 00/13] microvm: add acpi support

[Gerd Hoffmann]

> > mounted.  Decided to use the "i8042: PNP: No PS/2 controller found."
> > line instead for a simple test (just check the kernel log timestamps,
> > three runs each).  The ACPI initialization is already done at that
> > point, so it should be useful nevertheless.  Here we go:
> > 
> > Without acpi:
> >   0.277710
> >   0.278852
> >   0.279520
> > 
> > With acpi:
> >   0.283917
> >   0.284262
> >   0.284836
> I wonder what would be difference with hw-reduced acpi

The kernel does a bunch of reads+writes at boot (roughly 20-30),
mostly timer ports, so probably while initializing the pm_timer
clocksource.  Then it stops talking to the acpi hardware,
preferring kvmclock clocksouce I guess.

So I expect hw-reduced acpi wouldn't make much of a difference.
Actually trying that isn't that high on my priority list.

There is bigger fish to fry, untangling the hw/i386/acpi-build.c
monster for starters, so building with ACPI=y + PCI=n works ...

cheers,
  Gerd