On Fri, Feb 14, 2025 at 02:39:17AM +0000, David Holland wrote:
> On Thu, Feb 13, 2025 at 10:52:30PM +0100, Manuel Bouyer wrote:
> > In the case of the VM the problem is not that it's bad, but that it's not
> > present (and, I guess, there is another RTC provised by the hypervisor in
> > this case). but AFAIK we don't have a way to know if the RTC is
> > present or not.
> >
> > Maybe a solution would be to not call startrtclock() at all in the VM
> > case. It's called from cpu_configure() and we're already checking
> > for VM_GUEST_XENPVH here.
>
> The hypervisor is a platform like any other, and we ought to be able
> to either probe the hardware or know what's there. Filling up driver
> code with "if (vm)" is not much better than filling it up with tests
> for specific motherboard models -- it might in some cases be the only
> alternative but it should be the last choice.
startrtclock() is called before drivers are attached AFAIK. But we can
move the check to cpu_configure()
>
> (also it should be specific to the broken hypervisor concerned and not
> applied to all hypervisors)
that's what VM_GUEST_* is for
--
Manuel Bouyer <bou...@antioche.eu.org>
NetBSD: 26 ans d'experience feront toujours la difference
--
