Re: [PATCH RFC 10/13] xen: add ACPI bus to xen_nexus when running as Dom0

On Friday, February 14, 2014 5:38:15 am Roger Pau Monné wrote:
> On 08/02/14 22:50, John Baldwin wrote:
> > On Tuesday, December 24, 2013 12:20:59 PM Roger Pau Monne wrote:
> >> Also disable a couple of ACPI devices that are not usable under Dom0.
> > 
> > Hmm, setting debug.acpi.disabled in this way is a bit hacky.  It might
> > be fine however if there's no way for the user to set it before booting
> > the kernel (as opposed to haing the relevant drivers explicitly disable
> > themselves under Xen which I think would be cleaner, but would also
> > make your patch larger)
> 
> Thanks for the review, the user can pass parameters to FreeBSD when
> booted as Dom0, I just find it uncomfortable to force the user into
> always setting something on the command line in order to boot.

Can the user set debug.acpi.disabled?  If so, you are overriding their
setting which would be bad.

> What do you mean with "haing the relevant drivers explicitly disable
> themselves under Xen"? Adding a gate on every one of those devices like
> "if (xen_pv_domain()) return (ENXIO);" in the identify/probe routine
> seems even worse.

A check like this in probe() is what I had in mind, though I agree it's
not perfect.

-- 
John Baldwin