Messages in this thread | | | Subject | Re: [Xen-devel] HPET enabled in BIOS, not presented as available_clocksource -- config, kernel code, &/or BIOS? | From | Andrew Cooper <> | Date | Sat, 13 May 2017 20:59:37 +0100 |
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On 13/05/2017 20:49, PGNet Dev wrote: > On 5/13/17 12:38 PM, Andrew Cooper wrote: >> What is the issue here? >> >> Xen owns (and may use) any HPETs in the system. They are purposefully >> unavailable to even dom0. > The issue is that, when booting to Xen, hpet is not advertised as an available clocksource, AND reports the hpet boot error pointed out by Randy. > > Following > > https://wiki.xen.org/wiki/Xen_power_management#HPET_as_broadcast_timer_source_.28clocksource.29_.3D > > there's discussion there re: 'if HPET is available / not missing'. > > It appears to be available only booting to non-Xen. > > What specific indication does one look for that Xen's using available hpet? >
Ok. Lack of a clocksource is to be expected.
The reason why the HPETs are unavailable is that dom0 is not a position to program them; dom0 doesn't know what Xen has set up in the IDT.
Use `xl dmesg` to get to the hypervisor dmesg log. You should see mention of the HPET in there if Xen has found it.
~Andrew
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