From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757155AbdEMTtg (ORCPT ); Sat, 13 May 2017 15:49:36 -0400 Received: from mail-pg0-f65.google.com ([74.125.83.65]:33346 "EHLO mail-pg0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755183AbdEMTtf (ORCPT ); Sat, 13 May 2017 15:49:35 -0400 Reply-To: pgnet.dev@gmail.com Subject: Re: [Xen-devel] HPET enabled in BIOS, not presented as available_clocksource -- config, kernel code, &/or BIOS? To: Andrew Cooper , Randy Dunlap , "linux-kernel@vger.kernel.org" , Clemens Ladisch , xen-devel@lists.xenproject.org References: <61d510e2-0353-ddf2-f63c-8a1688a6b6ed@gmail.com> <9ff8ca5a-727d-13c3-7c39-6383e00d2edf@infradead.org> <2c84903a-ab24-a073-378b-82fe6052e6ac@infradead.org> <927a6245-ae8b-ff4b-d668-a819b8351152@citrix.com> From: PGNet Dev Message-ID: <34c505d9-9dc6-8982-4875-74dedfc5e0d1@gmail.com> Date: Sat, 13 May 2017 12:49:32 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:53.0) Gecko/20100101 Thunderbird/53.0 MIME-Version: 1.0 In-Reply-To: <927a6245-ae8b-ff4b-d668-a819b8351152@citrix.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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?