From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Vrabel Subject: Re: HVMlite ABI specification DRAFT B + implementation outline Date: Tue, 9 Feb 2016 16:17:28 +0000 Message-ID: <56BA1118.4000805@citrix.com> References: <56B8E66C.6060605@citrix.com> <56B9F69002000078000D012B@prv-mh.provo.novell.com> <56BA1EC302000078000D02A2@prv-mh.provo.novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta5.messagelabs.com ([195.245.231.135]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1aTAyt-0006c9-Ed for xen-devel@lists.xenproject.org; Tue, 09 Feb 2016 16:17:35 +0000 In-Reply-To: <56BA1EC302000078000D02A2@prv-mh.provo.novell.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Jan Beulich , Stefano Stabellini Cc: Wei Liu , Andrew Cooper , Tim Deegan , PaulDurrant , xen-devel , SamuelThibault , Boris Ostrovsky , roger.pau@citrix.com List-Id: xen-devel@lists.xenproject.org On 09/02/16 16:15, Jan Beulich wrote: >>>> On 09.02.16 at 16:06, wrote: >> On Tue, 9 Feb 2016, Jan Beulich wrote: >>> Will STAO be sufficient for everything that may need customization? >>> I'm particularly worried about processor related methods in DSDT or >>> SSDT, which - if we're really meaning to do as you say - would need >>> to be limited (or extended) to the number of vCPU-s Dom0 gets. >>> What's even less clear to me is how you mean to deal with P-, C-, >>> and (once supported) T-state management for CPUs which don't >>> have a vCPU equivalent in Dom0. >> >> It is possible to use the STAO to hide entire objects, including >> processors, from the DSDT, which should be good enough to prevent dom0 >> from calling any of the processor related methods you are referreing to. >> Then we can let Xen do cpuidle and cpufreq as it is already doing. >> >> Would that work? Or do we still need Dom0 to call any ACPI methods for >> power management? > > We want two things at once here, which afaict can't possibly work: > On one hand we want Dom0 to only see ACPI objects corresponding > to its own vCPU-s. Otoh we need Dom0 to see all objects, in order > to propagate respective information to Xen. Could dom0 query Xen for the machine ACPI tables via a hypercall? David