From mboxrd@z Thu Jan 1 00:00:00 1970 From: Juergen Gross Subject: Re: using mapped vcpu_runstate_info in hvm guest Date: Wed, 20 Nov 2013 14:29:55 +0100 Message-ID: <528CB953.50205@ts.fujitsu.com> References: <5283839C.6090403@ts.fujitsu.com> <528CC2250200007800105058@nat28.tlf.novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta3.messagelabs.com ([195.245.230.39]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1Vj7qv-00087Y-Rf for xen-devel@lists.xenproject.org; Wed, 20 Nov 2013 13:29:58 +0000 In-Reply-To: <528CC2250200007800105058@nat28.tlf.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 Cc: xen-devel List-Id: xen-devel@lists.xenproject.org On 20.11.2013 14:07, Jan Beulich wrote: >>>> On 13.11.13 at 14:50, Juergen Gross wrote: >> I'm trying to obtain runstate information from the hypervisor in a hvm guest >> via VCPUOP_register_runstate_memory_area. This works, but the information is >> not completely suitable for a hvm guest: >> >> I can see the time summed up in the different states, but I'm not able to >> deduce the exact time the current vcpu has been running. I see the time when >> the last change to the running state happened (state_entry_time), but this >> time is the hypervisor system time obtained via NOW(). I can't see how to >> map this information to any time information available to the guest (e.g. >> the tsc value). > > __update_vcpu_system_time() specifically considers the case of > vTSC, so I'm not really clear what your problem here is. NOW() > (and hence state_entry_time) are in ns units, and the information > presented in struct vcpu_time_info should be sufficient to do the > necessary mapping (or else I can't see what's different in your > case from the usual PV or PVHVM one). > >> A solution would be to modify the runstate information mapped via >> VCPUOP_register_runstate_memory_area: it could contain state_entry_time >> rebased to the guests tsc. > > No, that one's defined to be matching up with vcpu_time_info's > system_time. Ah, okay. Then this was a mis-interpretation on my side. Thanks for the info. :-) I'll start another try based on this. Juergen -- Juergen Gross Principal Developer Operating Systems PBG PDG ES&S SWE OS6 Telephone: +49 (0) 89 62060 2932 Fujitsu e-mail: juergen.gross@ts.fujitsu.com Mies-van-der-Rohe-Str. 8 Internet: ts.fujitsu.com D-80807 Muenchen Company details: ts.fujitsu.com/imprint.html