From mboxrd@z Thu Jan 1 00:00:00 1970 From: Philipp Hahn Subject: Re: [libvirt] =?utf-8?b?W1hlbi1kZXZlbF0gW0JVRywgCVBBVENILVJGQ10gbGli?= =?utf-8?q?virt_localtime_and_rtc=5Ftimeoffset_handling_in=09xen-sexpr/sxp?= =?utf-8?q?r/sxp?= Date: Wed, 11 Jan 2012 13:26:31 +0100 Message-ID: <201201111326.36514.hahn@univention.de> References: <201201111121.22236.hahn@univention.de> <1326282844.17210.190.camel@zakaz.uk.xensource.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============6961969359170421332==" Return-path: In-Reply-To: <1326282844.17210.190.camel@zakaz.uk.xensource.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: libvir-list-bounces@redhat.com Errors-To: libvir-list-bounces@redhat.com To: Ian Campbell Cc: "libvir-list@redhat.com" , "xen-devel@lists.xensource.com" , John Levon List-Id: xen-devel@lists.xenproject.org --===============6961969359170421332== Content-Type: multipart/signed; boundary="nextPart3555235.afP0mmBqrI"; protocol="application/pgp-signature"; micalg=pgp-sha1 Content-Transfer-Encoding: 7bit --nextPart3555235.afP0mmBqrI Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Content-Disposition: inline Hello Ian, Am Mittwoch 11 Januar 2012 12:54:04 schrieb Ian Campbell: > On Wed, 2012-01-11 at 10:20 +0000, Philipp Hahn wrote: > > I'm currently tracking a problem in libvirt regarding Xens handling of > > localtime and rtc_timeoffset. My current understanding (Xen-3.4.3 and > > Xen-4.1.2 under Linux) of Xend (the depcrecated Python one still used by > > libvirt) is as this: > > - for HV domains, the RTC gets setup to either UTC or localtime dependi= ng > > on "/domain/image/hvm/localtime" =C2=B1 "/domain/image/hvm/rtc_offset". > > Are those xenstore paths or a reference to a config file/sxp var? Those are XenStore paths. > I don't see the string "rtc_offset" anywhere under tools in > xen-unstable. I missed the "time", it's "rtc_timeoffset". Best search for RegExp=20 rtc.timeoffset, since so you'll find 'rtc/timeoffset' as well. =2E.. > They get PV time direct from the hypervisor which exposes the > hypervisor's wallclock to guests via the shared info. It is always UTC. > See > http://xenbits.xen.org/docs/unstable/hypercall/include,public,xen.h.html#= St >ruct_shared_info in particular the wc_* fields. Yes, I figured that out as well, but thanks for the link. > Classic-Xen kernels by default will take wallclock time from the shared > info for each gettimeofday but can be configured to be free-running > (that is the "independent_wallclock" mode). A lot of documentation still talks about /proc/xen/independent_wallclock,=20 which doesn't exist in 2.6.32 any more. I wish they would mention the Xen=20 version and Linux kerbel version they were using ... Thank you for your fast feedback. Sincerely Philipp Hahn =2D-=20 Philipp Hahn Open Source Software Engineer hahn@univention.de Univention GmbH Linux for Your Business fon: +49 421 22 232- 0 Mary-Somerville-Str.1 D-28359 Bremen fax: +49 421 22 232-99 http://www.univention.de/ --nextPart3555235.afP0mmBqrI Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) iEYEABECAAYFAk8Nf/cACgkQYPlgoZpUDjki0ACglLO2FDAi5GvciI+dKGnaJ/vM cJ8AnRZzYTTZtoNGRW9Xy0BKY+WvwT5Y =MpVs -----END PGP SIGNATURE----- --nextPart3555235.afP0mmBqrI-- --===============6961969359170421332== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline --===============6961969359170421332==--