Is this currently possible? I''ve just got 2 Opteron 265''s that I''m about to put into a 4 way server with 8GB of RAM. -- ------------------------------------------------------ "Which exclusive club are: My mother, my ex, and Patricia Measham a member of? They''re all people who have spanked me!" -Rob "But those enemies of mine who did not want me to be king over them—bring them here and kill them in front of me." - Jesus (Luke 19:27) http://www.robhulme.com/ http://robhu.livejournal.com/ _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
> -----Original Message----- > From: xen-users-bounces@lists.xensource.com > [mailto:xen-users-bounces@lists.xensource.com] On Behalf Of > Robert Hulme > Sent: 06 April 2006 18:36 > To: Xen-users > Subject: [Xen-users] 32 bit guests on 64 bit xen0 ? > > Is this currently possible? > > I''ve just got 2 Opteron 265''s that I''m about to put into a 4 > way server with 8GB of RAM.No, your guest, in paravirtualized mode, will have to have the same bitness as your Xen kernel. There''s been some discussions about adding a shim-layer to support 32-bit para-virtualized kernel on top of 64-bit Xen, but so far no one has added any actual support for it. The fully virtualized support that AMD and Intel has added will support 32-bit guests on top of 64-bit Xen (but not the other way around). But that will need new processors from what you have now. -- Mats _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On Thu, Apr 06, 2006 at 06:36:16PM +0100, Robert Hulme wrote:> Is this currently possible?Sort-of. You can run 32-bit code on top of an AMD64/EM64T kernel, because the CPU itself is backwards compatible. It''s done just the same way as running a 32-bit userland on top of a 64-bit kernel in the non-Xen world. You can''t run a 32-bit kernel on a 64-bit dom0, though. - Matt _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
>> Is this currently possible? > >Sort-of. You can run 32-bit code on top of an AMD64/EM64T kernel, because >the CPU itself is backwards compatible. It''s done just the same way as >running a 32-bit userland on top of a 64-bit kernel in the non-Xen world. >You can''t run a 32-bit kernel on a 64-bit dom0, though.If you run a VT or Pacifica CPU then you can run unmodified 32-bit (and 32bit PAE) guests) as well as 64-bit guests. Right now you can, as Matt says, only run a paravirtualised (Xen-aware) 32-bit kernel on the 32-bit hypervisor, not on 64. Cheers, Mark _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On Thu, Apr 06, 2006 at 08:32:25PM +0200, Petersson, Mats wrote:> > -----Original Message----- > > From: xen-users-bounces@lists.xensource.com > > [mailto:xen-users-bounces@lists.xensource.com] On Behalf Of > > Robert Hulme > > Sent: 06 April 2006 18:36 > > To: Xen-users > > Subject: [Xen-users] 32 bit guests on 64 bit xen0 ? > > > > Is this currently possible? > > > > I''ve just got 2 Opteron 265''s that I''m about to put into a 4 > > way server with 8GB of RAM. > > No, your guest, in paravirtualized mode, will have to have the same > bitness as your Xen kernel. There''s been some discussions about adding a > shim-layer to support 32-bit para-virtualized kernel on top of 64-bit > Xen, but so far no one has added any actual support for it.In most cases its not really needed. Because x86_64 can execute 32bit code fine, I''ve done the following to have 32bit guests on 64bit system. * Grab a 32bit base image * Boot it with a 64bit out of body kernel (i.e. from the dom0 filesystem) * Fix up the package tool to force updated packages to i386 instead of the detected arch. This is pretty easy with Yum (Fedora), and URPMI (Mandriva) It''s "not quite" 32bit pure, but for most intents and purposes it should give you what you want. -Sean -- Sean Dague IBM Linux Technology Center email: japh@us.ibm.com Open Hypervisor Team alt: sldague@us.ibm.com _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users