Hi, We have dual CPU Quad-Core Xeons (64 bit HVM) machine. I am wondering if some one else have tried to deploy 32bit domU on 64 bit. I tried with Xen 3.0.3 but it didn''t work. I remember some one mentioning on the mailing list that this functionality would be there in Xen 3.0.5. I guess 3.0.5 would be out in few weeks, but it would be great if some one could point me to the code branch in Xen''s source repository which have got this functionality implemented? Many thanks, Omer ---------------------------------------------------------- CERN – European Organization for Nuclear Research, IT Department, CH-1211 Geneva 23, Switzerland Phone: +41 (0) 22 767 7996 Fax: +41 (0) 22 766 8683 E-mail : Omer.Khalid@cern.ch Homepage: http://cern.ch/Omer.Khalid _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
> -----Original Message----- > From: okhalid.cern@gmail.com [mailto:okhalid.cern@gmail.com] > On Behalf Of Omer Khalid > Sent: 10 May 2007 10:16 > To: xen-users@lists.xensource.com > Cc: Petersson, Mats > Subject: 32bit domU in 64 bit dom0 > > > Hi, > > We have dual CPU Quad-Core Xeons (64 bit HVM) machine. I am > wondering if some one else have tried to deploy 32bit domU on > 64 bit. I tried with Xen 3.0.3 but it didn''t work. I remember > some one mentioning on the mailing list that this > functionality would be there in Xen 3.0.5.32-bit PAE Para-virtual domains will need 3.1.0 (the version formerly known as 3.0.5) to work correctly, yes. HVM domains should work straight away in 3.0.3, but there may of course be OTHER things that make this not work, if that''s what you''ve tried.> > I guess 3.0.5 would be out in few weeks, but it would be > great if some one could point me to the code branch in Xen''s > source repository which have got this functionality implemented?There''s rc10 at the moment in http://xenbits.xensource.com/xen-3.1-testing.hg I''m not sure how long before 3.1.0 comes out, but it should be fairly soon. If you want to use this feature, I would recommend that you get the latest version of 3.1-testing and check it out, just in case there''s some minor bugs that can be fixed before the release! -- Mats> > ---------------------------------------------------------- > CERN - European Organization for Nuclear > Research, IT Department, CH-1211 > Geneva 23, Switzerland > > Phone: +41 (0) 22 767 7996 > Fax: +41 (0) 22 766 8683 > E-mail : Omer.Khalid@cern.ch > Homepage: http://cern.ch/Omer.Khalid >_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
> We have dual CPU Quad-Core Xeons (64 bit HVM) machine. I am wondering if > some one else have tried to deploy 32bit domU on 64 bit. I tried with Xen > 3.0.3 but it didn''t work. I remember some one mentioning on the mailing > list that this functionality would be there in Xen 3.0.5.This may work for HVM domains with your current install (Linux is more likely to work than Windows), although I''m not sure if it''s officially supported. HVM on 64-bit has (as far as I know) always supported 32-bit as well as 64-bit guests.> I guess 3.0.5 would be out in few weeks, but it would be great if some one > could point me to the code branch in Xen''s source repository which have got > this functionality implemented?3.0.5 will support running 32-bit PAE PV guests on a 64-bit Xen, as well as the usual combination of 32-bit non-PAE, 32-bit PAE and 64-bit HVM guests. The only kind of guest it doesn''t support is 32-bit non-PAE guests[*] Cheers, Mark [*] I think it''s a shame we don''t support 32-bit non-PAE guests on 64-bit Xen. I''m told most of the machinery should be there already. As far as I''m aware, only the Linux port supports PAE, although I may be behind on this information. -- Dave: Just a question. What use is a unicyle with no seat? And no pedals! Mark: To answer a question with a question: What use is a skateboard? Dave: Skateboards have wheels. Mark: My wheel has a wheel! _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Mark Williamson wrote:> [*] I think it''s a shame we don''t support 32-bit non-PAE > guests on 64-bit Xen. > I''m told most of the machinery should be there already. As > far as I''m aware, > only the Linux port supports PAE, although I may be behind on this > information.The main reason for this is that the 64-bit hypervisor uses 4-level pagetables, and 32-bit PAE uses 3-level page-tables. Both 4- and 3-level page-tables use 64-bit entries in the table. However, 32-bit non-PAE uses 32-bit page-table entries. I don''t think it''s quite so easy to switch to 32-bit non-PAE page-tables when running a 64-bit hypervisor - it''s probably POSSIBLE, but it makes life a lot harder. Since we''re talking about PV-guests in the first place, it''s not too much to ask that the guest is compiled for PAE mode rather than non-PAE - it would be different if it was HVM guest that don''t necessarily have easy access to source-code... -- Mats _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
> > [*] I think it''s a shame we don''t support 32-bit non-PAE > > guests on 64-bit Xen. > > I''m told most of the machinery should be there already. As > > far as I''m aware, > > only the Linux port supports PAE, although I may be behind on this > > information. > > The main reason for this is that the 64-bit hypervisor uses 4-level > pagetables, and 32-bit PAE uses 3-level page-tables. Both 4- and 3-level > page-tables use 64-bit entries in the table. However, 32-bit non-PAE > uses 32-bit page-table entries. I don''t think it''s quite so easy to > switch to 32-bit non-PAE page-tables when running a 64-bit hypervisor - > it''s probably POSSIBLE, but it makes life a lot harder.Yep, AFAIK the 32-bit PAE page tables are just hooked onto the host''s 4-level page table (with Xen being mapped above the guest''s accessible memory using an entry in the PUD). Well, the fix would probably be to use shadow page tables - I''ve heard this suggested a few times as the means by which this would be supported if there was sufficient motivation (which there isn''t ... yet, at least). Shadow pagetables for 32-on-64 already sort-of work since they''re supported for HVM. Code would need to be added to handle 32-bit PV guests, but beyond that I don''t think there''s much required to make non-PAE guests work. (?)> Since we''re > talking about PV-guests in the first place, it''s not too much to ask > that the guest is compiled for PAE mode rather than non-PAE - it would > be different if it was HVM guest that don''t necessarily have easy access > to source-code...Well, yes and no. Some folks may want to migrate legacy guests from a 32-bit non-PAE host - that was our default install for a long time. Also, I suspect the NetBSD, Plan9 and FreeBSD guest ports don''t all support PAE (if any of them do). non-PAE 32-bit on the 64-bit hypervisor is the one thing keeping it from being able to "do anything" and virtualise a superset of the guests supported by other hypervisors. Not critical, though. Cheers, Mark -- Dave: Just a question. What use is a unicyle with no seat? And no pedals! Mark: To answer a question with a question: What use is a skateboard? Dave: Skateboards have wheels. Mark: My wheel has a wheel! _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Hi Mats, Petersson, Mats wrote:>> Hi, >> >> We have dual CPU Quad-Core Xeons (64 bit HVM) machine. I am >> wondering if some one else have tried to deploy 32bit domU on >> 64 bit. I tried with Xen 3.0.3 but it didn''t work. I remember >> some one mentioning on the mailing list that this >> functionality would be there in Xen 3.0.5. > > 32-bit PAE Para-virtual domains will need 3.1.0 (the version formerly > known as 3.0.5) to work correctly, yes. > > HVM domains should work straight away in 3.0.3, but there may of course > be OTHER things that make this not work, if that''s what you''ve tried. > >> I guess 3.0.5 would be out in few weeks, but it would be >> great if some one could point me to the code branch in Xen''s >> source repository which have got this functionality implemented? > > There''s rc10 at the moment in > http://xenbits.xensource.com/xen-3.1-testing.hg>> I''m not sure how long before 3.1.0 comes out, but it should be fairly > soon. If you want to use this feature, I would recommend that you get > the latest version of 3.1-testing and check it out, just in case there''s > some minor bugs that can be fixed before the release!I checked 3.1 out from the repo, compiled and can confirm that three 32 bit PV DomUs in 64 bit Dom0 survived overnight stress tests. Hosts: Dell PowerEdge 2950 with dual CPU Dual-Core Xeons 5130. Next test will be with dual CPU Quad-Core Xeons E5320 (but I think there will be no problems). Thanks for pointing this out and great job you are doing! Regards, Konstantin Skaburskas --------------------------------------------------- CERN - European Organization for Nuclear Research IT Department. CERN CH-1211, Genève 23, Switzerland Phone: +41 (0) 22 76 76002 Fax: +41 (0) 22 76 74900 E-mail: Konstantin.Skaburskas@cern.ch ---------------------------------------------------> -- > Mats >> ---------------------------------------------------------- >> CERN - European Organization for Nuclear >> Research, IT Department, CH-1211 >> Geneva 23, Switzerland >> >> Phone: +41 (0) 22 767 7996 >> Fax: +41 (0) 22 766 8683 >> E-mail : Omer.Khalid@cern.ch >> Homepage: http://cern.ch/Omer.Khalid >> > > > > _______________________________________________ > Xen-users mailing list > Xen-users@lists.xensource.com > http://lists.xensource.com/xen-users_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users