Hi, in preparation to support live migration for BS2000 I''m testing my domU (HVM with PV-drivers) with xm save/restore. I''m running xen 4.0.2 (from SLES11 SP1). During xm save I see the following line in xend.log: [2011-10-25 13:25:25 31519] INFO (XendCheckpoint:484) Saving memory pages: iter 1 0%type fail: page 510 mfn 000011fe I added some diagnostic code to the hypervisor (in arch/x86/domctl.c) and found that the hypervisor believes gmfn 11fe of the domU is part of the xen heap. The problem is always reported for gmfn 11fe, regardless of the memory size of the domU: I tried 1, 2 and 8 GB. The memory page isn''t used for anything special in the domU, there is no problem accessing it or mapping it to dom0 before doing the xm save (or after xm save -c). When I try to restore the saved domain I can''t map gmfn 11fe of the domU any longer in dom0 (this was the first hint there is a problem at all). How can a domU memory page be part of the xen heap? Juergen -- Juergen Gross Principal Developer Operating Systems PDG ES&S SWE OS6 Telephone: +49 (0) 89 3222 2967 Fujitsu Technology Solutions e-mail: juergen.gross@ts.fujitsu.com Domagkstr. 28 Internet: ts.fujitsu.com D-80807 Muenchen Company details: ts.fujitsu.com/imprint.html _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
On 25/10/2011 14:15, "Juergen Gross" <juergen.gross@ts.fujitsu.com> wrote:> in preparation to support live migration for BS2000 I''m testing my domU (HVM > with PV-drivers) with xm save/restore. I''m running xen 4.0.2 (from SLES11 > SP1). > > During xm save I see the following line in xend.log: > > [2011-10-25 13:25:25 31519] INFO (XendCheckpoint:484) Saving memory pages: > iter 1 0%type fail: page 510 mfn 000011fe > > I added some diagnostic code to the hypervisor (in arch/x86/domctl.c) and > found > that the hypervisor believes gmfn 11fe of the domU is part of the xen heap. > > The problem is always reported for gmfn 11fe, regardless of the memory size of > the domU: I tried 1, 2 and 8 GB. The memory page isn''t used for anything > special in the domU, there is no problem accessing it or mapping it to dom0 > before doing the xm save (or after xm save -c). > > When I try to restore the saved domain I can''t map gmfn 11fe of the domU any > longer in dom0 (this was the first hint there is a problem at all). > > How can a domU memory page be part of the xen heap?It could be the domain''s shared-info page, or one of its grant-table pages. It doesn''t make sense to save/restore such pages -- they get reconstructed appropriately on the receiving end, by the toolstack and/or by the domain itself when it resumes execution. -- Keir _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
On 10/25/2011 03:32 PM, Keir Fraser wrote:> On 25/10/2011 14:15, "Juergen Gross"<juergen.gross@ts.fujitsu.com> wrote: > >> in preparation to support live migration for BS2000 I''m testing my domU (HVM >> with PV-drivers) with xm save/restore. I''m running xen 4.0.2 (from SLES11 >> SP1). >> >> During xm save I see the following line in xend.log: >> >> [2011-10-25 13:25:25 31519] INFO (XendCheckpoint:484) Saving memory pages: >> iter 1 0%type fail: page 510 mfn 000011fe >> >> I added some diagnostic code to the hypervisor (in arch/x86/domctl.c) and >> found >> that the hypervisor believes gmfn 11fe of the domU is part of the xen heap. >> >> The problem is always reported for gmfn 11fe, regardless of the memory size of >> the domU: I tried 1, 2 and 8 GB. The memory page isn''t used for anything >> special in the domU, there is no problem accessing it or mapping it to dom0 >> before doing the xm save (or after xm save -c). >> >> When I try to restore the saved domain I can''t map gmfn 11fe of the domU any >> longer in dom0 (this was the first hint there is a problem at all). >> >> How can a domU memory page be part of the xen heap? > It could be the domain''s shared-info page, or one of its grant-table pages. > It doesn''t make sense to save/restore such pages -- they get reconstructed > appropriately on the receiving end, by the toolstack and/or by the domain > itself when it resumes execution.Thanks! It IS a grant-table page. Juergen -- Juergen Gross Principal Developer Operating Systems PDG ES&S SWE OS6 Telephone: +49 (0) 89 3222 2967 Fujitsu Technology Solutions e-mail: juergen.gross@ts.fujitsu.com Domagkstr. 28 Internet: ts.fujitsu.com D-80807 Muenchen Company details: ts.fujitsu.com/imprint.html _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel