I''m porting an OS to XEN 3.0 that uses PAE mode. It maps both virtual address space 0x00000000 and 0xC0000000 to the same physical address space, hence pgd slot 0 and pgd slot 3 point to the same middle page directory. It appears that XEN does not support this situation. The XEN error message I get when I try to pin the pgd is (XEN) DOM154: (file=mm.c, line=905) Failure in alloc_l3_table: entry 3 (XEN) DOM154: (file=mm.c, line=1550) Error while validating mfn d2a9 (pfn 10) for type 67ff0000: caf=80000003 taf=67ff0001 (XEN) DOM154: (file=mm.c, line=1780) Error while pinning mfn d2a9 If I set pgd slot 0 to 0 the pin succeeds. Does XEN support this "duplicate" mapping? Is this the right place to ask this question? Michael Levenhagen Sandia National Labs. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
> I''m porting an OS to XEN 3.0 that uses PAE mode. > It maps both virtual address space 0x00000000 and 0xC0000000 > to the same physical address space, hence pgd slot 0 and pgd > slot 3 point to the same middle page directory. It appears > that XEN does not support this situation. The XEN error > message I get when I try to pin the pgd is > > (XEN) DOM154: (file=mm.c, line=905) Failure in alloc_l3_table: entry 3 > (XEN) DOM154: (file=mm.c, line=1550) Error while validating > mfn d2a9 (pfn 10) for type 67ff0000: caf=80000003 taf=67ff0001 > (XEN) DOM154: (file=mm.c, line=1780) Error while pinning mfn d2a9 > > If I set pgd slot 0 to 0 the pin succeeds. > > Does XEN support this "duplicate" mapping?No. I imagine this is just in some start of day code in the OS that can easily be re-jigged? We have thought about supporting it as a slow-path operation, but it would lead to greater complexity in the type checking code, so probably not worth the effort.> Is this the right place to ask this question?xen-devel would be better. BTW: what''s the OS? Best, Ian _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
> > No. I imagine this is just in some start of day code in the OS that > can > easily be re-jigged?It''s not clear to me how invasive the changes would be. I don''t think it will be trivial.> > BTW: what''s the OS?The OS is OpenCatamount which is a derivative of the light weight OS that runs on Sandia''s ASCI Red and Red Storm. Thanks for the response. MIke _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users