Hi! I''m a student and trying to port a small experimental operating system to xen. Currently I''m stuck when trying to set up the paging correctly. My problem is that I want to translate all machine frames belonging to the guest domain to physical page frames and back. The conversation from pfn to mfn seems to work well when using the mfn_list from the start_info_t. But when I try to translate the mfn back to pfn (using machine_to_phys_mapping from arch-x86_32.h which points to HYPERVISOR_VIRT_START) the guest domain crashes when I try to use specific array indeces (In the test setup these are 375-389, 2952-54 and possibly some more, also seems to depend at which index I''m starting (everything above index 2962 seems to work fine)). Could someone give me a hint what I''m missing? In the xen sparse tree include/asm-xen/asm-i386/page.h there is a small note in the pfn_to_mfn function: /* * The array access can fail (e.g., device space beyond end of RAM). * In such cases it doesn''t matter what we return (we return garbage), * but we must handle the fault without crashing! */ I guess this doesn''t apply to my situation as I''m only trying to translate mfn which belong to the guest domain, correct? Best Regards, Markus PS: Guess I will have some more questions soon :-) -- 10 GB Mailbox, 100 FreeSMS/Monat http://www.gmx.net/de/go/topmail +++ GMX - die erste Adresse fr Mail, Message, More +++ _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
m.rechberg@gmx.net
2006-Jan-22 22:46 UTC
Re: [Xen-devel] Crash when translating mfn to pfn
Hi! Forgot to mention: I''m using xen-3.0-testing (tar ball from the website, about two weeks ago). Best Regards, Markus -- Lust, ein paar Euro nebenbei zu verdienen? Ohne Kosten, ohne Risiko! Satte Provisionen fr GMX Partner: http://www.gmx.net/de/go/partner _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel