[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] code read problems
Hi. On Fri, 2008-02-29 at 14:44 +0800, tgh wrote: > hi > I read checkpoint code > when checkpoint or migration ends,guestos continues processing by > returning back from hypercall of suspend, that is ,take_machine_down() > call the post_suspend() to continue ,is it right? > while in post_suspend(),pfn_to_mfn_frame_list_list[] is converted by > virt_to_mfn(),why do this convert? i could not find where it has been > converted,and why should it be converted back? No, not converted. Re-initialized. Please compare post_suspend() with the original initialization at system boot in setup_arch() (arch/x/kernel/setup-xen.c). It should come clear then. Observe that this is not canonicalization, because it is not the p2m, but a directory containing the *machine frames* *carrying* the p2m. Since the memory underlying the p2m has changed after resume, that directory needs a reset. > and in the xc_domain_restore()in the dom0,pagetable has been > uncanonicalized, which is coupled with canonicalization in > xc_domain_save(),is it ? ,and what is the reasons for > pfn_to_mfn_frame_list_list[] virt_to_mfn in post_suspend()? > could you help me Canonicalization forth and back is done by the migration code. Keeping the allocated frame list up to date is done by the domain itself. I do agree that this can be confusing indeed. hth, Daniel -- Daniel Stodden LRR - Lehrstuhl fÃr Rechnertechnik und Rechnerorganisation Institut fÃr Informatik der TU MÃnchen D-85748 Garching http://www.lrr.in.tum.de/~stodden mailto:stodden@xxxxxxxxxx PGP Fingerprint: F5A4 1575 4C56 E26A 0B33 3D80 457E 82AE B0D8 735B _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxxxxxxxx http://lists.xensource.com/xen-devel
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