Xen devel - Mar 2008 - what''s the relationship between writable page and update_va_mapping?

Hi,

I''m running pv x86_64 linux under xen.

When I read the source code of the pv linux, I find that it use
update_va_mapping and mmu_update to modify the page table.

However, with the writable page table mechanism, why do we need those
explicit hypercalls to modify page table? In my understanding, when the
guest tries to modify the page table entry, such attempts will be captured
by "ptwr_do_page_fault" and then verified.

Please help to clarify my puzzle. :S

Thanks,
Weiming


_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xensource.com
http://lists.xensource.com/xen-devel