From mboxrd@z Thu Jan  1 00:00:00 1970
From: PUCCETTI Armand <armand.puccetti@cea.fr>
Subject: idle_pg_tables?
Date: Wed, 30 Aug 2006 18:38:17 +0200
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In the paging mechanism of XEN what is the role of the variable 
'idle_pg_table'??

For a 4-levels paging it is defined as external in asm-x86/page.h, like this

extern root_pgentry_t <http://lxr.xensource.com/lxr/ident?a=x86_64;i=root_pgentry_t> idle_pg_table <http://lxr.xensource.com/lxr/ident?a=x86_64;i=idle_pg_table>[ROOT_PAGETABLE_ENTRIES <http://lxr.xensource.com/lxr/ident?a=x86_64;i=ROOT_PAGETABLE_ENTRIES>];
extern l2_pgentry_t <http://lxr.xensource.com/lxr/ident?a=x86_64;i=l2_pgentry_t>   idle_pg_table_l2 <http://lxr.xensource.com/lxr/ident?a=x86_64;i=idle_pg_table_l2>[ROOT_PAGETABLE_ENTRIES <http://lxr.xensource.com/lxr/ident?a=x86_64;i=ROOT_PAGETABLE_ENTRIES>];


but where is it initialised?
and why is there only such as idle table for levels 4 and 2?
thanks