[src/trunk]: src/sys/arch/xen Enable the map/unmap recursive mapping function...

[jym <jym%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/1fbff52b0ba6
branches:  trunk
changeset: 779881:1fbff52b0ba6
user:      jym <jym%NetBSD.org@localhost>
date:      Sun Jun 24 18:31:52 2012 +0000

description:
Enable the map/unmap recursive mapping functions for all Xen ports for
save/restore.

For an unknown reason (to me) Xen refuses to update VM translations
when the entry is pointing back to itself (which is precisely
what our recursive VM model does). So enable the functions that take
care of this, which will avoid all sort of memory corruption upon restore
leading domU to trample upon itself.

Save/restore works again for amd64. The occasional domU frontend corruption is
still present, but is harmless to dom0. Now we have a working shell and
ddb inside domU, that helps debugging a tiny bit.

XXX pull-up to -6.

diffstat:

 sys/arch/xen/include/xenpmap.h |   9 +++------
 sys/arch/xen/x86/xen_pmap.c    |  10 ++--------
 2 files changed, 5 insertions(+), 14 deletions(-)

diffs (74 lines):

diff -r 447fd56afccb -r 1fbff52b0ba6 sys/arch/xen/include/xenpmap.h
--- a/sys/arch/xen/include/xenpmap.h    Sun Jun 24 17:28:09 2012 +0000
+++ b/sys/arch/xen/include/xenpmap.h    Sun Jun 24 18:31:52 2012 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: xenpmap.h,v 1.34 2012/04/20 22:23:24 rmind Exp $       */
+/*     $NetBSD: xenpmap.h,v 1.35 2012/06/24 18:31:52 jym Exp $ */
 
 /*
  *
@@ -58,11 +58,8 @@
 
 void pmap_xen_resume(void);
 void pmap_xen_suspend(void);
-
-#ifdef PAE
-void   pmap_map_recursive_entries(void);
-void   pmap_unmap_recursive_entries(void);
-#endif /* PAE */
+void pmap_map_recursive_entries(void);
+void pmap_unmap_recursive_entries(void);
 
 #if defined(PAE) || defined(__x86_64__)
 void xen_kpm_sync(struct pmap *, int);
diff -r 447fd56afccb -r 1fbff52b0ba6 sys/arch/xen/x86/xen_pmap.c
--- a/sys/arch/xen/x86/xen_pmap.c       Sun Jun 24 17:28:09 2012 +0000
+++ b/sys/arch/xen/x86/xen_pmap.c       Sun Jun 24 18:31:52 2012 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: xen_pmap.c,v 1.21 2012/04/20 22:23:25 rmind Exp $      */
+/*     $NetBSD: xen_pmap.c,v 1.22 2012/06/24 18:31:53 jym Exp $        */
 
 /*
  * Copyright (c) 2007 Manuel Bouyer.
@@ -102,7 +102,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: xen_pmap.c,v 1.21 2012/04/20 22:23:25 rmind Exp $");
+__KERNEL_RCSID(0, "$NetBSD: xen_pmap.c,v 1.22 2012/06/24 18:31:53 jym Exp $");
 
 #include "opt_user_ldt.h"
 #include "opt_lockdebug.h"
@@ -241,9 +241,7 @@
 void
 pmap_xen_suspend(void)
 {
-#ifdef PAE
        pmap_unmap_recursive_entries();
-#endif
 
        xpq_flush_queue();
 }
@@ -251,14 +249,11 @@
 void
 pmap_xen_resume(void)
 {
-#ifdef PAE
        pmap_map_recursive_entries();
-#endif
 
        xpq_flush_queue();
 }
 
-#ifdef PAE
 /*
  * NetBSD uses L2 shadow pages to support PAE with Xen. However, Xen does not
  * handle them correctly during save/restore, leading to incorrect page
@@ -327,7 +322,6 @@
                    0);
        }
 }
-#endif /* PAE */
 
 #if defined(PAE) || defined(__x86_64__)