Re: xen.git branch reorg / crash with 2.6.30-rc3 pv_ops dom0

[Jeremy Fitzhardinge <jeremy@goop.org>]

Pasi Kärkkäinen wrote:
> And here we go:
> http://pasik.reaktio.net/xen/pv_ops-dom0-debug/pv_ops-dom0-bootlog-28-xen331-linux-2.6.30-rc3-next-crash-no-highpte.txt
>
> (XEN) d0:v0: unhandled page fault (ec=0003)
> (XEN) Pagetable walk from c1268000:
>   


Oh, look, we're not reserving the Xen pagetable, and this time we really 
should.  Does this work for you?

>From f26499cadfd057e4377e92ba680e16fa7bdf9422 Mon Sep 17 00:00:00 2001
From: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Date: Tue, 5 May 2009 13:08:42 -0700
Subject: [PATCH] xen/i386: reserve Xen pagetables

The Xen pagetables are no longer implicitly reserved as part of the other
i386_start_kernel reservations, so make sure we explicitly reserve them.
This prevents them from being released into the general kernel free page
pool and reused.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index 0e13477..801d042 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -1799,6 +1799,11 @@ __init pgd_t *xen_setup_kernel_pagetable(pgd_t *pgd,
 
 	pin_pagetable_pfn(MMUEXT_PIN_L3_TABLE, PFN_DOWN(__pa(swapper_pg_dir)));
 
+	reserve_early(__pa(xen_start_info->pt_base),
+		      __pa(xen_start_info->pt_base +
+			   xen_start_info->nr_pt_frames * PAGE_SIZE),
+		      "XEN PAGETABLES");
+
 	return swapper_pg_dir;
 }
 #endif	/* CONFIG_X86_64 */