x86: 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.

[ Impact: fix Xen guest crash ]

Also-Bisected-by: Bryan Donlan <[email protected]>
Signed-off-by: Jeremy Fitzhardinge <[email protected]>
Cc: Xen-devel <[email protected]>
Cc: Linus Torvalds <[email protected]>
LKML-Reference: <4A032EEC[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>

diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index 9842b12124078f9795413a31e784dd96a1fc28a0..e25a78e1113a11f8b2c057508697d48b3d99b2af 100644 (file)
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -1794,6 +1794,11 @@ __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 */