From: Tim Deegan <tim.deegan@xensource.com>
Date: Sat, 2 Sep 2006 11:11:54 +0000 (+0100)
Subject: [XEN] Fix mapping of p2m into monitor tables for external-mode guests.
X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~15668^2~22
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=9113a62c1b23ac5a242b0768ccf1561b0b738b65;p=xen.git

[XEN] Fix mapping of p2m into monitor tables for external-mode guests.
The previous code could map frame zero into the P2M table on PAE hosts.
Signed-off-by: Tim Deegan <Tim.Deegan@xensource.com>
---

diff --git a/xen/arch/x86/mm/shadow/multi.c b/xen/arch/x86/mm/shadow/multi.c
index e6210cc7fa..ace6a258f3 100644
--- a/xen/arch/x86/mm/shadow/multi.c
+++ b/xen/arch/x86/mm/shadow/multi.c
@@ -1792,8 +1792,10 @@ void sh_install_xen_entries_in_l2h(struct vcpu *v,
         for ( i = 0; i < MACHPHYS_MBYTES>>1; i++ )
         {
             sl2e[shadow_l2_table_offset(RO_MPT_VIRT_START) + i] =
-                shadow_l2e_from_mfn(_mfn(l3e_get_pfn(p2m[i])),
-                                    __PAGE_HYPERVISOR);
+                (l3e_get_flags(p2m[i]) & _PAGE_PRESENT)
+                ? shadow_l2e_from_mfn(_mfn(l3e_get_pfn(p2m[i])),
+                                      __PAGE_HYPERVISOR)
+                : shadow_l2e_empty();
         }
         sh_unmap_domain_page(p2m);
     }