From: Jan Beulich <jbeulich@suse.com>
Date: Tue, 1 Sep 2015 14:51:44 +0000 (+0200)
Subject: x86/mm: make {set,clear}_identity_p2m_mapping() work for PV guests
X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~2598
X-Git-Url: https://dgit.raspbian.org/%22http://www.example.com/cgi/success//%22http:/www.example.com/cgi/success/?a=commitdiff_plain;h=619ecf8400cbc1540d9f07c317a8e2d6782c5752;p=xen.git

x86/mm: make {set,clear}_identity_p2m_mapping() work for PV guests

Namely Dom0 suffers from commit 5ae03990c1 ("xen/vtd: create RMRR
mapping") having removed the creation of such mappings for non-
translated guests.

Reported-by: Malcolm Crossley <malcolm.crossley@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: George Dunlap <george.dunlap@citrix.com>
Release-acked-by: Wei Liu <wei.liu2@citrix.com>
---

diff --git a/xen/arch/x86/mm/p2m.c b/xen/arch/x86/mm/p2m.c
index 8fa918b827..b2726bd1e9 100644
--- a/xen/arch/x86/mm/p2m.c
+++ b/xen/arch/x86/mm/p2m.c
@@ -957,7 +957,11 @@ int set_identity_p2m_entry(struct domain *d, unsigned long gfn,
     int ret;
 
     if ( !paging_mode_translate(p2m->domain) )
-        return 0;
+    {
+        if ( !need_iommu(d) )
+            return 0;
+        return iommu_map_page(d, gfn, gfn, IOMMUF_readable|IOMMUF_writable);
+    }
 
     gfn_lock(p2m, gfn, 0);
 
@@ -1028,7 +1032,11 @@ int clear_identity_p2m_entry(struct domain *d, unsigned long gfn)
     int ret;
 
     if ( !paging_mode_translate(d) )
-        return 0;
+    {
+        if ( !need_iommu(d) )
+            return 0;
+        return iommu_unmap_page(d, gfn);
+    }
 
     gfn_lock(p2m, gfn, 0);