[RFC,1/3] x86/mm: Change default value for suppress #VE in set_mem_access()

Commit Message

Adrian Pop April 5, 2017, 1:38 p.m. UTC

From: Vlad Ioan Topan <[e-mail]>

The default value for the "suppress #VE" bit set by set_mem_access()
currently depends on whether the call is made from the same domain (the
bit is set when called from another domain and cleared if called from
the same domain). This patch changes that behavior to inherit the old
suppress #VE bit value if it is already set and to set it to 1
otherwise, which is safer and more reliable.

Signed-off-by: Vlad Ioan Topan <[e-mail]>
---
 xen/arch/x86/mm/mem_access.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

Patch

diff --git a/xen/arch/x86/mm/mem_access.c b/xen/arch/x86/mm/mem_access.c
index 5adaf6df90..d0b0767855 100644
--- a/xen/arch/x86/mm/mem_access.c
+++ b/xen/arch/x86/mm/mem_access.c
@@ -273,8 +273,7 @@  int p2m_set_altp2m_mem_access(struct domain *d, struct p2m_domain *hp2m,
         }
     }
 
-    return ap2m->set_entry(ap2m, gfn_l, mfn, PAGE_ORDER_4K, t, a,
-                         (current->domain != d));
+    return ap2m->set_entry(ap2m, gfn_l, mfn, PAGE_ORDER_4K, t, a, -1);
 }
 
 static int set_mem_access(struct domain *d, struct p2m_domain *p2m,