[Xen-devel] [PATCH 4 of 6] x86/mm/shadow: fix p2m/paging deadlock when updating shadow mode

[Andres Lagar-Cavilla <andres@xxxxxxxxxxxxxxxx>]

 xen/arch/x86/mm/shadow/common.c |  4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)


Signed-off-by: Andres Lagar-Cavilla <andres@xxxxxxxxxxxxxxxx>

diff -r 964c6cbad926 -r a7ca6ae73992 xen/arch/x86/mm/shadow/common.c
--- a/xen/arch/x86/mm/shadow/common.c
+++ b/xen/arch/x86/mm/shadow/common.c
@@ -2997,9 +2997,13 @@ static void sh_update_paging_modes(struc
 
 void shadow_update_paging_modes(struct vcpu *v)
 {
+    /* Avoid deadlock in shadow mode. When updating, we might need to resync an
+     * l1 and thus get_gfn on all the gfn's pointed to by the guest l1e pte's. 
*/
+    p2m_lock(p2m_get_hostp2m(v->domain));
     paging_lock(v->domain);
     sh_update_paging_modes(v);
     paging_unlock(v->domain);
+    p2m_unlock(p2m_get_hostp2m(v->domain));
 }
 
 /**************************************************************************/

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel