xen: disable preempt for leave_lazy_mmu

xen_mc_flush() requires preemption to be disabled for its own sanity,
so disable it while we're flushing.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index 3f2d0fe5e6a8..0e572380413b 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -1812,8 +1812,10 @@ __init void xen_post_allocator_init(void)
 
 static void xen_leave_lazy_mmu(void)
 {
+        preempt_disable();
         xen_mc_flush();
         paravirt_leave_lazy_mmu();
+        preempt_enable();
 }
 
 const struct pv_mmu_ops xen_mmu_ops __initdata = {