[PATCH v5 02/12] x86/xen: simplify flush_lazy_mmu()

[Kevin Brodsky <kevin.brodsky@xxxxxxx>]

arch_flush_lazy_mmu_mode() is called when outstanding batched
pgtable operations must be completed immediately. There should
however be no need to leave and re-enter lazy MMU completely. The
only part of that sequence that we really need is xen_mc_flush();
call it directly.

Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>
Reviewed-by: Ryan Roberts <ryan.roberts@xxxxxxx>
Reviewed-by: Juergen Gross <jgross@xxxxxxxx>
Signed-off-by: Kevin Brodsky <kevin.brodsky@xxxxxxx>
---
 arch/x86/xen/mmu_pv.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/arch/x86/xen/mmu_pv.c b/arch/x86/xen/mmu_pv.c
index 2a4a8deaf612..7a35c3393df4 100644
--- a/arch/x86/xen/mmu_pv.c
+++ b/arch/x86/xen/mmu_pv.c
@@ -2139,10 +2139,8 @@ static void xen_flush_lazy_mmu(void)
 {
        preempt_disable();
 
-       if (xen_get_lazy_mode() == XEN_LAZY_MMU) {
-               arch_leave_lazy_mmu_mode();
-               arch_enter_lazy_mmu_mode();
-       }
+       if (xen_get_lazy_mode() == XEN_LAZY_MMU)
+               xen_mc_flush();
 
        preempt_enable();
 }
-- 
2.51.2