[PATCH] i386: PARAVIRT: add flush_tlb_others paravirt_op

This patch adds a pv_op for flush_tlb_others.  Linux running on native
hardware uses cross-CPU IPIs to flush the TLB on any CPU which may
have a particular mm's pagetable entries cached in its TLB.  This is
inefficient in a paravirtualized environment, since the hypervisor
knows which real CPUs actually contain cached mappings, which may be a
small subset of a guest's VCPUs.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Andi Kleen <ak@suse.de>
diff --git a/include/asm-i386/paravirt.h b/include/asm-i386/paravirt.h
index 4b3d508..f880b06 100644
--- a/include/asm-i386/paravirt.h
+++ b/include/asm-i386/paravirt.h
@@ -15,6 +15,7 @@
 
 #ifndef __ASSEMBLY__
 #include <linux/types.h>
+#include <linux/cpumask.h>
 
 struct thread_struct;
 struct Xgt_desc_struct;
@@ -165,6 +166,8 @@
 	void (*flush_tlb_user)(void);
 	void (*flush_tlb_kernel)(void);
 	void (*flush_tlb_single)(unsigned long addr);
+	void (*flush_tlb_others)(const cpumask_t *cpus, struct mm_struct *mm,
+				 unsigned long va);
 
 	void (*map_pt_hook)(int type, pte_t *va, u32 pfn);
 
@@ -853,6 +856,12 @@
 	PVOP_VCALL1(flush_tlb_single, addr);
 }
 
+static inline void flush_tlb_others(cpumask_t cpumask, struct mm_struct *mm,
+				    unsigned long va)
+{
+	PVOP_VCALL3(flush_tlb_others, &cpumask, mm, va);
+}
+
 static inline void paravirt_map_pt_hook(int type, pte_t *va, u32 pfn)
 {
 	PVOP_VCALL3(map_pt_hook, type, va, pfn);