[PATCH] x86: PARAVIRT: add hooks to intercept mm creation and destruction
Add hooks to allow a paravirt implementation to track the lifetime of
an mm. Paravirtualization requires three hooks, but only two are
needed in common code. They are:
arch_dup_mmap, which is called when a new mmap is created at fork
arch_exit_mmap, which is called when the last process reference to an
mm is dropped, which typically happens on exit and exec.
The third hook is activate_mm, which is called from the arch-specific
activate_mm() macro/function, and so doesn't need stub versions for
other architectures. It's called when an mm is first used.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: linux-arch@vger.kernel.org
Cc: James Bottomley <James.Bottomley@SteelEye.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
diff --git a/include/asm-i386/mmu_context.h b/include/asm-i386/mmu_context.h
index e6aa30f..8198d1c 100644
--- a/include/asm-i386/mmu_context.h
+++ b/include/asm-i386/mmu_context.h
@@ -5,6 +5,16 @@
#include <asm/atomic.h>
#include <asm/pgalloc.h>
#include <asm/tlbflush.h>
+#include <asm/paravirt.h>
+#ifndef CONFIG_PARAVIRT
+#include <asm-generic/mm_hooks.h>
+
+static inline void paravirt_activate_mm(struct mm_struct *prev,
+ struct mm_struct *next)
+{
+}
+#endif /* !CONFIG_PARAVIRT */
+
/*
* Used for LDT copy/destruction.
@@ -65,7 +75,10 @@
#define deactivate_mm(tsk, mm) \
asm("movl %0,%%gs": :"r" (0));
-#define activate_mm(prev, next) \
- switch_mm((prev),(next),NULL)
+#define activate_mm(prev, next) \
+ do { \
+ paravirt_activate_mm(prev, next); \
+ switch_mm((prev),(next),NULL); \
+ } while(0);
#endif