Xen uses lazy pinning of MM structures including the page table root and LDT,
which requires hooks at context creation and destruction time to maintain the
lazy list.
Patch-against: 2.6.13-rc5-mm1
Patch-keys: i386 mmu paravirt xen
Signed-off-by: Zachary Amsden <zach@xxxxxxxxxx>
Index: linux-2.6.13/include/asm-i386/mmu_context.h
===================================================================
--- linux-2.6.13.orig/include/asm-i386/mmu_context.h 2005-08-10 17:06:52.000000000 -0700
+++ linux-2.6.13/include/asm-i386/mmu_context.h 2005-08-10 17:11:40.000000000 -0700
@@ -6,6 +6,7 @@
#include <asm/atomic.h>
#include <asm/pgalloc.h>
#include <asm/tlbflush.h>
+#include <mach_mmu.h>
/*
* Used for LDT copy/destruction.
@@ -15,12 +16,14 @@
struct mm_struct * old_mm;
int retval = 0;
+ memset(&mm->context, 0, sizeof(mm->context));
init_MUTEX(&mm->context.sem);
- mm->context.size = 0;
old_mm = current->mm;
if (old_mm && unlikely(old_mm->context.size > 0)) {
retval = copy_ldt(&mm->context, &old_mm->context);
}
+ if (retval == 0)
+ add_lazy_mm(mm);
return retval;
}
@@ -31,6 +34,7 @@
{
if (unlikely(mm->context.size))
destroy_ldt(mm);
+ del_lazy_mm(mm);
}
static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
Index: linux-2.6.13/include/asm-i386/mach-default/mach_mmu.h
===================================================================
--- linux-2.6.13.orig/include/asm-i386/mach-default/mach_mmu.h 2005-08-10 17:11:40.000000000 -0700
+++ linux-2.6.13/include/asm-i386/mach-default/mach_mmu.h 2005-08-10 17:11:40.000000000 -0700
@@ -0,0 +1,10 @@
+#ifndef __ASM_MACH_MMU_H
+#define __ASM_MACH_MMU_H
+
+/*
+ * Stub hooks for lazy hypervisor pinning.
+ */
+#define add_lazy_mm(_mm)
+#define del_lazy_mm(_mm)
+
+#endif
