[Xen-devel] [patch 10/20] XEN-paravirt: mm lifetime hooks

[Jeremy Fitzhardinge <jeremy@xxxxxxxx>]

Add hooks to allow a paravirt implementation to track the lifetime of
an mm.  Unfortunately dup_mmap and exit_mmap are in generic code, so
we need to #ifdef CONFIG_PARAVIRT.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xxxxxxxxxxxxx>
Cc: Chris Wright <chris@xxxxxxxxxxxx>
Cc: Zachary Amsden <zach@xxxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxx>
Cc: Rusty Russell <rusty@xxxxxxxxxxxxxxx>

--
 arch/i386/kernel/paravirt.c    |    4 ++++
 include/asm-i386/mmu_context.h |    8 ++++++--
 include/asm-i386/paravirt.h    |   38 ++++++++++++++++++++++++++++++++++++++
 kernel/fork.c                  |    3 +++
 mm/mmap.c                      |    4 ++++
 5 files changed, 55 insertions(+), 2 deletions(-)

===================================================================
--- a/arch/i386/kernel/paravirt.c
+++ b/arch/i386/kernel/paravirt.c
@@ -706,6 +706,10 @@ struct paravirt_ops paravirt_ops = {
        .irq_enable_sysexit = native_irq_enable_sysexit,
        .iret = native_iret,
 
+       .dup_mmap = (void *)native_nop,
+       .exit_mmap = (void *)native_nop,
+       .activate_mm = (void *)native_nop,
+
        .startup_ipi_hook = (void *)native_nop,
 };
 
===================================================================
--- a/include/asm-i386/mmu_context.h
+++ b/include/asm-i386/mmu_context.h
@@ -5,6 +5,7 @@
 #include <asm/atomic.h>
 #include <asm/pgalloc.h>
 #include <asm/tlbflush.h>
+#include <asm/paravirt.h>
 
 /*
  * Used for LDT copy/destruction.
@@ -65,7 +66,10 @@ static inline void switch_mm(struct mm_s
 #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
===================================================================
--- a/include/asm-i386/paravirt.h
+++ b/include/asm-i386/paravirt.h
@@ -126,6 +126,12 @@ struct paravirt_ops
        void (fastcall *io_delay)(void);
        void (*const_udelay)(unsigned long loops);
 
+       void (fastcall *activate_mm)(struct mm_struct *prev,
+                                    struct mm_struct *next);
+       void (fastcall *dup_mmap)(struct mm_struct *oldmm, 
+                                 struct mm_struct *mm);
+       void (fastcall *exit_mmap)(struct mm_struct *mm);
+
 #ifdef CONFIG_X86_LOCAL_APIC
        void (fastcall *apic_write)(unsigned long reg, unsigned long v);
        void (fastcall *apic_write_atomic)(unsigned long reg, unsigned long v);
@@ -429,6 +435,23 @@ static inline void startup_ipi_hook(int 
 }
 #endif
 
+static inline void paravirt_activate_mm(struct mm_struct *prev,
+                                       struct mm_struct *next)
+{
+       paravirt_ops.activate_mm(prev, next);
+}
+
+static inline void paravirt_dup_mmap(struct mm_struct *oldmm,
+                                    struct mm_struct *mm)
+{
+       paravirt_ops.dup_mmap(oldmm, mm);
+}
+
+static inline void paravirt_exit_mmap(struct mm_struct *mm)
+{
+       paravirt_ops.exit_mmap(mm);
+}
+
 #define __flush_tlb() paravirt_ops.flush_tlb_user()
 #define __flush_tlb_global() paravirt_ops.flush_tlb_kernel()
 #define __flush_tlb_single(addr) paravirt_ops.flush_tlb_single(addr)
@@ -673,5 +696,20 @@ static inline void paravirt_pagetable_se
        set_pgd(&base[0], base[USER_PTRS_PER_PGD]);
 #endif
 }
+
+static inline void paravirt_activate_mm(struct mm_struct *prev,
+                                       struct mm_struct *next)
+{
+}
+
+static inline void paravirt_dup_mmap(struct mm_struct *oldmm,
+                                    struct mm_struct *mm)
+{
+}
+
+static inline void paravirt_exit_mmap(struct mm_struct *mm)
+{
+}
+
 #endif /* CONFIG_PARAVIRT */
 #endif /* __ASM_PARAVIRT_H */
===================================================================
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -287,6 +287,9 @@ static inline int dup_mmap(struct mm_str
                if (retval)
                        goto out;
        }
+#ifdef CONFIG_PARAVIRT
+       paravirt_dup_mmap(oldmm, mm);
+#endif
        retval = 0;
 out:
        up_write(&mm->mmap_sem);
===================================================================
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1969,6 +1969,10 @@ void exit_mmap(struct mm_struct *mm)
        struct vm_area_struct *vma = mm->mmap;
        unsigned long nr_accounted = 0;
        unsigned long end;
+
+#ifdef CONFIG_PARAVIRT
+       paravirt_exit_mmap(mm);
+#endif
 
        lru_add_drain();
        flush_cache_mm(mm);

-- 


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel