Re: [PATCH 1/6] mmu_notifier: add event information to address invalidation v6

[Oded Gabbay <oded.gabbay@amd.com>]

On 01/06/2015 12:44 AM, j.glisse@gmail.com wrote:
> From: Jérôme Glisse <jglisse@redhat.com>
> 
> The event information will be useful for new user of mmu_notifier API.
> The event argument differentiate between a vma disappearing, a page
> being write protected or simply a page being unmaped. This allow new
> user to take different path for different event for instance on unmap
> the resource used to track a vma are still valid and should stay around.
> While if the event is saying that a vma is being destroy it means that any
> resources used to track this vma can be free.
> 
> Changed since v1:
>   - renamed action into event (updated commit message too).
>   - simplified the event names and clarified their usage
>     also documenting what exceptation the listener can have in
>     respect to each event.
> 
> Changed since v2:
>   - Avoid crazy name.
>   - Do not move code that do not need to move.
> 
> Changed since v3:
>   - Separate hugue page split from mlock/munlock and softdirty.
> 
> Changed since v4:
>   - Rebase (no other changes).
> 
> Changed since v5:
>   - Typo fix.
>   - Changed zap_page_range from MMU_MUNMAP to MMU_MIGRATE to reflect the
>     fact that the address range is still valid just the page backing it
>     are no longer.
> 
> Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
> Reviewed-by: Rik van Riel <riel@redhat.com>
> ---
>  drivers/gpu/drm/i915/i915_gem_userptr.c |   3 +-
>  drivers/gpu/drm/radeon/radeon_mn.c      |   3 +-
>  drivers/infiniband/core/umem_odp.c      |   9 ++-
>  drivers/iommu/amd_iommu_v2.c            |   3 +-
>  drivers/misc/sgi-gru/grutlbpurge.c      |   9 ++-
>  drivers/xen/gntdev.c                    |   9 ++-
>  fs/proc/task_mmu.c                      |   6 +-
>  include/linux/mmu_notifier.h            | 131 ++++++++++++++++++++++++++------
>  kernel/events/uprobes.c                 |  10 ++-
>  mm/filemap_xip.c                        |   2 +-
>  mm/huge_memory.c                        |  39 ++++++----
>  mm/hugetlb.c                            |  23 +++---
>  mm/ksm.c                                |  18 +++--
>  mm/madvise.c                            |   4 +-
>  mm/memory.c                             |  27 ++++---
>  mm/migrate.c                            |   9 ++-
>  mm/mmu_notifier.c                       |  28 ++++---
>  mm/mprotect.c                           |   6 +-
>  mm/mremap.c                             |   6 +-
>  mm/rmap.c                               |  24 ++++--
>  virt/kvm/kvm_main.c                     |  12 ++-
>  21 files changed, 274 insertions(+), 107 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_gem_userptr.c b/drivers/gpu/drm/i915/i915_gem_userptr.c
> index d182058..20dbd26 100644
> --- a/drivers/gpu/drm/i915/i915_gem_userptr.c
> +++ b/drivers/gpu/drm/i915/i915_gem_userptr.c
> @@ -129,7 +129,8 @@ restart:
>  static void i915_gem_userptr_mn_invalidate_range_start(struct mmu_notifier *_mn,
>  						       struct mm_struct *mm,
>  						       unsigned long start,
> -						       unsigned long end)
> +						       unsigned long end,
> +						       enum mmu_event event)
>  {
>  	struct i915_mmu_notifier *mn = container_of(_mn, struct i915_mmu_notifier, mn);
>  	struct interval_tree_node *it = NULL;
> diff --git a/drivers/gpu/drm/radeon/radeon_mn.c b/drivers/gpu/drm/radeon/radeon_mn.c
> index a69bd44..daf53d3 100644
> --- a/drivers/gpu/drm/radeon/radeon_mn.c
> +++ b/drivers/gpu/drm/radeon/radeon_mn.c
> @@ -109,7 +109,8 @@ static void radeon_mn_release(struct mmu_notifier *mn,
>  static void radeon_mn_invalidate_range_start(struct mmu_notifier *mn,
>  					     struct mm_struct *mm,
>  					     unsigned long start,
> -					     unsigned long end)
> +					     unsigned long end,
> +					     enum mmu_event event)
>  {
>  	struct radeon_mn *rmn = container_of(mn, struct radeon_mn, mn);
>  	struct interval_tree_node *it;
> diff --git a/drivers/infiniband/core/umem_odp.c b/drivers/infiniband/core/umem_odp.c
> index 6095872..bc36e8c 100644
> --- a/drivers/infiniband/core/umem_odp.c
> +++ b/drivers/infiniband/core/umem_odp.c
> @@ -165,7 +165,8 @@ static int invalidate_page_trampoline(struct ib_umem *item, u64 start,
>  
>  static void ib_umem_notifier_invalidate_page(struct mmu_notifier *mn,
>  					     struct mm_struct *mm,
> -					     unsigned long address)
> +					     unsigned long address,
> +					     enum mmu_event event)
>  {
>  	struct ib_ucontext *context = container_of(mn, struct ib_ucontext, mn);
>  
> @@ -192,7 +193,8 @@ static int invalidate_range_start_trampoline(struct ib_umem *item, u64 start,
>  static void ib_umem_notifier_invalidate_range_start(struct mmu_notifier *mn,
>  						    struct mm_struct *mm,
>  						    unsigned long start,
> -						    unsigned long end)
> +						    unsigned long end,
> +						    enum mmu_event event)
>  {
>  	struct ib_ucontext *context = container_of(mn, struct ib_ucontext, mn);
>  
> @@ -217,7 +219,8 @@ static int invalidate_range_end_trampoline(struct ib_umem *item, u64 start,
>  static void ib_umem_notifier_invalidate_range_end(struct mmu_notifier *mn,
>  						  struct mm_struct *mm,
>  						  unsigned long start,
> -						  unsigned long end)
> +						  unsigned long end,
> +						  enum mmu_event event)
>  {
>  	struct ib_ucontext *context = container_of(mn, struct ib_ucontext, mn);
>  
> diff --git a/drivers/iommu/amd_iommu_v2.c b/drivers/iommu/amd_iommu_v2.c
> index 90f70d0..31acb07 100644
> --- a/drivers/iommu/amd_iommu_v2.c
> +++ b/drivers/iommu/amd_iommu_v2.c
> @@ -402,7 +402,8 @@ static int mn_clear_flush_young(struct mmu_notifier *mn,
>  
>  static void mn_invalidate_page(struct mmu_notifier *mn,
>  			       struct mm_struct *mm,
> -			       unsigned long address)
> +			       unsigned long address,
> +			       enum mmu_event event)
>  {
>  	__mn_flush_page(mn, address);
>  }
> diff --git a/drivers/misc/sgi-gru/grutlbpurge.c b/drivers/misc/sgi-gru/grutlbpurge.c
> index 2129274..e67fed1 100644
> --- a/drivers/misc/sgi-gru/grutlbpurge.c
> +++ b/drivers/misc/sgi-gru/grutlbpurge.c
> @@ -221,7 +221,8 @@ void gru_flush_all_tlb(struct gru_state *gru)
>   */
>  static void gru_invalidate_range_start(struct mmu_notifier *mn,
>  				       struct mm_struct *mm,
> -				       unsigned long start, unsigned long end)
> +				       unsigned long start, unsigned long end,
> +				       enum mmu_event event)
>  {
>  	struct gru_mm_struct *gms = container_of(mn, struct gru_mm_struct,
>  						 ms_notifier);
> @@ -235,7 +236,8 @@ static void gru_invalidate_range_start(struct mmu_notifier *mn,
>  
>  static void gru_invalidate_range_end(struct mmu_notifier *mn,
>  				     struct mm_struct *mm, unsigned long start,
> -				     unsigned long end)
> +				     unsigned long end,
> +				     enum mmu_event event)
>  {
>  	struct gru_mm_struct *gms = container_of(mn, struct gru_mm_struct,
>  						 ms_notifier);
> @@ -248,7 +250,8 @@ static void gru_invalidate_range_end(struct mmu_notifier *mn,
>  }
>  
>  static void gru_invalidate_page(struct mmu_notifier *mn, struct mm_struct *mm,
> -				unsigned long address)
> +				unsigned long address,
> +				enum mmu_event event)
>  {
>  	struct gru_mm_struct *gms = container_of(mn, struct gru_mm_struct,
>  						 ms_notifier);
> diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
> index 073b4a1..fe9da94 100644
> --- a/drivers/xen/gntdev.c
> +++ b/drivers/xen/gntdev.c
> @@ -428,7 +428,9 @@ static void unmap_if_in_range(struct grant_map *map,
>  
>  static void mn_invl_range_start(struct mmu_notifier *mn,
>  				struct mm_struct *mm,
> -				unsigned long start, unsigned long end)
> +				unsigned long start,
> +				unsigned long end,
> +				enum mmu_event event)
>  {
>  	struct gntdev_priv *priv = container_of(mn, struct gntdev_priv, mn);
>  	struct grant_map *map;
> @@ -445,9 +447,10 @@ static void mn_invl_range_start(struct mmu_notifier *mn,
>  
>  static void mn_invl_page(struct mmu_notifier *mn,
>  			 struct mm_struct *mm,
> -			 unsigned long address)
> +			 unsigned long address,
> +			 enum mmu_event event)
>  {
> -	mn_invl_range_start(mn, mm, address, address + PAGE_SIZE);
> +	mn_invl_range_start(mn, mm, address, address + PAGE_SIZE, event);
>  }
>  
>  static void mn_release(struct mmu_notifier *mn,
> diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
> index 246eae8..8a79a74 100644
> --- a/fs/proc/task_mmu.c
> +++ b/fs/proc/task_mmu.c
> @@ -875,7 +875,8 @@ static ssize_t clear_refs_write(struct file *file, const char __user *buf,
>  				downgrade_write(&mm->mmap_sem);
>  				break;
>  			}
> -			mmu_notifier_invalidate_range_start(mm, 0, -1);
> +			mmu_notifier_invalidate_range_start(mm, 0,
> +							    -1, MMU_ISDIRTY);
>  		}
>  		for (vma = mm->mmap; vma; vma = vma->vm_next) {
>  			cp.vma = vma;
> @@ -900,7 +901,8 @@ static ssize_t clear_refs_write(struct file *file, const char __user *buf,
>  					&clear_refs_walk);
>  		}
>  		if (type == CLEAR_REFS_SOFT_DIRTY)
> -			mmu_notifier_invalidate_range_end(mm, 0, -1);
> +			mmu_notifier_invalidate_range_end(mm, 0,
> +							  -1, MMU_ISDIRTY);
>  		flush_tlb_mm(mm);
>  		up_read(&mm->mmap_sem);
>  		mmput(mm);
> diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h
> index 95243d2..ac2a121 100644
> --- a/include/linux/mmu_notifier.h
> +++ b/include/linux/mmu_notifier.h
> @@ -9,6 +9,66 @@
>  struct mmu_notifier;
>  struct mmu_notifier_ops;
>  
> +/* MMU Events report fine-grained information to the callback routine, allowing
> + * the event listener to make a more informed decision as to what action to
> + * take. The event types are:
> + *
> + *   - MMU_HSPLIT huge page split, the memory is the same only the page table
> + *     structure is updated (level added or removed).
> + *
> + *   - MMU_ISDIRTY need to update the dirty bit of the page table so proper
> + *     dirty accounting can happen.
> + *
> + *   - MMU_MIGRATE: memory is migrating from one page to another, thus all write
> + *     access must stop after invalidate_range_start callback returns.
> + *     Furthermore, no read access should be allowed either, as a new page can
> + *     be remapped with write access before the invalidate_range_end callback
> + *     happens and thus any read access to old page might read stale data. There
> + *     are several sources for this event, including:
> + *
> + *         - A page moving to swap (various reasons, including page reclaim),
> + *         - An mremap syscall,
> + *         - migration for NUMA reasons,
> + *         - balancing the memory pool,
> + *         - write fault on COW page,
> + *         - and more that are not listed here.
> + *
> + *   - MMU_MPROT: memory access protection is changing. Refer to the vma to get
> + *     the new access protection. All memory access are still valid until the
> + *     invalidate_range_end callback.
> + *
> + *   - MMU_MUNLOCK: unlock memory. Content of page table stays the same but
> + *     page are unlocked.
> + *
> + *   - MMU_MUNMAP: the range is being unmapped (outcome of a munmap syscall or
> + *     process destruction). However, access is still allowed, up until the
> + *     invalidate_range_free_pages callback. This also implies that secondary
> + *     page table can be trimmed, because the address range is no longer valid.
> + *
> + *   - MMU_WRITE_BACK: memory is being written back to disk, all write accesses
> + *     must stop after invalidate_range_start callback returns. Read access are
> + *     still allowed.
> + *
> + *   - MMU_WRITE_PROTECT: memory is being write protected (ie should be mapped
> + *     read only no matter what the vma memory protection allows). All write
> + *     accesses must stop after invalidate_range_start callback returns. Read
> + *     access are still allowed.
> + *
> + * If in doubt when adding a new notifier caller, please use MMU_MIGRATE,
> + * because it will always lead to reasonable behavior, but will not allow the
> + * listener a chance to optimize its events.
> + */
> +enum mmu_event {
> +	MMU_HSPLIT = 0,
> +	MMU_ISDIRTY,
> +	MMU_MIGRATE,
> +	MMU_MPROT,
> +	MMU_MUNLOCK,
> +	MMU_MUNMAP,
> +	MMU_WRITE_BACK,
> +	MMU_WRITE_PROTECT,
> +};
> +
>  #ifdef CONFIG_MMU_NOTIFIER
>  
>  /*
> @@ -82,7 +142,8 @@ struct mmu_notifier_ops {
>  	void (*change_pte)(struct mmu_notifier *mn,
>  			   struct mm_struct *mm,
>  			   unsigned long address,
> -			   pte_t pte);
> +			   pte_t pte,
> +			   enum mmu_event event);
>  
>  	/*
>  	 * Before this is invoked any secondary MMU is still ok to
> @@ -93,7 +154,8 @@ struct mmu_notifier_ops {
>  	 */
>  	void (*invalidate_page)(struct mmu_notifier *mn,
>  				struct mm_struct *mm,
> -				unsigned long address);
> +				unsigned long address,
> +				enum mmu_event event);
>  
>  	/*
>  	 * invalidate_range_start() and invalidate_range_end() must be
> @@ -140,10 +202,14 @@ struct mmu_notifier_ops {
>  	 */
>  	void (*invalidate_range_start)(struct mmu_notifier *mn,
>  				       struct mm_struct *mm,
> -				       unsigned long start, unsigned long end);
> +				       unsigned long start,
> +				       unsigned long end,
> +				       enum mmu_event event);
>  	void (*invalidate_range_end)(struct mmu_notifier *mn,
>  				     struct mm_struct *mm,
> -				     unsigned long start, unsigned long end);
> +				     unsigned long start,
> +				     unsigned long end,
> +				     enum mmu_event event);
>  
>  	/*
>  	 * invalidate_range() is either called between
> @@ -206,13 +272,20 @@ extern int __mmu_notifier_clear_flush_young(struct mm_struct *mm,
>  extern int __mmu_notifier_test_young(struct mm_struct *mm,
>  				     unsigned long address);
>  extern void __mmu_notifier_change_pte(struct mm_struct *mm,
> -				      unsigned long address, pte_t pte);
> +				      unsigned long address,
> +				      pte_t pte,
> +				      enum mmu_event event);
>  extern void __mmu_notifier_invalidate_page(struct mm_struct *mm,
> -					  unsigned long address);
> +					  unsigned long address,
> +					  enum mmu_event event);
>  extern void __mmu_notifier_invalidate_range_start(struct mm_struct *mm,
> -				  unsigned long start, unsigned long end);
> +						  unsigned long start,
> +						  unsigned long end,
> +						  enum mmu_event event);
>  extern void __mmu_notifier_invalidate_range_end(struct mm_struct *mm,
> -				  unsigned long start, unsigned long end);
> +						unsigned long start,
> +						unsigned long end,
> +						enum mmu_event event);
>  extern void __mmu_notifier_invalidate_range(struct mm_struct *mm,
>  				  unsigned long start, unsigned long end);
>  
> @@ -240,31 +313,38 @@ static inline int mmu_notifier_test_young(struct mm_struct *mm,
>  }
>  
>  static inline void mmu_notifier_change_pte(struct mm_struct *mm,
> -					   unsigned long address, pte_t pte)
> +					   unsigned long address,
> +					   pte_t pte,
> +					   enum mmu_event event)
>  {
>  	if (mm_has_notifiers(mm))
> -		__mmu_notifier_change_pte(mm, address, pte);
> +		__mmu_notifier_change_pte(mm, address, pte, event);
>  }
>  
>  static inline void mmu_notifier_invalidate_page(struct mm_struct *mm,
> -					  unsigned long address)
> +						unsigned long address,
> +						enum mmu_event event)
>  {
>  	if (mm_has_notifiers(mm))
> -		__mmu_notifier_invalidate_page(mm, address);
> +		__mmu_notifier_invalidate_page(mm, address, event);
>  }
>  
>  static inline void mmu_notifier_invalidate_range_start(struct mm_struct *mm,
> -				  unsigned long start, unsigned long end)
> +						       unsigned long start,
> +						       unsigned long end,
> +						       enum mmu_event event)
>  {
>  	if (mm_has_notifiers(mm))
> -		__mmu_notifier_invalidate_range_start(mm, start, end);
> +		__mmu_notifier_invalidate_range_start(mm, start, end, event);
>  }
>  
>  static inline void mmu_notifier_invalidate_range_end(struct mm_struct *mm,
> -				  unsigned long start, unsigned long end)
> +						     unsigned long start,
> +						     unsigned long end,
> +						     enum mmu_event event)
>  {
>  	if (mm_has_notifiers(mm))
> -		__mmu_notifier_invalidate_range_end(mm, start, end);
> +		__mmu_notifier_invalidate_range_end(mm, start, end, event);
>  }
>  
>  static inline void mmu_notifier_invalidate_range(struct mm_struct *mm,
> @@ -359,13 +439,13 @@ static inline void mmu_notifier_mm_destroy(struct mm_struct *mm)
>   * old page would remain mapped readonly in the secondary MMUs after the new
>   * page is already writable by some CPU through the primary MMU.
>   */
> -#define set_pte_at_notify(__mm, __address, __ptep, __pte)		\
> +#define set_pte_at_notify(__mm, __address, __ptep, __pte, __event)	\
>  ({									\
>  	struct mm_struct *___mm = __mm;					\
>  	unsigned long ___address = __address;				\
>  	pte_t ___pte = __pte;						\
>  									\
> -	mmu_notifier_change_pte(___mm, ___address, ___pte);		\
> +	mmu_notifier_change_pte(___mm, ___address, ___pte, __event);	\
>  	set_pte_at(___mm, ___address, __ptep, ___pte);			\
>  })
>  
> @@ -393,22 +473,29 @@ static inline int mmu_notifier_test_young(struct mm_struct *mm,
>  }
>  
>  static inline void mmu_notifier_change_pte(struct mm_struct *mm,
> -					   unsigned long address, pte_t pte)
> +					   unsigned long address,
> +					   pte_t pte,
> +					   enum mmu_event event)
>  {
>  }
>  
>  static inline void mmu_notifier_invalidate_page(struct mm_struct *mm,
> -					  unsigned long address)
> +						unsigned long address,
> +						enum mmu_event event)
>  {
>  }
>  
>  static inline void mmu_notifier_invalidate_range_start(struct mm_struct *mm,
> -				  unsigned long start, unsigned long end)
> +						       unsigned long start,
> +						       unsigned long end,
> +						       enum mmu_event event)
>  {
>  }
>  
>  static inline void mmu_notifier_invalidate_range_end(struct mm_struct *mm,
> -				  unsigned long start, unsigned long end)
> +						     unsigned long start,
> +						     unsigned long end,
> +						     enum mmu_event event)
>  {
>  }
>  
> diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
> index cb346f2..802828a 100644
> --- a/kernel/events/uprobes.c
> +++ b/kernel/events/uprobes.c
> @@ -176,7 +176,8 @@ static int __replace_page(struct vm_area_struct *vma, unsigned long addr,
>  	/* For try_to_free_swap() and munlock_vma_page() below */
>  	lock_page(page);
>  
> -	mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end);
> +	mmu_notifier_invalidate_range_start(mm, mmun_start,
> +					    mmun_end, MMU_MIGRATE);
>  	err = -EAGAIN;
>  	ptep = page_check_address(page, mm, addr, &ptl, 0);
>  	if (!ptep)
> @@ -194,7 +195,9 @@ static int __replace_page(struct vm_area_struct *vma, unsigned long addr,
>  
>  	flush_cache_page(vma, addr, pte_pfn(*ptep));
>  	ptep_clear_flush_notify(vma, addr, ptep);
> -	set_pte_at_notify(mm, addr, ptep, mk_pte(kpage, vma->vm_page_prot));
> +	set_pte_at_notify(mm, addr, ptep,
> +			  mk_pte(kpage, vma->vm_page_prot),
> +			  MMU_MIGRATE);
>  
>  	page_remove_rmap(page);
>  	if (!page_mapped(page))
> @@ -208,7 +211,8 @@ static int __replace_page(struct vm_area_struct *vma, unsigned long addr,
>  	err = 0;
>   unlock:
>  	mem_cgroup_cancel_charge(kpage, memcg);
> -	mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
> +	mmu_notifier_invalidate_range_end(mm, mmun_start,
> +					  mmun_end, MMU_MIGRATE);
>  	unlock_page(page);
>  	return err;
>  }
> diff --git a/mm/filemap_xip.c b/mm/filemap_xip.c
> index 0d105ae..fb97c7c 100644
> --- a/mm/filemap_xip.c
> +++ b/mm/filemap_xip.c
> @@ -193,7 +193,7 @@ retry:
>  			BUG_ON(pte_dirty(pteval));
>  			pte_unmap_unlock(pte, ptl);
>  			/* must invalidate_page _before_ freeing the page */
> -			mmu_notifier_invalidate_page(mm, address);
> +			mmu_notifier_invalidate_page(mm, address, MMU_MIGRATE);
>  			page_cache_release(page);
>  		}
>  	}
> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
> index cf3b67b..75eb651 100644
> --- a/mm/huge_memory.c
> +++ b/mm/huge_memory.c
> @@ -1028,7 +1028,8 @@ static int do_huge_pmd_wp_page_fallback(struct mm_struct *mm,
>  
>  	mmun_start = haddr;
>  	mmun_end   = haddr + HPAGE_PMD_SIZE;
> -	mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end);
> +	mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end,
> +					    MMU_MIGRATE);
>  
>  	ptl = pmd_lock(mm, pmd);
>  	if (unlikely(!pmd_same(*pmd, orig_pmd)))
> @@ -1062,7 +1063,8 @@ static int do_huge_pmd_wp_page_fallback(struct mm_struct *mm,
>  	page_remove_rmap(page);
>  	spin_unlock(ptl);
>  
> -	mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
> +	mmu_notifier_invalidate_range_end(mm, mmun_start,
> +					  mmun_end, MMU_MIGRATE);
>  
>  	ret |= VM_FAULT_WRITE;
>  	put_page(page);
> @@ -1072,7 +1074,8 @@ out:
>  
>  out_free_pages:
>  	spin_unlock(ptl);
> -	mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
> +	mmu_notifier_invalidate_range_end(mm, mmun_start,
> +					  mmun_end, MMU_MIGRATE);
>  	for (i = 0; i < HPAGE_PMD_NR; i++) {
>  		memcg = (void *)page_private(pages[i]);
>  		set_page_private(pages[i], 0);
> @@ -1164,7 +1167,8 @@ alloc:
>  
>  	mmun_start = haddr;
>  	mmun_end   = haddr + HPAGE_PMD_SIZE;
> -	mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end);
> +	mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end,
> +					    MMU_MIGRATE);
>  
>  	spin_lock(ptl);
>  	if (page)
> @@ -1196,7 +1200,8 @@ alloc:
>  	}
>  	spin_unlock(ptl);
>  out_mn:
> -	mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
> +	mmu_notifier_invalidate_range_end(mm, mmun_start,
> +					  mmun_end, MMU_MIGRATE);
>  out:
>  	return ret;
>  out_unlock:
> @@ -1667,7 +1672,8 @@ static int __split_huge_page_splitting(struct page *page,
>  	const unsigned long mmun_start = address;
>  	const unsigned long mmun_end   = address + HPAGE_PMD_SIZE;
>  
> -	mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end);
> +	mmu_notifier_invalidate_range_start(mm, mmun_start,
> +					    mmun_end, MMU_HSPLIT);
>  	pmd = page_check_address_pmd(page, mm, address,
>  			PAGE_CHECK_ADDRESS_PMD_NOTSPLITTING_FLAG, &ptl);
>  	if (pmd) {
> @@ -1683,7 +1689,8 @@ static int __split_huge_page_splitting(struct page *page,
>  		ret = 1;
>  		spin_unlock(ptl);
>  	}
> -	mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
> +	mmu_notifier_invalidate_range_end(mm, mmun_start,
> +					  mmun_end, MMU_HSPLIT);
>  
>  	return ret;
>  }
> @@ -2504,7 +2511,8 @@ static void collapse_huge_page(struct mm_struct *mm,
>  
>  	mmun_start = address;
>  	mmun_end   = address + HPAGE_PMD_SIZE;
> -	mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end);
> +	mmu_notifier_invalidate_range_start(mm, mmun_start,
> +					    mmun_end, MMU_MIGRATE);
>  	pmd_ptl = pmd_lock(mm, pmd); /* probably unnecessary */
>  	/*
>  	 * After this gup_fast can't run anymore. This also removes
> @@ -2514,7 +2522,8 @@ static void collapse_huge_page(struct mm_struct *mm,
>  	 */
>  	_pmd = pmdp_clear_flush(vma, address, pmd);
>  	spin_unlock(pmd_ptl);
> -	mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
> +	mmu_notifier_invalidate_range_end(mm, mmun_start,
> +					  mmun_end, MMU_MIGRATE);
>  
>  	spin_lock(pte_ptl);
>  	isolated = __collapse_huge_page_isolate(vma, address, pte);
> @@ -2905,24 +2914,28 @@ void __split_huge_page_pmd(struct vm_area_struct *vma, unsigned long address,
>  	mmun_start = haddr;
>  	mmun_end   = haddr + HPAGE_PMD_SIZE;
>  again:
> -	mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end);
> +	mmu_notifier_invalidate_range_start(mm, mmun_start,
> +					    mmun_end, MMU_MIGRATE);
>  	ptl = pmd_lock(mm, pmd);
>  	if (unlikely(!pmd_trans_huge(*pmd))) {
>  		spin_unlock(ptl);
> -		mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
> +		mmu_notifier_invalidate_range_end(mm, mmun_start,
> +						  mmun_end, MMU_MIGRATE);
>  		return;
>  	}
>  	if (is_huge_zero_pmd(*pmd)) {
>  		__split_huge_zero_page_pmd(vma, haddr, pmd);
>  		spin_unlock(ptl);
> -		mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
> +		mmu_notifier_invalidate_range_end(mm, mmun_start,
> +						  mmun_end, MMU_MIGRATE);
>  		return;
>  	}
>  	page = pmd_page(*pmd);
>  	VM_BUG_ON_PAGE(!page_count(page), page);
>  	get_page(page);
>  	spin_unlock(ptl);
> -	mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
> +	mmu_notifier_invalidate_range_end(mm, mmun_start,
> +					  mmun_end, MMU_MIGRATE);
>  
>  	split_huge_page(page);
>  
> diff --git a/mm/hugetlb.c b/mm/hugetlb.c
> index 85032de..b4770c4 100644
> --- a/mm/hugetlb.c
> +++ b/mm/hugetlb.c
> @@ -2560,7 +2560,8 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
>  	mmun_start = vma->vm_start;
>  	mmun_end = vma->vm_end;
>  	if (cow)
> -		mmu_notifier_invalidate_range_start(src, mmun_start, mmun_end);
> +		mmu_notifier_invalidate_range_start(src, mmun_start,
> +						    mmun_end, MMU_MIGRATE);
>  
>  	for (addr = vma->vm_start; addr < vma->vm_end; addr += sz) {
>  		spinlock_t *src_ptl, *dst_ptl;
> @@ -2614,7 +2615,8 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
>  	}
>  
>  	if (cow)
> -		mmu_notifier_invalidate_range_end(src, mmun_start, mmun_end);
> +		mmu_notifier_invalidate_range_end(src, mmun_start,
> +						  mmun_end, MMU_MIGRATE);
>  
>  	return ret;
>  }
> @@ -2640,7 +2642,8 @@ void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma,
>  	BUG_ON(end & ~huge_page_mask(h));
>  
>  	tlb_start_vma(tlb, vma);
> -	mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end);
> +	mmu_notifier_invalidate_range_start(mm, mmun_start,
> +					    mmun_end, MMU_MIGRATE);
>  	address = start;
>  again:
>  	for (; address < end; address += sz) {
> @@ -2713,7 +2716,8 @@ unlock:
>  		if (address < end && !ref_page)
>  			goto again;
>  	}
> -	mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
> +	mmu_notifier_invalidate_range_end(mm, mmun_start,
> +					  mmun_end, MMU_MIGRATE);
>  	tlb_end_vma(tlb, vma);
>  }
>  
> @@ -2891,8 +2895,8 @@ retry_avoidcopy:
>  
>  	mmun_start = address & huge_page_mask(h);
>  	mmun_end = mmun_start + huge_page_size(h);
> -	mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end);
> -
> +	mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end,
> +					    MMU_MIGRATE);
>  	/*
>  	 * Retake the page table lock to check for racing updates
>  	 * before the page tables are altered
> @@ -2913,7 +2917,8 @@ retry_avoidcopy:
>  		new_page = old_page;
>  	}
>  	spin_unlock(ptl);
> -	mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
> +	mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end,
> +					  MMU_MIGRATE);
>  out_release_all:
>  	page_cache_release(new_page);
>  out_release_old:
> @@ -3351,7 +3356,7 @@ unsigned long hugetlb_change_protection(struct vm_area_struct *vma,
>  	BUG_ON(address >= end);
>  	flush_cache_range(vma, address, end);
>  
> -	mmu_notifier_invalidate_range_start(mm, start, end);
> +	mmu_notifier_invalidate_range_start(mm, start, end, MMU_MPROT);
>  	i_mmap_lock_write(vma->vm_file->f_mapping);
>  	for (; address < end; address += huge_page_size(h)) {
>  		spinlock_t *ptl;
> @@ -3382,7 +3387,7 @@ unsigned long hugetlb_change_protection(struct vm_area_struct *vma,
>  	flush_tlb_range(vma, start, end);
>  	mmu_notifier_invalidate_range(mm, start, end);
>  	i_mmap_unlock_write(vma->vm_file->f_mapping);
> -	mmu_notifier_invalidate_range_end(mm, start, end);
> +	mmu_notifier_invalidate_range_end(mm, start, end, MMU_MPROT);
>  
>  	return pages << h->order;
>  }
> diff --git a/mm/ksm.c b/mm/ksm.c
> index d247efa..8c3a892 100644
> --- a/mm/ksm.c
> +++ b/mm/ksm.c
> @@ -872,7 +872,8 @@ static int write_protect_page(struct vm_area_struct *vma, struct page *page,
>  
>  	mmun_start = addr;
>  	mmun_end   = addr + PAGE_SIZE;
> -	mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end);
> +	mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end,
> +					    MMU_WRITE_PROTECT);
>  
>  	ptep = page_check_address(page, mm, addr, &ptl, 0);
>  	if (!ptep)
> @@ -904,7 +905,7 @@ static int write_protect_page(struct vm_area_struct *vma, struct page *page,
>  		if (pte_dirty(entry))
>  			set_page_dirty(page);
>  		entry = pte_mkclean(pte_wrprotect(entry));
> -		set_pte_at_notify(mm, addr, ptep, entry);
> +		set_pte_at_notify(mm, addr, ptep, entry, MMU_WRITE_PROTECT);
>  	}
>  	*orig_pte = *ptep;
>  	err = 0;
> @@ -912,7 +913,8 @@ static int write_protect_page(struct vm_area_struct *vma, struct page *page,
>  out_unlock:
>  	pte_unmap_unlock(ptep, ptl);
>  out_mn:
> -	mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
> +	mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end,
> +					  MMU_WRITE_PROTECT);
>  out:
>  	return err;
>  }
> @@ -948,7 +950,8 @@ static int replace_page(struct vm_area_struct *vma, struct page *page,
>  
>  	mmun_start = addr;
>  	mmun_end   = addr + PAGE_SIZE;
> -	mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end);
> +	mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end,
> +					    MMU_MIGRATE);
>  
>  	ptep = pte_offset_map_lock(mm, pmd, addr, &ptl);
>  	if (!pte_same(*ptep, orig_pte)) {
> @@ -961,7 +964,9 @@ static int replace_page(struct vm_area_struct *vma, struct page *page,
>  
>  	flush_cache_page(vma, addr, pte_pfn(*ptep));
>  	ptep_clear_flush_notify(vma, addr, ptep);
> -	set_pte_at_notify(mm, addr, ptep, mk_pte(kpage, vma->vm_page_prot));
> +	set_pte_at_notify(mm, addr, ptep,
> +			  mk_pte(kpage, vma->vm_page_prot),
> +			  MMU_MIGRATE);
>  
>  	page_remove_rmap(page);
>  	if (!page_mapped(page))
> @@ -971,7 +976,8 @@ static int replace_page(struct vm_area_struct *vma, struct page *page,
>  	pte_unmap_unlock(ptep, ptl);
>  	err = 0;
>  out_mn:
> -	mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
> +	mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end,
> +					  MMU_MIGRATE);
>  out:
>  	return err;
>  }
> diff --git a/mm/madvise.c b/mm/madvise.c
> index 6fc9b82..d7ac37a 100644
> --- a/mm/madvise.c
> +++ b/mm/madvise.c
> @@ -376,9 +376,9 @@ static int madvise_free_single_vma(struct vm_area_struct *vma,
>  	tlb_gather_mmu(&tlb, mm, start, end);
>  	update_hiwater_rss(mm);
>  
> -	mmu_notifier_invalidate_range_start(mm, start, end);
> +	mmu_notifier_invalidate_range_start(mm, start, end, MMU_MUNMAP);
>  	madvise_free_page_range(&tlb, vma, start, end);
> -	mmu_notifier_invalidate_range_end(mm, start, end);
> +	mmu_notifier_invalidate_range_end(mm, start, end, MMU_MUNMAP);
>  	tlb_finish_mmu(&tlb, start, end);
>  
>  	return 0;
> diff --git a/mm/memory.c b/mm/memory.c
> index eacfafc..c184ee9 100644
> --- a/mm/memory.c
> +++ b/mm/memory.c
> @@ -1050,7 +1050,7 @@ int copy_page_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
>  	mmun_end   = end;
>  	if (is_cow)
>  		mmu_notifier_invalidate_range_start(src_mm, mmun_start,
> -						    mmun_end);
> +						    mmun_end, MMU_MIGRATE);
>  
>  	ret = 0;
>  	dst_pgd = pgd_offset(dst_mm, addr);
> @@ -1067,7 +1067,8 @@ int copy_page_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
>  	} while (dst_pgd++, src_pgd++, addr = next, addr != end);
>  
>  	if (is_cow)
> -		mmu_notifier_invalidate_range_end(src_mm, mmun_start, mmun_end);
> +		mmu_notifier_invalidate_range_end(src_mm, mmun_start, mmun_end,
> +						  MMU_MIGRATE);
>  	return ret;
>  }
>  
> @@ -1360,10 +1361,12 @@ void unmap_vmas(struct mmu_gather *tlb,
>  {
>  	struct mm_struct *mm = vma->vm_mm;
>  
> -	mmu_notifier_invalidate_range_start(mm, start_addr, end_addr);
> +	mmu_notifier_invalidate_range_start(mm, start_addr,
> +					    end_addr, MMU_MUNMAP);
>  	for ( ; vma && vma->vm_start < end_addr; vma = vma->vm_next)
>  		unmap_single_vma(tlb, vma, start_addr, end_addr, NULL);
> -	mmu_notifier_invalidate_range_end(mm, start_addr, end_addr);
> +	mmu_notifier_invalidate_range_end(mm, start_addr,
> +					  end_addr, MMU_MUNMAP);
>  }
>  
>  /**
> @@ -1385,10 +1388,10 @@ void zap_page_range(struct vm_area_struct *vma, unsigned long start,
>  	lru_add_drain();
>  	tlb_gather_mmu(&tlb, mm, start, end);
>  	update_hiwater_rss(mm);
> -	mmu_notifier_invalidate_range_start(mm, start, end);
> +	mmu_notifier_invalidate_range_start(mm, start, end, MMU_MIGRATE);
>  	for ( ; vma && vma->vm_start < end; vma = vma->vm_next)
>  		unmap_single_vma(&tlb, vma, start, end, details);
> -	mmu_notifier_invalidate_range_end(mm, start, end);
> +	mmu_notifier_invalidate_range_end(mm, start, end, MMU_MIGRATE);
>  	tlb_finish_mmu(&tlb, start, end);
>  }
>  
> @@ -1411,9 +1414,9 @@ static void zap_page_range_single(struct vm_area_struct *vma, unsigned long addr
>  	lru_add_drain();
>  	tlb_gather_mmu(&tlb, mm, address, end);
>  	update_hiwater_rss(mm);
> -	mmu_notifier_invalidate_range_start(mm, address, end);
> +	mmu_notifier_invalidate_range_start(mm, address, end, MMU_MUNMAP);
>  	unmap_single_vma(&tlb, vma, address, end, details);
> -	mmu_notifier_invalidate_range_end(mm, address, end);
> +	mmu_notifier_invalidate_range_end(mm, address, end, MMU_MUNMAP);
>  	tlb_finish_mmu(&tlb, address, end);
>  }
>  
> @@ -2198,7 +2201,8 @@ gotten:
>  
>  	mmun_start  = address & PAGE_MASK;
>  	mmun_end    = mmun_start + PAGE_SIZE;
> -	mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end);
> +	mmu_notifier_invalidate_range_start(mm, mmun_start,
> +					    mmun_end, MMU_MIGRATE);
>  
>  	/*
>  	 * Re-check the pte - we dropped the lock
> @@ -2230,7 +2234,7 @@ gotten:
>  		 * mmu page tables (such as kvm shadow page tables), we want the
>  		 * new page to be mapped directly into the secondary page table.
>  		 */
> -		set_pte_at_notify(mm, address, page_table, entry);
> +		set_pte_at_notify(mm, address, page_table, entry, MMU_MIGRATE);
>  		update_mmu_cache(vma, address, page_table);
>  		if (old_page) {
>  			/*
> @@ -2269,7 +2273,8 @@ gotten:
>  unlock:
>  	pte_unmap_unlock(page_table, ptl);
>  	if (mmun_end > mmun_start)
> -		mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
> +		mmu_notifier_invalidate_range_end(mm, mmun_start,
> +						  mmun_end, MMU_MIGRATE);
>  	if (old_page) {
>  		/*
>  		 * Don't let another task, with possibly unlocked vma,
> diff --git a/mm/migrate.c b/mm/migrate.c
> index 344cdf6..254d5bf 100644
> --- a/mm/migrate.c
> +++ b/mm/migrate.c
> @@ -1801,12 +1801,14 @@ int migrate_misplaced_transhuge_page(struct mm_struct *mm,
>  	WARN_ON(PageLRU(new_page));
>  
>  	/* Recheck the target PMD */
> -	mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end);
> +	mmu_notifier_invalidate_range_start(mm, mmun_start,
> +					    mmun_end, MMU_MIGRATE);
>  	ptl = pmd_lock(mm, pmd);
>  	if (unlikely(!pmd_same(*pmd, entry) || page_count(page) != 2)) {
>  fail_putback:
>  		spin_unlock(ptl);
> -		mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
> +		mmu_notifier_invalidate_range_end(mm, mmun_start,
> +						  mmun_end, MMU_MIGRATE);
>  
>  		/* Reverse changes made by migrate_page_copy() */
>  		if (TestClearPageActive(new_page))
> @@ -1860,7 +1862,8 @@ fail_putback:
>  	page_remove_rmap(page);
>  
>  	spin_unlock(ptl);
> -	mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
> +	mmu_notifier_invalidate_range_end(mm, mmun_start,
> +					  mmun_end, MMU_MIGRATE);
>  
>  	/* Take an "isolate" reference and put new page on the LRU. */
>  	get_page(new_page);
> diff --git a/mm/mmu_notifier.c b/mm/mmu_notifier.c
> index 3b9b3d0..e51ea02 100644
> --- a/mm/mmu_notifier.c
> +++ b/mm/mmu_notifier.c
> @@ -142,8 +142,10 @@ int __mmu_notifier_test_young(struct mm_struct *mm,
>  	return young;
>  }
>  
> -void __mmu_notifier_change_pte(struct mm_struct *mm, unsigned long address,
> -			       pte_t pte)
> +void __mmu_notifier_change_pte(struct mm_struct *mm,
> +			       unsigned long address,
> +			       pte_t pte,
> +			       enum mmu_event event)
>  {
>  	struct mmu_notifier *mn;
>  	int id;
> @@ -151,13 +153,14 @@ void __mmu_notifier_change_pte(struct mm_struct *mm, unsigned long address,
>  	id = srcu_read_lock(&srcu);
>  	hlist_for_each_entry_rcu(mn, &mm->mmu_notifier_mm->list, hlist) {
>  		if (mn->ops->change_pte)
> -			mn->ops->change_pte(mn, mm, address, pte);
> +			mn->ops->change_pte(mn, mm, address, pte, event);
>  	}
>  	srcu_read_unlock(&srcu, id);
>  }
>  
>  void __mmu_notifier_invalidate_page(struct mm_struct *mm,
> -					  unsigned long address)
> +				    unsigned long address,
> +				    enum mmu_event event)
>  {
>  	struct mmu_notifier *mn;
>  	int id;
> @@ -165,13 +168,16 @@ void __mmu_notifier_invalidate_page(struct mm_struct *mm,
>  	id = srcu_read_lock(&srcu);
>  	hlist_for_each_entry_rcu(mn, &mm->mmu_notifier_mm->list, hlist) {
>  		if (mn->ops->invalidate_page)
> -			mn->ops->invalidate_page(mn, mm, address);
> +			mn->ops->invalidate_page(mn, mm, address, event);
>  	}
>  	srcu_read_unlock(&srcu, id);
>  }
>  
>  void __mmu_notifier_invalidate_range_start(struct mm_struct *mm,
> -				  unsigned long start, unsigned long end)
> +					   unsigned long start,
> +					   unsigned long end,
> +					   enum mmu_event event)
> +
>  {
>  	struct mmu_notifier *mn;
>  	int id;
> @@ -179,14 +185,17 @@ void __mmu_notifier_invalidate_range_start(struct mm_struct *mm,
>  	id = srcu_read_lock(&srcu);
>  	hlist_for_each_entry_rcu(mn, &mm->mmu_notifier_mm->list, hlist) {
>  		if (mn->ops->invalidate_range_start)
> -			mn->ops->invalidate_range_start(mn, mm, start, end);
> +			mn->ops->invalidate_range_start(mn, mm, start,
> +							end, event);
>  	}
>  	srcu_read_unlock(&srcu, id);
>  }
>  EXPORT_SYMBOL_GPL(__mmu_notifier_invalidate_range_start);
>  
>  void __mmu_notifier_invalidate_range_end(struct mm_struct *mm,
> -				  unsigned long start, unsigned long end)
> +					 unsigned long start,
> +					 unsigned long end,
> +					 enum mmu_event event)
>  {
>  	struct mmu_notifier *mn;
>  	int id;
> @@ -204,7 +213,8 @@ void __mmu_notifier_invalidate_range_end(struct mm_struct *mm,
>  		if (mn->ops->invalidate_range)
>  			mn->ops->invalidate_range(mn, mm, start, end);
>  		if (mn->ops->invalidate_range_end)
> -			mn->ops->invalidate_range_end(mn, mm, start, end);
> +			mn->ops->invalidate_range_end(mn, mm, start,
> +						      end, event);
>  	}
>  	srcu_read_unlock(&srcu, id);
>  }
> diff --git a/mm/mprotect.c b/mm/mprotect.c
> index ace9345..0f5dbfe 100644
> --- a/mm/mprotect.c
> +++ b/mm/mprotect.c
> @@ -152,7 +152,8 @@ static inline unsigned long change_pmd_range(struct vm_area_struct *vma,
>  		/* invoke the mmu notifier if the pmd is populated */
>  		if (!mni_start) {
>  			mni_start = addr;
> -			mmu_notifier_invalidate_range_start(mm, mni_start, end);
> +			mmu_notifier_invalidate_range_start(mm, mni_start,
> +							    end, MMU_MPROT);
>  		}
>  
>  		if (pmd_trans_huge(*pmd)) {
> @@ -180,7 +181,8 @@ static inline unsigned long change_pmd_range(struct vm_area_struct *vma,
>  	} while (pmd++, addr = next, addr != end);
>  
>  	if (mni_start)
> -		mmu_notifier_invalidate_range_end(mm, mni_start, end);
> +		mmu_notifier_invalidate_range_end(mm, mni_start, end,
> +						  MMU_MPROT);
>  
>  	if (nr_huge_updates)
>  		count_vm_numa_events(NUMA_HUGE_PTE_UPDATES, nr_huge_updates);
> diff --git a/mm/mremap.c b/mm/mremap.c
> index 17fa018..1ede220 100644
> --- a/mm/mremap.c
> +++ b/mm/mremap.c
> @@ -177,7 +177,8 @@ unsigned long move_page_tables(struct vm_area_struct *vma,
>  
>  	mmun_start = old_addr;
>  	mmun_end   = old_end;
> -	mmu_notifier_invalidate_range_start(vma->vm_mm, mmun_start, mmun_end);
> +	mmu_notifier_invalidate_range_start(vma->vm_mm, mmun_start,
> +					    mmun_end, MMU_MIGRATE);
>  
>  	for (; old_addr < old_end; old_addr += extent, new_addr += extent) {
>  		cond_resched();
> @@ -229,7 +230,8 @@ unsigned long move_page_tables(struct vm_area_struct *vma,
>  	if (likely(need_flush))
>  		flush_tlb_range(vma, old_end-len, old_addr);
>  
> -	mmu_notifier_invalidate_range_end(vma->vm_mm, mmun_start, mmun_end);
> +	mmu_notifier_invalidate_range_end(vma->vm_mm, mmun_start,
> +					  mmun_end, MMU_MIGRATE);
>  
>  	return len + old_addr - old_end;	/* how much done */
>  }
> diff --git a/mm/rmap.c b/mm/rmap.c
> index b404783..1d96644 100644
> --- a/mm/rmap.c
> +++ b/mm/rmap.c
> @@ -869,7 +869,7 @@ static int page_mkclean_one(struct page *page, struct vm_area_struct *vma,
>  	pte_unmap_unlock(pte, ptl);
>  
>  	if (ret) {
> -		mmu_notifier_invalidate_page(mm, address);
> +		mmu_notifier_invalidate_page(mm, address, MMU_WRITE_BACK);
>  		(*cleaned)++;
>  	}
>  out:
> @@ -1171,8 +1171,12 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
>  	spinlock_t *ptl;
>  	int ret = SWAP_AGAIN;
>  	enum ttu_flags flags = (enum ttu_flags)arg;
> +	enum mmu_event event = MMU_MIGRATE;
>  	int dirty = 0;
>  
> +	if (flags & TTU_MUNLOCK)
> +		event = MMU_MUNLOCK;
> +
>  	pte = page_check_address(page, mm, address, &ptl, 0);
>  	if (!pte)
>  		goto out;
> @@ -1292,7 +1296,7 @@ discard:
>  out_unmap:
>  	pte_unmap_unlock(pte, ptl);
>  	if (ret != SWAP_FAIL && !(flags & TTU_MUNLOCK))
> -		mmu_notifier_invalidate_page(mm, address);
> +		mmu_notifier_invalidate_page(mm, address, event);
>  out:
>  	return ret;
>  
> @@ -1346,7 +1350,9 @@ out_mlock:
>  #define CLUSTER_MASK	(~(CLUSTER_SIZE - 1))
>  
>  static int try_to_unmap_cluster(unsigned long cursor, unsigned int *mapcount,
> -		struct vm_area_struct *vma, struct page *check_page)
> +				struct vm_area_struct *vma,
> +				struct page *check_page,
> +				enum ttu_flags flags)
>  {
>  	struct mm_struct *mm = vma->vm_mm;
>  	pmd_t *pmd;
> @@ -1360,6 +1366,10 @@ static int try_to_unmap_cluster(unsigned long cursor, unsigned int *mapcount,
>  	unsigned long end;
>  	int ret = SWAP_AGAIN;
>  	int locked_vma = 0;
> +	enum mmu_event event = MMU_MIGRATE;
> +
> +	if (flags & TTU_MUNLOCK)
> +		event = MMU_MUNLOCK;
>  
>  	address = (vma->vm_start + cursor) & CLUSTER_MASK;
>  	end = address + CLUSTER_SIZE;
> @@ -1374,7 +1384,7 @@ static int try_to_unmap_cluster(unsigned long cursor, unsigned int *mapcount,
>  
>  	mmun_start = address;
>  	mmun_end   = end;
> -	mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end);
> +	mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end, event);
>  
>  	/*
>  	 * If we can acquire the mmap_sem for read, and vma is VM_LOCKED,
> @@ -1443,7 +1453,7 @@ static int try_to_unmap_cluster(unsigned long cursor, unsigned int *mapcount,
>  		(*mapcount)--;
>  	}
>  	pte_unmap_unlock(pte - 1, ptl);
> -	mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
> +	mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end, event);
>  	if (locked_vma)
>  		up_read(&vma->vm_mm->mmap_sem);
>  	return ret;
> @@ -1499,7 +1509,9 @@ static int try_to_unmap_nonlinear(struct page *page,
>  			while (cursor < max_nl_cursor &&
>  				cursor < vma->vm_end - vma->vm_start) {
>  				if (try_to_unmap_cluster(cursor, &mapcount,
> -						vma, page) == SWAP_MLOCK)
> +							 vma, page,
> +							 (enum ttu_flags)arg)
> +							 == SWAP_MLOCK)
>  					ret = SWAP_MLOCK;
>  				cursor += CLUSTER_SIZE;
>  				vma->vm_private_data = (void *) cursor;
> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> index 1cc6e2e..bee9357 100644
> --- a/virt/kvm/kvm_main.c
> +++ b/virt/kvm/kvm_main.c
> @@ -254,7 +254,8 @@ static inline struct kvm *mmu_notifier_to_kvm(struct mmu_notifier *mn)
>  
>  static void kvm_mmu_notifier_invalidate_page(struct mmu_notifier *mn,
>  					     struct mm_struct *mm,
> -					     unsigned long address)
> +					     unsigned long address,
> +					     enum mmu_event event)
>  {
>  	struct kvm *kvm = mmu_notifier_to_kvm(mn);
>  	int need_tlb_flush, idx;
> @@ -296,7 +297,8 @@ static void kvm_mmu_notifier_invalidate_page(struct mmu_notifier *mn,
>  static void kvm_mmu_notifier_change_pte(struct mmu_notifier *mn,
>  					struct mm_struct *mm,
>  					unsigned long address,
> -					pte_t pte)
> +					pte_t pte,
> +					enum mmu_event event)
>  {
>  	struct kvm *kvm = mmu_notifier_to_kvm(mn);
>  	int idx;
> @@ -312,7 +314,8 @@ static void kvm_mmu_notifier_change_pte(struct mmu_notifier *mn,
>  static void kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn,
>  						    struct mm_struct *mm,
>  						    unsigned long start,
> -						    unsigned long end)
> +						    unsigned long end,
> +						    enum mmu_event event)
>  {
>  	struct kvm *kvm = mmu_notifier_to_kvm(mn);
>  	int need_tlb_flush = 0, idx;
> @@ -338,7 +341,8 @@ static void kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn,
>  static void kvm_mmu_notifier_invalidate_range_end(struct mmu_notifier *mn,
>  						  struct mm_struct *mm,
>  						  unsigned long start,
> -						  unsigned long end)
> +						  unsigned long end,
> +						  enum mmu_event event)
>  {
>  	struct kvm *kvm = mmu_notifier_to_kvm(mn);
>  
> 

Hi Jerome,

I have a question:
Don't you need to add the "enum mmu_event event" to the new
__mmu_notifier_invalidate_range() and to (*invalidate_range)() as well ?

Those new functions were merged to 3.19.

	Oded

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