From 997308f9ae72783bf370849ad309c9e42b5d0aa8 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Fri, 5 Apr 2024 07:58:14 -0400 Subject: mmu_notifier: remove the .change_pte() callback The scope of set_pte_at_notify() has reduced more and more through the years. Initially, it was meant for when the change to the PTE was not bracketed by mmu_notifier_invalidate_range_{start,end}(). However, that has not been so for over ten years. During all this period the only implementation of .change_pte() was KVM and it had no actual functionality, because it was called after mmu_notifier_invalidate_range_start() zapped the secondary PTE. Now that this (nonfunctional) user of the .change_pte() callback is gone, the whole callback can be removed. For now, leave in place set_pte_at_notify() even though it is just a synonym for set_pte_at(). Signed-off-by: Paolo Bonzini Reviewed-by: David Hildenbrand Message-ID: <20240405115815.3226315-4-pbonzini@redhat.com> Acked-by: Andrew Morton Signed-off-by: Paolo Bonzini --- mm/mmu_notifier.c | 17 ----------------- 1 file changed, 17 deletions(-) (limited to 'mm') diff --git a/mm/mmu_notifier.c b/mm/mmu_notifier.c index ec3b068cbbe6..8982e6139d07 100644 --- a/mm/mmu_notifier.c +++ b/mm/mmu_notifier.c @@ -424,23 +424,6 @@ 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) -{ - struct mmu_notifier *subscription; - int id; - - id = srcu_read_lock(&srcu); - hlist_for_each_entry_rcu(subscription, - &mm->notifier_subscriptions->list, hlist, - srcu_read_lock_held(&srcu)) { - if (subscription->ops->change_pte) - subscription->ops->change_pte(subscription, mm, address, - pte); - } - srcu_read_unlock(&srcu, id); -} - static int mn_itree_invalidate(struct mmu_notifier_subscriptions *subscriptions, const struct mmu_notifier_range *range) { -- cgit v1.2.3-58-ga151 From f7842747d13d9f4eedba9edec5b834c9d9237717 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Fri, 5 Apr 2024 07:58:15 -0400 Subject: mm: replace set_pte_at_notify() with just set_pte_at() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit With the demise of the .change_pte() MMU notifier callback, there is no notification happening in set_pte_at_notify(). It is a synonym of set_pte_at() and can be replaced with it. Signed-off-by: Paolo Bonzini Reviewed-by: David Hildenbrand Reviewed-by: Philippe Mathieu-Daudé Message-ID: <20240405115815.3226315-5-pbonzini@redhat.com> Acked-by: Andrew Morton Signed-off-by: Paolo Bonzini --- include/linux/mmu_notifier.h | 2 -- kernel/events/uprobes.c | 6 +++--- mm/ksm.c | 4 ++-- mm/memory.c | 7 +------ mm/migrate_device.c | 8 ++------ 5 files changed, 8 insertions(+), 19 deletions(-) (limited to 'mm') diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h index 8c72bf651606..d39ebb10caeb 100644 --- a/include/linux/mmu_notifier.h +++ b/include/linux/mmu_notifier.h @@ -657,6 +657,4 @@ static inline void mmu_notifier_synchronize(void) #endif /* CONFIG_MMU_NOTIFIER */ -#define set_pte_at_notify set_pte_at - #endif /* _LINUX_MMU_NOTIFIER_H */ diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index e4834d23e1d1..1215bc299390 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -18,7 +18,7 @@ #include #include #include /* anon_vma_prepare */ -#include /* set_pte_at_notify */ +#include #include /* folio_free_swap */ #include /* user_enable_single_step */ #include /* notifier mechanism */ @@ -195,8 +195,8 @@ static int __replace_page(struct vm_area_struct *vma, unsigned long addr, flush_cache_page(vma, addr, pte_pfn(ptep_get(pvmw.pte))); ptep_clear_flush(vma, addr, pvmw.pte); if (new_page) - set_pte_at_notify(mm, addr, pvmw.pte, - mk_pte(new_page, vma->vm_page_prot)); + set_pte_at(mm, addr, pvmw.pte, + mk_pte(new_page, vma->vm_page_prot)); folio_remove_rmap_pte(old_folio, old_page, vma); if (!folio_mapped(old_folio)) diff --git a/mm/ksm.c b/mm/ksm.c index 8c001819cf10..108a4d167824 100644 --- a/mm/ksm.c +++ b/mm/ksm.c @@ -1345,7 +1345,7 @@ static int write_protect_page(struct vm_area_struct *vma, struct page *page, if (pte_write(entry)) entry = pte_wrprotect(entry); - set_pte_at_notify(mm, pvmw.address, pvmw.pte, entry); + set_pte_at(mm, pvmw.address, pvmw.pte, entry); } *orig_pte = entry; err = 0; @@ -1447,7 +1447,7 @@ static int replace_page(struct vm_area_struct *vma, struct page *page, * See Documentation/mm/mmu_notifier.rst */ ptep_clear_flush(vma, addr, ptep); - set_pte_at_notify(mm, addr, ptep, newpte); + set_pte_at(mm, addr, ptep, newpte); folio = page_folio(page); folio_remove_rmap_pte(folio, page, vma); diff --git a/mm/memory.c b/mm/memory.c index f2bc6dd15eb8..9a6f4d8aa379 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -3327,13 +3327,8 @@ static vm_fault_t wp_page_copy(struct vm_fault *vmf) ptep_clear_flush(vma, vmf->address, vmf->pte); folio_add_new_anon_rmap(new_folio, vma, vmf->address); folio_add_lru_vma(new_folio, vma); - /* - * We call the notify macro here because, when using secondary - * mmu page tables (such as kvm shadow page tables), we want the - * new page to be mapped directly into the secondary page table. - */ BUG_ON(unshare && pte_write(entry)); - set_pte_at_notify(mm, vmf->address, vmf->pte, entry); + set_pte_at(mm, vmf->address, vmf->pte, entry); update_mmu_cache_range(vmf, vma, vmf->address, vmf->pte, 1); if (old_folio) { /* diff --git a/mm/migrate_device.c b/mm/migrate_device.c index b6c27c76e1a0..66206734b1b9 100644 --- a/mm/migrate_device.c +++ b/mm/migrate_device.c @@ -664,13 +664,9 @@ static void migrate_vma_insert_page(struct migrate_vma *migrate, if (flush) { flush_cache_page(vma, addr, pte_pfn(orig_pte)); ptep_clear_flush(vma, addr, ptep); - set_pte_at_notify(mm, addr, ptep, entry); - update_mmu_cache(vma, addr, ptep); - } else { - /* No need to invalidate - it was non-present before */ - set_pte_at(mm, addr, ptep, entry); - update_mmu_cache(vma, addr, ptep); } + set_pte_at(mm, addr, ptep, entry); + update_mmu_cache(vma, addr, ptep); pte_unmap_unlock(ptep, ptl); *src = MIGRATE_PFN_MIGRATE; -- cgit v1.2.3-58-ga151