diff options
| -rw-r--r-- | arch/x86/include/asm/kvm_host.h | 1 | ||||
| -rw-r--r-- | arch/x86/kvm/mmu.c | 34 | ||||
| -rw-r--r-- | arch/x86/mm/gup.c | 3 | ||||
| -rw-r--r-- | include/linux/mmu_notifier.h | 26 | ||||
| -rw-r--r-- | mm/huge_memory.c | 6 | ||||
| -rw-r--r-- | mm/mmu_notifier.c | 20 | ||||
| -rw-r--r-- | virt/kvm/kvm_main.c | 17 |
7 files changed, 105 insertions, 2 deletions
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index aa75f21a9fb..ffd7f8d2918 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -822,6 +822,7 @@ extern bool kvm_rebooting; #define KVM_ARCH_WANT_MMU_NOTIFIER int kvm_unmap_hva(struct kvm *kvm, unsigned long hva); int kvm_age_hva(struct kvm *kvm, unsigned long hva); +int kvm_test_age_hva(struct kvm *kvm, unsigned long hva); void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte); int cpuid_maxphyaddr(struct kvm_vcpu *vcpu); int kvm_cpu_has_interrupt(struct kvm_vcpu *vcpu); diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 47b2c3288b6..f02b8edc3d4 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -945,6 +945,35 @@ static int kvm_age_rmapp(struct kvm *kvm, unsigned long *rmapp, return young; } +static int kvm_test_age_rmapp(struct kvm *kvm, unsigned long *rmapp, + unsigned long data) +{ + u64 *spte; + int young = 0; + + /* + * If there's no access bit in the secondary pte set by the + * hardware it's up to gup-fast/gup to set the access bit in + * the primary pte or in the page structure. + */ + if (!shadow_accessed_mask) + goto out; + + spte = rmap_next(kvm, rmapp, NULL); + while (spte) { + u64 _spte = *spte; + BUG_ON(!(_spte & PT_PRESENT_MASK)); + young = _spte & PT_ACCESSED_MASK; + if (young) { + young = 1; + break; + } + spte = rmap_next(kvm, rmapp, spte); + } +out: + return young; +} + #define RMAP_RECYCLE_THRESHOLD 1000 static void rmap_recycle(struct kvm_vcpu *vcpu, u64 *spte, gfn_t gfn) @@ -965,6 +994,11 @@ int kvm_age_hva(struct kvm *kvm, unsigned long hva) return kvm_handle_hva(kvm, hva, 0, kvm_age_rmapp); } +int kvm_test_age_hva(struct kvm *kvm, unsigned long hva) +{ + return kvm_handle_hva(kvm, hva, 0, kvm_test_age_rmapp); +} + #ifdef MMU_DEBUG static int is_empty_shadow_page(u64 *spt) { diff --git a/arch/x86/mm/gup.c b/arch/x86/mm/gup.c index 269aa53932e..dbe34b93137 100644 --- a/arch/x86/mm/gup.c +++ b/arch/x86/mm/gup.c @@ -8,6 +8,7 @@ #include <linux/mm.h> #include <linux/vmstat.h> #include <linux/highmem.h> +#include <linux/swap.h> #include <asm/pgtable.h> @@ -89,6 +90,7 @@ static noinline int gup_pte_range(pmd_t pmd, unsigned long addr, VM_BUG_ON(!pfn_valid(pte_pfn(pte))); page = pte_page(pte); get_page(page); + SetPageReferenced(page); pages[*nr] = page; (*nr)++; @@ -103,6 +105,7 @@ static inline void get_head_page_multiple(struct page *page, int nr) VM_BUG_ON(page != compound_head(page)); VM_BUG_ON(page_count(page) == 0); atomic_add(nr, &page->_count); + SetPageReferenced(page); } static inline void get_huge_page_tail(struct page *page) diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h index cbfab1e9957..cc2e7dfea9d 100644 --- a/include/linux/mmu_notifier.h +++ b/include/linux/mmu_notifier.h @@ -62,6 +62,16 @@ struct mmu_notifier_ops { unsigned long address); /* + * test_young is called to check the young/accessed bitflag in + * the secondary pte. This is used to know if the page is + * frequently used without actually clearing the flag or tearing + * down the secondary mapping on the page. + */ + int (*test_young)(struct mmu_notifier *mn, + struct mm_struct *mm, + unsigned long address); + + /* * change_pte is called in cases that pte mapping to page is changed: * for example, when ksm remaps pte to point to a new shared page. */ @@ -163,6 +173,8 @@ extern void __mmu_notifier_mm_destroy(struct mm_struct *mm); extern void __mmu_notifier_release(struct mm_struct *mm); extern int __mmu_notifier_clear_flush_young(struct mm_struct *mm, unsigned long address); +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); extern void __mmu_notifier_invalidate_page(struct mm_struct *mm, @@ -186,6 +198,14 @@ static inline int mmu_notifier_clear_flush_young(struct mm_struct *mm, return 0; } +static inline int mmu_notifier_test_young(struct mm_struct *mm, + unsigned long address) +{ + if (mm_has_notifiers(mm)) + return __mmu_notifier_test_young(mm, address); + return 0; +} + static inline void mmu_notifier_change_pte(struct mm_struct *mm, unsigned long address, pte_t pte) { @@ -313,6 +333,12 @@ static inline int mmu_notifier_clear_flush_young(struct mm_struct *mm, return 0; } +static inline int mmu_notifier_test_young(struct mm_struct *mm, + unsigned long address) +{ + return 0; +} + static inline void mmu_notifier_change_pte(struct mm_struct *mm, unsigned long address, pte_t pte) { diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 915809b16ed..39d7df40c06 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1632,7 +1632,8 @@ static int __collapse_huge_page_isolate(struct vm_area_struct *vma, VM_BUG_ON(PageLRU(page)); /* If there is no mapped pte young don't collapse the page */ - if (pte_young(pteval)) + if (pte_young(pteval) || PageReferenced(page) || + mmu_notifier_test_young(vma->vm_mm, address)) referenced = 1; } if (unlikely(!referenced)) @@ -1892,7 +1893,8 @@ static int khugepaged_scan_pmd(struct mm_struct *mm, /* cannot use mapcount: can't collapse if there's a gup pin */ if (page_count(page) != 1) goto out_unmap; - if (pte_young(pteval)) + if (pte_young(pteval) || PageReferenced(page) || + mmu_notifier_test_young(vma->vm_mm, address)) referenced = 1; } if (referenced) diff --git a/mm/mmu_notifier.c b/mm/mmu_notifier.c index 438951d366f..8d032de4088 100644 --- a/mm/mmu_notifier.c +++ b/mm/mmu_notifier.c @@ -100,6 +100,26 @@ int __mmu_notifier_clear_flush_young(struct mm_struct *mm, return young; } +int __mmu_notifier_test_young(struct mm_struct *mm, + unsigned long address) +{ + struct mmu_notifier *mn; + struct hlist_node *n; + int young = 0; + + rcu_read_lock(); + hlist_for_each_entry_rcu(mn, n, &mm->mmu_notifier_mm->list, hlist) { + if (mn->ops->test_young) { + young = mn->ops->test_young(mn, mm, address); + if (young) + break; + } + } + rcu_read_unlock(); + + return young; +} + void __mmu_notifier_change_pte(struct mm_struct *mm, unsigned long address, pte_t pte) { diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 85ab7db0d36..4286d476651 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -380,6 +380,22 @@ static int kvm_mmu_notifier_clear_flush_young(struct mmu_notifier *mn, return young; } +static int kvm_mmu_notifier_test_young(struct mmu_notifier *mn, + struct mm_struct *mm, + unsigned long address) +{ + struct kvm *kvm = mmu_notifier_to_kvm(mn); + int young, idx; + + idx = srcu_read_lock(&kvm->srcu); + spin_lock(&kvm->mmu_lock); + young = kvm_test_age_hva(kvm, address); + spin_unlock(&kvm->mmu_lock); + srcu_read_unlock(&kvm->srcu, idx); + + return young; +} + static void kvm_mmu_notifier_release(struct mmu_notifier *mn, struct mm_struct *mm) { @@ -396,6 +412,7 @@ static const struct mmu_notifier_ops kvm_mmu_notifier_ops = { .invalidate_range_start = kvm_mmu_notifier_invalidate_range_start, .invalidate_range_end = kvm_mmu_notifier_invalidate_range_end, .clear_flush_young = kvm_mmu_notifier_clear_flush_young, + .test_young = kvm_mmu_notifier_test_young, .change_pte = kvm_mmu_notifier_change_pte, .release = kvm_mmu_notifier_release, }; |