diff options
| -rw-r--r-- | drivers/infiniband/hw/hfi1/mmu_rb.c | 1 | ||||
| -rw-r--r-- | drivers/iommu/amd_iommu_v2.c | 1 | ||||
| -rw-r--r-- | drivers/iommu/intel-svm.c | 1 | ||||
| -rw-r--r-- | drivers/misc/sgi-gru/grutlbpurge.c | 1 | ||||
| -rw-r--r-- | include/linux/mmu_notifier.h | 30 | ||||
| -rw-r--r-- | mm/mmu_notifier.c | 31 | ||||
| -rw-r--r-- | virt/kvm/kvm_main.c | 1 |
7 files changed, 63 insertions, 3 deletions
diff --git a/drivers/infiniband/hw/hfi1/mmu_rb.c b/drivers/infiniband/hw/hfi1/mmu_rb.c index e7b3ce123da6..70aceefe14d5 100644 --- a/drivers/infiniband/hw/hfi1/mmu_rb.c +++ b/drivers/infiniband/hw/hfi1/mmu_rb.c @@ -77,6 +77,7 @@ static void do_remove(struct mmu_rb_handler *handler, static void handle_remove(struct work_struct *work); static const struct mmu_notifier_ops mn_opts = { + .flags = MMU_INVALIDATE_DOES_NOT_BLOCK, .invalidate_range_start = mmu_notifier_range_start, }; diff --git a/drivers/iommu/amd_iommu_v2.c b/drivers/iommu/amd_iommu_v2.c index 7d94e1d39e5e..df72493a0f13 100644 --- a/drivers/iommu/amd_iommu_v2.c +++ b/drivers/iommu/amd_iommu_v2.c @@ -427,6 +427,7 @@ static void mn_release(struct mmu_notifier *mn, struct mm_struct *mm) } static const struct mmu_notifier_ops iommu_mn = { + .flags = MMU_INVALIDATE_DOES_NOT_BLOCK, .release = mn_release, .clear_flush_young = mn_clear_flush_young, .invalidate_range = mn_invalidate_range, diff --git a/drivers/iommu/intel-svm.c b/drivers/iommu/intel-svm.c index ed1cf7c5a43b..0a826eb7fe48 100644 --- a/drivers/iommu/intel-svm.c +++ b/drivers/iommu/intel-svm.c @@ -276,6 +276,7 @@ static void intel_mm_release(struct mmu_notifier *mn, struct mm_struct *mm) } static const struct mmu_notifier_ops intel_mmuops = { + .flags = MMU_INVALIDATE_DOES_NOT_BLOCK, .release = intel_mm_release, .change_pte = intel_change_pte, .invalidate_range = intel_invalidate_range, diff --git a/drivers/misc/sgi-gru/grutlbpurge.c b/drivers/misc/sgi-gru/grutlbpurge.c index 9918eda0e05f..a3454eb56fbf 100644 --- a/drivers/misc/sgi-gru/grutlbpurge.c +++ b/drivers/misc/sgi-gru/grutlbpurge.c @@ -258,6 +258,7 @@ static void gru_release(struct mmu_notifier *mn, struct mm_struct *mm) static const struct mmu_notifier_ops gru_mmuops = { + .flags = MMU_INVALIDATE_DOES_NOT_BLOCK, .invalidate_range_start = gru_invalidate_range_start, .invalidate_range_end = gru_invalidate_range_end, .release = gru_release, diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h index b25dc9db19fc..2d07a1ed5a31 100644 --- a/include/linux/mmu_notifier.h +++ b/include/linux/mmu_notifier.h @@ -2,6 +2,7 @@ #ifndef _LINUX_MMU_NOTIFIER_H #define _LINUX_MMU_NOTIFIER_H +#include <linux/types.h> #include <linux/list.h> #include <linux/spinlock.h> #include <linux/mm_types.h> @@ -10,6 +11,9 @@ struct mmu_notifier; struct mmu_notifier_ops; +/* mmu_notifier_ops flags */ +#define MMU_INVALIDATE_DOES_NOT_BLOCK (0x01) + #ifdef CONFIG_MMU_NOTIFIER /* @@ -27,6 +31,15 @@ struct mmu_notifier_mm { struct mmu_notifier_ops { /* + * Flags to specify behavior of callbacks for this MMU notifier. + * Used to determine which context an operation may be called. + * + * MMU_INVALIDATE_DOES_NOT_BLOCK: invalidate_range_* callbacks do not + * block + */ + int flags; + + /* * Called either by mmu_notifier_unregister or when the mm is * being destroyed by exit_mmap, always before all pages are * freed. This can run concurrently with other mmu notifier @@ -137,6 +150,10 @@ struct mmu_notifier_ops { * page. Pages will no longer be referenced by the linux * address space but may still be referenced by sptes until * the last refcount is dropped. + * + * If both of these callbacks cannot block, and invalidate_range + * cannot block, mmu_notifier_ops.flags should have + * MMU_INVALIDATE_DOES_NOT_BLOCK set. */ void (*invalidate_range_start)(struct mmu_notifier *mn, struct mm_struct *mm, @@ -159,12 +176,13 @@ struct mmu_notifier_ops { * external TLB range needs to be flushed. For more in depth * discussion on this see Documentation/vm/mmu_notifier.txt * - * The invalidate_range() function is called under the ptl - * spin-lock and not allowed to sleep. - * * Note that this function might be called with just a sub-range * of what was passed to invalidate_range_start()/end(), if * called between those functions. + * + * If this callback cannot block, and invalidate_range_{start,end} + * cannot block, mmu_notifier_ops.flags should have + * MMU_INVALIDATE_DOES_NOT_BLOCK set. */ void (*invalidate_range)(struct mmu_notifier *mn, struct mm_struct *mm, unsigned long start, unsigned long end); @@ -218,6 +236,7 @@ extern void __mmu_notifier_invalidate_range_end(struct mm_struct *mm, bool only_end); extern void __mmu_notifier_invalidate_range(struct mm_struct *mm, unsigned long start, unsigned long end); +extern bool mm_has_blockable_invalidate_notifiers(struct mm_struct *mm); static inline void mmu_notifier_release(struct mm_struct *mm) { @@ -457,6 +476,11 @@ static inline void mmu_notifier_invalidate_range(struct mm_struct *mm, { } +static inline bool mm_has_blockable_invalidate_notifiers(struct mm_struct *mm) +{ + return false; +} + static inline void mmu_notifier_mm_init(struct mm_struct *mm) { } diff --git a/mm/mmu_notifier.c b/mm/mmu_notifier.c index 96edb33fd09a..eff6b88a993f 100644 --- a/mm/mmu_notifier.c +++ b/mm/mmu_notifier.c @@ -236,6 +236,37 @@ void __mmu_notifier_invalidate_range(struct mm_struct *mm, } EXPORT_SYMBOL_GPL(__mmu_notifier_invalidate_range); +/* + * Must be called while holding mm->mmap_sem for either read or write. + * The result is guaranteed to be valid until mm->mmap_sem is dropped. + */ +bool mm_has_blockable_invalidate_notifiers(struct mm_struct *mm) +{ + struct mmu_notifier *mn; + int id; + bool ret = false; + + WARN_ON_ONCE(!rwsem_is_locked(&mm->mmap_sem)); + + if (!mm_has_notifiers(mm)) + return ret; + + id = srcu_read_lock(&srcu); + hlist_for_each_entry_rcu(mn, &mm->mmu_notifier_mm->list, hlist) { + if (!mn->ops->invalidate_range && + !mn->ops->invalidate_range_start && + !mn->ops->invalidate_range_end) + continue; + + if (!(mn->ops->flags & MMU_INVALIDATE_DOES_NOT_BLOCK)) { + ret = true; + break; + } + } + srcu_read_unlock(&srcu, id); + return ret; +} + static int do_mmu_notifier_register(struct mmu_notifier *mn, struct mm_struct *mm, int take_mmap_sem) diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index d6b9370806f8..35db929f92f0 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -476,6 +476,7 @@ static void kvm_mmu_notifier_release(struct mmu_notifier *mn, } static const struct mmu_notifier_ops kvm_mmu_notifier_ops = { + .flags = MMU_INVALIDATE_DOES_NOT_BLOCK, .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, |