Merge branch 'akpm' (patches from Andrew)

Merge third patch-bomb from Andrew Morton:

 - even more of the rest of MM

 - lib/ updates

 - checkpatch updates

 - small changes to a few scruffy filesystems

 - kmod fixes/cleanups

 - kexec updates

 - a dma-mapping cleanup series from hch

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (81 commits)
  dma-mapping: consolidate dma_set_mask
  dma-mapping: consolidate dma_supported
  dma-mapping: cosolidate dma_mapping_error
  dma-mapping: consolidate dma_{alloc,free}_noncoherent
  dma-mapping: consolidate dma_{alloc,free}_{attrs,coherent}
  mm: use vma_is_anonymous() in create_huge_pmd() and wp_huge_pmd()
  mm: make sure all file VMAs have ->vm_ops set
  mm, mpx: add "vm_flags_t vm_flags" arg to do_mmap_pgoff()
  mm: mark most vm_operations_struct const
  namei: fix warning while make xmldocs caused by namei.c
  ipc: convert invalid scenarios to use WARN_ON
  zlib_deflate/deftree: remove bi_reverse()
  lib/decompress_unlzma: Do a NULL check for pointer
  lib/decompressors: use real out buf size for gunzip with kernel
  fs/affs: make root lookup from blkdev logical size
  sysctl: fix int -> unsigned long assignments in INT_MIN case
  kexec: export KERNEL_IMAGE_SIZE to vmcoreinfo
  kexec: align crash_notes allocation to make it be inside one physical page
  kexec: remove unnecessary test in kimage_alloc_crash_control_pages()
  kexec: split kexec_load syscall from kexec core code
  ...

1 files changed, 31 insertions, 0 deletions

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 4662a8877f6c..a25a73147f71 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -397,6 +397,36 @@ static int kvm_mmu_notifier_clear_flush_young(struct mmu_notifier *mn,
         return young;
 }
 
+static int kvm_mmu_notifier_clear_young(struct mmu_notifier *mn,
+                                        struct mm_struct *mm,
+                                        unsigned long start,
+                                        unsigned long end)
+{
+        struct kvm *kvm = mmu_notifier_to_kvm(mn);
+        int young, idx;
+
+        idx = srcu_read_lock(&kvm->srcu);
+        spin_lock(&kvm->mmu_lock);
+        /*
+         * Even though we do not flush TLB, this will still adversely
+         * affect performance on pre-Haswell Intel EPT, where there is
+         * no EPT Access Bit to clear so that we have to tear down EPT
+         * tables instead. If we find this unacceptable, we can always
+         * add a parameter to kvm_age_hva so that it effectively doesn't
+         * do anything on clear_young.
+         *
+         * Also note that currently we never issue secondary TLB flushes
+         * from clear_young, leaving this job up to the regular system
+         * cadence. If we find this inaccurate, we might come up with a
+         * more sophisticated heuristic later.
+         */
+        young = kvm_age_hva(kvm, start, end);
+        spin_unlock(&kvm->mmu_lock);
+        srcu_read_unlock(&kvm->srcu, idx);
+
+        return young;
+}
+
 static int kvm_mmu_notifier_test_young(struct mmu_notifier *mn,
                                        struct mm_struct *mm,
                                        unsigned long address)
@@ -429,6 +459,7 @@ 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,
+        .clear_young            = kvm_mmu_notifier_clear_young,
         .test_young             = kvm_mmu_notifier_test_young,
         .change_pte             = kvm_mmu_notifier_change_pte,
         .release                = kvm_mmu_notifier_release,