path: root/virt
diff options
authorMarcelo Tosatti <>2008-12-10 21:23:26 +0100
committerAvi Kivity <>2009-02-15 02:47:35 +0200
commit85db06e514422ae429b5f85742d8111b70bd56f3 (patch)
tree55acee5d8e3c51f09f44ccfcdd631590819b949d /virt
parent7a0eb1960e8ddcb68ea631caf16815485af0e228 (diff)
KVM: mmu_notifiers release method
The destructor for huge pages uses the backing inode for adjusting hugetlbfs accounting. Hugepage mappings are destroyed by exit_mmap, after mmu_notifier_release, so there are no notifications through unmap_hugepage_range at this point. The hugetlbfs inode can be freed with pages backed by it referenced by the shadow. When the shadow releases its reference, the huge page destructor will access a now freed inode. Implement the release operation for kvm mmu notifiers to release page refs before the hugetlbfs inode is gone. Signed-off-by: Marcelo Tosatti <> Signed-off-by: Avi Kivity <>
Diffstat (limited to 'virt')
1 files changed, 8 insertions, 0 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 3a5a08298aab..0b6f2f71271f 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -789,11 +789,19 @@ static int kvm_mmu_notifier_clear_flush_young(struct mmu_notifier *mn,
return young;
+static void kvm_mmu_notifier_release(struct mmu_notifier *mn,
+ struct mm_struct *mm)
+ struct kvm *kvm = mmu_notifier_to_kvm(mn);
+ kvm_arch_flush_shadow(kvm);
static const struct mmu_notifier_ops kvm_mmu_notifier_ops = {
.invalidate_page = kvm_mmu_notifier_invalidate_page,
.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,
+ .release = kvm_mmu_notifier_release,