diff options
| author | Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> | 2012-02-10 10:28:31 +0400 |
|---|---|---|
| committer | Avi Kivity <avi@redhat.com> | 2012-03-08 16:10:23 +0400 |
| commit | 565f3be2174611f364405bbea2d86e153c2e7e78 (patch) | |
| tree | 6605216c0d4f06043ddf6bbcb9b3d5a82571ccc6 /virt/kvm | |
| parent | db3fe4eb45f3555d91a7124e18cf3a2f2a30eb90 (diff) | |
| download | linux-565f3be2174611f364405bbea2d86e153c2e7e78.tar.xz | |
KVM: mmu_notifier: Flush TLBs before releasing mmu_lock
Other threads may process the same page in that small window and skip
TLB flush and then return before these functions do flush.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Diffstat (limited to 'virt/kvm')
| -rw-r--r-- | virt/kvm/kvm_main.c | 19 |
1 files changed, 10 insertions, 9 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 8340e0e62034..e4431ada5947 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -289,15 +289,15 @@ static void kvm_mmu_notifier_invalidate_page(struct mmu_notifier *mn, */ idx = srcu_read_lock(&kvm->srcu); spin_lock(&kvm->mmu_lock); + kvm->mmu_notifier_seq++; need_tlb_flush = kvm_unmap_hva(kvm, address) | kvm->tlbs_dirty; - spin_unlock(&kvm->mmu_lock); - srcu_read_unlock(&kvm->srcu, idx); - /* we've to flush the tlb before the pages can be freed */ if (need_tlb_flush) kvm_flush_remote_tlbs(kvm); + spin_unlock(&kvm->mmu_lock); + srcu_read_unlock(&kvm->srcu, idx); } static void kvm_mmu_notifier_change_pte(struct mmu_notifier *mn, @@ -335,12 +335,12 @@ static void kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn, for (; start < end; start += PAGE_SIZE) need_tlb_flush |= kvm_unmap_hva(kvm, start); need_tlb_flush |= kvm->tlbs_dirty; - spin_unlock(&kvm->mmu_lock); - srcu_read_unlock(&kvm->srcu, idx); - /* we've to flush the tlb before the pages can be freed */ if (need_tlb_flush) kvm_flush_remote_tlbs(kvm); + + spin_unlock(&kvm->mmu_lock); + srcu_read_unlock(&kvm->srcu, idx); } static void kvm_mmu_notifier_invalidate_range_end(struct mmu_notifier *mn, @@ -378,13 +378,14 @@ static int kvm_mmu_notifier_clear_flush_young(struct mmu_notifier *mn, idx = srcu_read_lock(&kvm->srcu); spin_lock(&kvm->mmu_lock); - young = kvm_age_hva(kvm, address); - spin_unlock(&kvm->mmu_lock); - srcu_read_unlock(&kvm->srcu, idx); + young = kvm_age_hva(kvm, address); if (young) kvm_flush_remote_tlbs(kvm); + spin_unlock(&kvm->mmu_lock); + srcu_read_unlock(&kvm->srcu, idx); + return young; } |