From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jason Wang Subject: [PATCH 5/6] vhost: mark dirty pages during map uninit Date: Tue, 23 Jul 2019 03:57:17 -0400 Message-ID: <20190723075718.6275-6-jasowang__34760.4799362429$1563868714$gmane$org@redhat.com> References: <20190723075718.6275-1-jasowang@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20190723075718.6275-1-jasowang@redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org To: mst@redhat.com, jasowang@redhat.com Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, virtualization@lists.linux-foundation.org List-Id: virtualization@lists.linuxfoundation.org We don't mark dirty pages if the map was teared down outside MMU notifier. This will lead untracked dirty pages. Fixing by marking dirty pages during map uninit. Reported-by: Michael S. Tsirkin Fixes: 7f466032dc9e ("vhost: access vq metadata through kernel virtual address") Signed-off-by: Jason Wang --- drivers/vhost/vhost.c | 22 ++++++++++++++++------ 1 file changed, 16 insertions(+), 6 deletions(-) diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index 89c9f08b5146..5b8821d00fe4 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -306,6 +306,18 @@ static void vhost_map_unprefetch(struct vhost_map *map) kfree(map); } +static void vhost_set_map_dirty(struct vhost_virtqueue *vq, + struct vhost_map *map, int index) +{ + struct vhost_uaddr *uaddr = &vq->uaddrs[index]; + int i; + + if (uaddr->write) { + for (i = 0; i < map->npages; i++) + set_page_dirty(map->pages[i]); + } +} + static void vhost_uninit_vq_maps(struct vhost_virtqueue *vq) { struct vhost_map *map[VHOST_NUM_ADDRS]; @@ -315,8 +327,10 @@ static void vhost_uninit_vq_maps(struct vhost_virtqueue *vq) for (i = 0; i < VHOST_NUM_ADDRS; i++) { map[i] = rcu_dereference_protected(vq->maps[i], lockdep_is_held(&vq->mmu_lock)); - if (map[i]) + if (map[i]) { + vhost_set_map_dirty(vq, map[i], i); rcu_assign_pointer(vq->maps[i], NULL); + } } spin_unlock(&vq->mmu_lock); @@ -354,7 +368,6 @@ static void vhost_invalidate_vq_start(struct vhost_virtqueue *vq, { struct vhost_uaddr *uaddr = &vq->uaddrs[index]; struct vhost_map *map; - int i; if (!vhost_map_range_overlap(uaddr, start, end)) return; @@ -365,10 +378,7 @@ static void vhost_invalidate_vq_start(struct vhost_virtqueue *vq, map = rcu_dereference_protected(vq->maps[index], lockdep_is_held(&vq->mmu_lock)); if (map) { - if (uaddr->write) { - for (i = 0; i < map->npages; i++) - set_page_dirty(map->pages[i]); - } + vhost_set_map_dirty(vq, map, index); rcu_assign_pointer(vq->maps[index], NULL); } spin_unlock(&vq->mmu_lock); -- 2.18.1