vhost: fix leak of fds and mmaps

The common vhost code only supported a single mmap per device. vhost-user
worked around this by saving the address/length/fd of each mmap after the end
of the rte_virtio_memory struct. This only works if the vhost-user code frees
dev->mem, since the common code is unaware of the extra info. The
VHOST_USER_RESET_OWNER message is one situation where the common code frees
dev->mem and leaks the fds and mappings. This happens every time I shut down a
VM.

The new code calls back into the implementation (vhost-user or vhost-cuse) to
clean up these resources.

The vhost-cuse changes are only compile tested.

Signed-off-by: Rich Lane <rich.lane@bigswitch.com>
Acked-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>

diff --git a/lib/librte_vhost/vhost-net.h b/lib/librte_vhost/vhost-net.h
index c69b60b..affbd1a 100644 (file)
--- a/lib/librte_vhost/vhost-net.h
+++ b/lib/librte_vhost/vhost-net.h
@@ -115,4 +115,10 @@ struct vhost_net_device_ops {
 
 
 struct vhost_net_device_ops const *get_virtio_net_callbacks(void);
+
+/*
+ * Backend-specific cleanup. Defined by vhost-cuse and vhost-user.
+ */
+void vhost_backend_cleanup(struct virtio_net *dev);
+
 #endif /* _VHOST_NET_CDEV_H_ */

diff --git a/lib/librte_vhost/vhost_cuse/virtio-net-cdev.c b/lib/librte_vhost/vhost_cuse/virtio-net-cdev.c
index ae2c3fa..374c884 100644 (file)
--- a/lib/librte_vhost/vhost_cuse/virtio-net-cdev.c
+++ b/lib/librte_vhost/vhost_cuse/virtio-net-cdev.c
@@ -421,3 +421,15 @@ int cuse_set_backend(struct vhost_device_ctx ctx, struct vhost_vring_file *file)
 
        return ops->set_backend(ctx, file);
 }
+
+void
+vhost_backend_cleanup(struct virtio_net *dev)
+{
+       /* Unmap QEMU memory file if mapped. */
+       if (dev->mem) {
+               munmap((void *)(uintptr_t)dev->mem->mapped_address,
+                       (size_t)dev->mem->mapped_size);
+               free(dev->mem);
+               dev->mem = NULL;
+       }
+}

diff --git a/lib/librte_vhost/vhost_user/vhost-net-user.c b/lib/librte_vhost/vhost_user/vhost-net-user.c
index cb18396..6ed7669 100644 (file)
--- a/lib/librte_vhost/vhost_user/vhost-net-user.c
+++ b/lib/librte_vhost/vhost_user/vhost-net-user.c
@@ -348,7 +348,6 @@ vserver_message_handler(int connfd, void *dat, int *remove)
                close(connfd);
                *remove = 1;
                free(cfd_ctx);
-               user_destroy_device(ctx);
                ops->destroy_device(ctx);
 
                return;

diff --git a/lib/librte_vhost/vhost_user/virtio-net-user.c b/lib/librte_vhost/vhost_user/virtio-net-user.c
index 4270c98..ffce0d6 100644 (file)
--- a/lib/librte_vhost/vhost_user/virtio-net-user.c
+++ b/lib/librte_vhost/vhost_user/virtio-net-user.c
@@ -94,6 +94,16 @@ free_mem_region(struct virtio_net *dev)
        }
 }
 
+void
+vhost_backend_cleanup(struct virtio_net *dev)
+{
+       if (dev->mem) {
+               free_mem_region(dev);
+               free(dev->mem);
+               dev->mem = NULL;
+       }
+}
+
 int
 user_set_mem_table(struct vhost_device_ctx ctx, struct VhostUserMsg *pmsg)
 {
@@ -344,21 +354,6 @@ user_set_vring_enable(struct vhost_device_ctx ctx,
        return 0;
 }
 
-void
-user_destroy_device(struct vhost_device_ctx ctx)
-{
-       struct virtio_net *dev = get_device(ctx);
-
-       if (dev && (dev->flags & VIRTIO_DEV_RUNNING))
-               notify_ops->destroy_device(dev);
-
-       if (dev && dev->mem) {
-               free_mem_region(dev);
-               free(dev->mem);
-               dev->mem = NULL;
-       }
-}
-
 void
 user_set_protocol_features(struct vhost_device_ctx ctx,
                           uint64_t protocol_features)

diff --git a/lib/librte_vhost/vhost_user/virtio-net-user.h b/lib/librte_vhost/vhost_user/virtio-net-user.h
index 28213f3..559bb46 100644 (file)
--- a/lib/librte_vhost/vhost_user/virtio-net-user.h
+++ b/lib/librte_vhost/vhost_user/virtio-net-user.h
@@ -61,5 +61,4 @@ int user_get_vring_base(struct vhost_device_ctx, struct vhost_vring_state *);
 int user_set_vring_enable(struct vhost_device_ctx ctx,
                          struct vhost_vring_state *state);
 
-void user_destroy_device(struct vhost_device_ctx);
 #endif

diff --git a/lib/librte_vhost/virtio-net.c b/lib/librte_vhost/virtio-net.c
index 9059b11..196e1cf 100644 (file)
--- a/lib/librte_vhost/virtio-net.c
+++ b/lib/librte_vhost/virtio-net.c
@@ -207,13 +207,7 @@ cleanup_device(struct virtio_net *dev, int destroy)
 {
        uint32_t i;
 
-       /* Unmap QEMU memory file if mapped. */
-       if (dev->mem) {
-               munmap((void *)(uintptr_t)dev->mem->mapped_address,
-                       (size_t)dev->mem->mapped_size);
-               free(dev->mem);
-               dev->mem = NULL;
-       }
+       vhost_backend_cleanup(dev);
 
        for (i = 0; i < dev->virt_qp_nb; i++) {
                cleanup_vq(dev->virtqueue[i * VIRTIO_QNUM + VIRTIO_RXQ], destroy);