vhost: add new ready status flag

This patch adds a new status flag indicating the Virtio device
is ready to operate.

This is required to be able to call rte_vhost_mtu_get() in the
.new_device() callback, as rte_vhost_mtu_get needs that the
negotiation is done, but it is too early to rely on running status
flag, which is set just after .new_device() returns.

Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Acked-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>

diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h
index 02a05f9..daa9328 100644 (file)
--- a/lib/librte_vhost/vhost.h
+++ b/lib/librte_vhost/vhost.h
@@ -46,6 +46,8 @@
 
 /* Used to indicate that the device is running on a data core */
 #define VIRTIO_DEV_RUNNING 1
+/* Used to indicate that the device is ready to operate */
+#define VIRTIO_DEV_READY 2
 
 /* Backend value set by guest. */
 #define VIRTIO_DEV_STOPPED -1

diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
index 640661b..1806c0f 100644 (file)
--- a/lib/librte_vhost/vhost_user.c
+++ b/lib/librte_vhost/vhost_user.c
@@ -678,14 +678,18 @@ vhost_user_set_vring_kick(struct virtio_net *dev, struct VhostUserMsg *pmsg)
                close(vq->kickfd);
        vq->kickfd = file.fd;
 
-       if (virtio_is_ready(dev) && !(dev->flags & VIRTIO_DEV_RUNNING)) {
-               if (dev->dequeue_zero_copy) {
-                       RTE_LOG(INFO, VHOST_CONFIG,
-                               "dequeue zero copy is enabled\n");
-               }
+       if (virtio_is_ready(dev)) {
+               dev->flags |= VIRTIO_DEV_READY;
+
+               if (!(dev->flags & VIRTIO_DEV_RUNNING)) {
+                       if (dev->dequeue_zero_copy) {
+                               RTE_LOG(INFO, VHOST_CONFIG,
+                                               "dequeue zero copy is enabled\n");
+                       }
 
-               if (notify_ops->new_device(dev->vid) == 0)
-                       dev->flags |= VIRTIO_DEV_RUNNING;
+                       if (notify_ops->new_device(dev->vid) == 0)
+                               dev->flags |= VIRTIO_DEV_RUNNING;
+               }
        }
 }
 
@@ -720,6 +724,8 @@ vhost_user_get_vring_base(struct virtio_net *dev,
                notify_ops->destroy_device(dev->vid);
        }
 
+       dev->flags &= ~VIRTIO_DEV_READY;
+
        /* Here we are safe to get the last used index */
        state->num = vq->last_used_idx;