vhost: fix guest notification setting

If rte_vhost_enable_guest_notification is called before
the virtqueue is ready, the configuration is lost.

This patch fixes this by saving the guest notification
enablement value requested by the application, and apply
it before the virtqueue is made ready to the application.

Fixes: 604052ae5395 ("net/vhost: support queue update")

Reported-by: Yinan Wang <yinan.wang@intel.com>
Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Tested-by: Yinan Wang <yinan.wang@intel.com>
Reviewed-by: Chenbo Xia <chenbo.xia@intel.com>

diff --git a/lib/librte_vhost/vhost.c b/lib/librte_vhost/vhost.c
index 14b3e25..8f20a08 100644 (file)
--- a/lib/librte_vhost/vhost.c
+++ b/lib/librte_vhost/vhost.c
@@ -534,6 +534,7 @@ init_vring_queue(struct virtio_net *dev, uint32_t vring_idx)
 
        vq->kickfd = VIRTIO_UNINITIALIZED_EVENTFD;
        vq->callfd = VIRTIO_UNINITIALIZED_EVENTFD;
+       vq->notif_enable = VIRTIO_UNINITIALIZED_NOTIF;
 
        vhost_user_iotlb_init(dev, vring_idx);
        /* Backends are set to -1 indicating an inactive device. */
@@ -1311,6 +1312,23 @@ vhost_enable_notify_packed(struct virtio_net *dev,
        return 0;
 }
 
+int
+vhost_enable_guest_notification(struct virtio_net *dev,
+               struct vhost_virtqueue *vq, int enable)
+{
+       /*
+        * If the virtqueue is not ready yet, it will be applied
+        * when it will become ready.
+        */
+       if (!vq->ready)
+               return 0;
+
+       if (vq_is_packed(dev))
+               return vhost_enable_notify_packed(dev, vq, enable);
+       else
+               return vhost_enable_notify_split(dev, vq, enable);
+}
+
 int
 rte_vhost_enable_guest_notification(int vid, uint16_t queue_id, int enable)
 {
@@ -1325,10 +1343,8 @@ rte_vhost_enable_guest_notification(int vid, uint16_t queue_id, int enable)
 
        rte_spinlock_lock(&vq->access_lock);
 
-       if (vq_is_packed(dev))
-               ret = vhost_enable_notify_packed(dev, vq, enable);
-       else
-               ret = vhost_enable_notify_split(dev, vq, enable);
+       vq->notif_enable = enable;
+       ret = vhost_enable_guest_notification(dev, vq, enable);
 
        rte_spinlock_unlock(&vq->access_lock);
 

diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h
index 0f7212f..a29c663 100644 (file)
--- a/lib/librte_vhost/vhost.h
+++ b/lib/librte_vhost/vhost.h
@@ -164,6 +164,9 @@ struct vhost_virtqueue {
        int                     enabled;
        int                     access_ok;
        int                     ready;
+       int                     notif_enable;
+#define VIRTIO_UNINITIALIZED_NOTIF     (-1)
+
        rte_spinlock_t          access_lock;
 
        /* Used to notify the guest (trigger interrupt) */
@@ -668,6 +671,8 @@ void vhost_enable_dequeue_zero_copy(int vid);
 void vhost_set_builtin_virtio_net(int vid, bool enable);
 void vhost_enable_extbuf(int vid);
 void vhost_enable_linearbuf(int vid);
+int vhost_enable_guest_notification(struct virtio_net *dev,
+               struct vhost_virtqueue *vq, int enable);
 
 struct vhost_device_ops const *vhost_driver_callback_get(const char *path);
 

diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
index 9ddeae3..c3c924f 100644 (file)
--- a/lib/librte_vhost/vhost_user.c
+++ b/lib/librte_vhost/vhost_user.c
@@ -235,6 +235,11 @@ vhost_user_notify_queue_state(struct virtio_net *dev, uint16_t index,
                              int enable)
 {
        struct rte_vdpa_device *vdpa_dev = dev->vdpa_dev;
+       struct vhost_virtqueue *vq = dev->virtqueue[index];
+
+       /* Configure guest notifications on enable */
+       if (enable && vq->notif_enable != VIRTIO_UNINITIALIZED_NOTIF)
+               vhost_enable_guest_notification(dev, vq, vq->notif_enable);
 
        if (vdpa_dev && vdpa_dev->ops->set_vring_state)
                vdpa_dev->ops->set_vring_state(dev->vid, index, enable);
@@ -1640,8 +1645,8 @@ vhost_user_set_vring_call(struct virtio_net **pdev, struct VhostUserMsg *msg,
        vq = dev->virtqueue[file.index];
 
        if (vq->ready) {
-               vhost_user_notify_queue_state(dev, file.index, 0);
                vq->ready = 0;
+               vhost_user_notify_queue_state(dev, file.index, 0);
        }
 
        if (vq->callfd >= 0)
@@ -1903,8 +1908,8 @@ vhost_user_set_vring_kick(struct virtio_net **pdev, struct VhostUserMsg *msg,
        }
 
        if (vq->ready) {
-               vhost_user_notify_queue_state(dev, file.index, 0);
                vq->ready = 0;
+               vhost_user_notify_queue_state(dev, file.index, 0);
        }
 
        if (vq->kickfd >= 0)
@@ -2917,8 +2922,8 @@ skip_to_post_handle:
                bool cur_ready = vq_is_ready(dev, vq);
 
                if (cur_ready != (vq && vq->ready)) {
-                       vhost_user_notify_queue_state(dev, i, cur_ready);
                        vq->ready = cur_ready;
+                       vhost_user_notify_queue_state(dev, i, cur_ready);
                }
        }