Features could be changed after the feature negotiation. For example,
VHOST_F_LOG_ALL will be set/cleared at the start/end of live migration,
respecitively. Thus, we need a new callback to inform the application
on such change.
Signed-off-by: Yuanhan Liu <yuanhan....@linux.intel.com>
Reviewed-by: Maxime Coquelin <maxime.coque...@redhat.com>
---
doc/guides/prog_guide/vhost_lib.rst | 6 ++++++
lib/librte_vhost/rte_virtio_net.h | 10 +++++++++-
lib/librte_vhost/vhost_user.c | 5 +++++
3 files changed, 20 insertions(+), 1 deletion(-)
diff --git a/doc/guides/prog_guide/vhost_lib.rst
b/doc/guides/prog_guide/vhost_lib.rst
index 88f0591..a4fb1f1 100644
--- a/doc/guides/prog_guide/vhost_lib.rst
+++ b/doc/guides/prog_guide/vhost_lib.rst
@@ -143,6 +143,12 @@ The following is an overview of some key Vhost API
functions:
This callback is invoked when a specific queue's state is changed, for
example to enabled or disabled.
+ * ``features_changed(int vid, uint64_t features)``
+
+ This callback is invoked when the features is changed. For example,
+ ``VHOST_F_LOG_ALL`` will be set/cleared at the start/end of live
+ migration, respectively.
+
* ``rte_vhost_enqueue_burst(vid, queue_id, pkts, count)``
Transmits (enqueues) ``count`` packets from host to guest.
diff --git a/lib/librte_vhost/rte_virtio_net.h
b/lib/librte_vhost/rte_virtio_net.h
index 442f851..ec52a9b 100644
--- a/lib/librte_vhost/rte_virtio_net.h
+++ b/lib/librte_vhost/rte_virtio_net.h
@@ -93,7 +93,15 @@ struct vhost_device_ops {
int (*vring_state_changed)(int vid, uint16_t queue_id, int enable);
/**< triggered when a vring is enabled or disabled */
- void *reserved[5]; /**< Reserved for future extension */
+ /**
+ * Features could be changed after the feature negotiation.
+ * For example, VHOST_F_LOG_ALL will be set/cleared at the
+ * start/end of live migration, respectively. This callback
+ * is used to inform the application on such change.
+ */
+ int (*features_changed)(int vid, uint64_t features);
+
+ void *reserved[4]; /**< Reserved for future extension */
};
/**
diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
index 9140f60..bade6ad 100644
--- a/lib/librte_vhost/vhost_user.c
+++ b/lib/librte_vhost/vhost_user.c
@@ -167,6 +167,11 @@
if (features & ~vhost_features)
return -1;
+ if ((dev->flags & VIRTIO_DEV_RUNNING) && dev->features != features) {
+ if (dev->notify_ops->features_changed)
+ dev->notify_ops->features_changed(dev->vid, features);
+ }
+
dev->features = features;
if (dev->features &
((1 << VIRTIO_NET_F_MRG_RXBUF) | (1ULL << VIRTIO_F_VERSION_1)))
{
--
1.9.0
