This patch implements the function for the application to
get the MTU value.
rte_vhost_get_mtu() fills the mtu parameter with the MTU value
set in QEMU if VIRTIO_NET_F_MTU has been negotiated and returns 0,
-ENOTSUP otherwise.
The function returns -EAGAIN if Virtio feature negotiation
didn't happened yet.
Signed-off-by: Maxime Coquelin <maxime.coque...@redhat.com>
---
lib/librte_vhost/rte_virtio_net.h | 15 +++++++++++++++
lib/librte_vhost/vhost.c | 19 +++++++++++++++++++
2 files changed, 34 insertions(+)
diff --git a/lib/librte_vhost/rte_virtio_net.h
b/lib/librte_vhost/rte_virtio_net.h
index 926039c..56829aa 100644
--- a/lib/librte_vhost/rte_virtio_net.h
+++ b/lib/librte_vhost/rte_virtio_net.h
@@ -100,6 +100,21 @@ int rte_vhost_driver_callback_register(struct
virtio_net_device_ops const * cons
int rte_vhost_driver_session_start(void);
/**
+ * Get the MTU value of the device if set in QEMU.
+ *
+ * @param vid
+ * virtio-net device ID
+ * @param mtu
+ * The variable to store the MTU value
+ *
+ * @return
+ * 0: success
+ * -EAGAIN: device not yet started
+ * -ENOTSUP: device does not support MTU feature
+ */
+int rte_vhost_get_mtu(int vid, uint16_t *mtu);
+
+/**
* Get the numa node from which the virtio net device's memory
* is allocated.
*
diff --git a/lib/librte_vhost/vhost.c b/lib/librte_vhost/vhost.c
index 3974087..80a75e0 100644
--- a/lib/librte_vhost/vhost.c
+++ b/lib/librte_vhost/vhost.c
@@ -313,6 +313,25 @@ vhost_enable_dequeue_zero_copy(int vid)
}
int
+rte_vhost_get_mtu(int vid, uint16_t *mtu)
+{
+ struct virtio_net *dev = get_device(vid);
+
+ if (!dev)
+ return -ENODEV;
+
+ if (!(dev->flags & VIRTIO_DEV_READY))
+ return -EAGAIN;
+
+ if (!(dev->features & VIRTIO_NET_F_MTU))
+ return -ENOTSUP;
+
+ *mtu = dev->mtu;
+
+ return 0;
+}
+
+int
rte_vhost_get_numa_node(int vid)
{
#ifdef RTE_LIBRTE_VHOST_NUMA
--
2.9.3
