[dpdk-dev] [PATCH v3 1/9] vhost: Enable VIRTIO_NET_F_MTU feature

[Maxime Coquelin <maxime.coquelin@redhat.com>]

This patch enables the new VIRTIO_NET_F_MTU feature,
which makes possible for the host to advise the guest
with its maximum supported MTU.

MTU value is set via QEMU parameters, either via Libvirt XML, or
directly in virtio-net device command line arguments.

Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---
 lib/librte_vhost/vhost.c | 3 ++-
 lib/librte_vhost/vhost.h | 6 +++++-
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/lib/librte_vhost/vhost.c b/lib/librte_vhost/vhost.c
index e415093..3974087 100644
--- a/lib/librte_vhost/vhost.c
+++ b/lib/librte_vhost/vhost.c
@@ -66,7 +66,8 @@
 				(1ULL << VIRTIO_NET_F_GUEST_CSUM) | \
 				(1ULL << VIRTIO_NET_F_GUEST_TSO4) | \
 				(1ULL << VIRTIO_NET_F_GUEST_TSO6) | \
-				(1ULL << VIRTIO_RING_F_INDIRECT_DESC))
+				(1ULL << VIRTIO_RING_F_INDIRECT_DESC) | \
+				(1ULL << VIRTIO_NET_F_MTU))
 
 uint64_t VHOST_FEATURES = VHOST_SUPPORTED_FEATURES;
 
diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h
index 22564f1..6a57bb3 100644
--- a/lib/librte_vhost/vhost.h
+++ b/lib/librte_vhost/vhost.h
@@ -110,11 +110,15 @@ struct vhost_virtqueue {
 	uint16_t                shadow_used_idx;
 } __rte_cache_aligned;
 
-/* Old kernels have no such macro defined */
+/* Old kernels have no such macros defined */
 #ifndef VIRTIO_NET_F_GUEST_ANNOUNCE
  #define VIRTIO_NET_F_GUEST_ANNOUNCE 21
 #endif
 
+#ifndef VIRTIO_NET_F_MTU
+ #define VIRTIO_NET_F_MTU 3
+#endif
+
 
 /*
  * Make an extra wrapper for VIRTIO_NET_F_MQ and
-- 
2.9.3