[PATCH v4 2/2] virtio-net: Clarify the size of the struct virtio_net_hdr for tx

[Parav Pandit <parav@nvidia.com>]

The feature VIRTIO_NET_F_HASH_REPORT only applies to the receive side.
However, when VIRTIO_NET_F_HASH_REPORT feature was introduced, it was
not clarified that the size of the struct virtio_net_hdr on the packet
transmission also uses higher size when VIRTIO_NET_F_HASH_REPORT is
negotiated.

Explicitly clarify this.

Fixes: https://github.com/oasis-tcs/virtio-spec/issues/183
Signed-off-by: Parav Pandit <parav@nvidia.com>

---
changelog:
v2->v3:
- rephrase tx to refer to the rx side virtio_net_hdr consideration
- addressed comments from Xuan
- replaced 'field' with 'structure'
v0->v1:
- addressed comments from Xuan to rewrite tx normative
---
 device-types/net/description.tex | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/device-types/net/description.tex b/device-types/net/description.tex
index 17e33fa..0fd7833 100644
--- a/device-types/net/description.tex
+++ b/device-types/net/description.tex
@@ -528,6 +528,9 @@ \subsubsection{Packet Transmission}\label{sec:Device Types / Network Device / De
 
 \drivernormative{\paragraph}{Packet Transmission}{Device Types / Network Device / Device Operation / Packet Transmission}
 
+For the transmit packet buffer, the driver MUST use the size of the
+structure \field{struct virtio_net_hdr} same as the receive packet buffer.
+
 The driver MUST set \field{num_buffers} to zero.
 
 If VIRTIO_NET_F_CSUM is not negotiated, the driver MUST set
-- 
2.34.1