From c5f048d8fb69ae9b52a02ff4435b403b2ba19db7 Mon Sep 17 00:00:00 2001 From: Maxime Coquelin Date: Sat, 10 Dec 2016 16:30:36 +0100 Subject: vhost-user: Add MTU protocol feature and op This patch implements VHOST_USER_PROTOCOL_F_NET_MTU protocol feature and VHOST_USER_NET_SET_MTU request so that the backend gets notified of the user defined host MTU. If backend supports VHOST_USER_PROTOCOL_F_REPLY_ACK, QEMU assumes MTU is valid if success is returned. Vhost-net driver sends this request through a new vhost_net_set_mtu vhost_ops entry. Cc: Michael S. Tsirkin Cc: Aaron Conole Signed-off-by: Maxime Coquelin Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- docs/specs/vhost-user.txt | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'docs/specs') diff --git a/docs/specs/vhost-user.txt b/docs/specs/vhost-user.txt index d70bd83b13..036890feb0 100644 --- a/docs/specs/vhost-user.txt +++ b/docs/specs/vhost-user.txt @@ -259,6 +259,7 @@ Protocol features #define VHOST_USER_PROTOCOL_F_LOG_SHMFD 1 #define VHOST_USER_PROTOCOL_F_RARP 2 #define VHOST_USER_PROTOCOL_F_REPLY_ACK 3 +#define VHOST_USER_PROTOCOL_F_MTU 4 Message types ------------- @@ -470,6 +471,21 @@ Message types The first 6 bytes of the payload contain the mac address of the guest to allow the vhost user backend to construct and broadcast the fake RARP. + * VHOST_USER_NET_SET_MTU + + Id: 20 + Equivalent ioctl: N/A + Master payload: u64 + + Set host MTU value exposed to the guest. + This request should be sent only when VIRTIO_NET_F_MTU feature has been + successfully negotiated, VHOST_USER_F_PROTOCOL_FEATURES is present in + VHOST_USER_GET_FEATURES and protocol feature bit + VHOST_USER_PROTOCOL_F_NET_MTU is present in + VHOST_USER_GET_PROTOCOL_FEATURES. + If VHOST_USER_PROTOCOL_F_REPLY_ACK is negotiated, slave must respond + with zero in case the specified MTU is valid, or non-zero otherwise. + VHOST_USER_PROTOCOL_F_REPLY_ACK: ------------------------------- The original vhost-user specification only demands replies for certain -- cgit v1.2.3