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authorMaxime Coquelin <maxime.coquelin@redhat.com>2017-05-23 14:31:19 +0200
committerMichael S. Tsirkin <mst@redhat.com>2017-05-25 21:25:28 +0300
commit75ebec11afe49539f71cc1c494e3010f91c86adb (patch)
tree1965291be3a0308383d201d83de4a3aa1a272ed9 /hw
parentc10595fb348d3fe6991fe9750834bd2ab16d3190 (diff)
virtio_net: Bypass backends for MTU feature negotiation
This patch adds a new internal "x-mtu-bypass-backend" property to bypass backends for MTU feature negotiation. When this property is set, the MTU feature is negotiated as soon as supported by the guest and a MTU value is set via the host_mtu parameter. In case the backend advertises the feature (e.g. DPDK's vhost-user backend), the feature negotiation is propagated down to the backend. When this property is not set, the backend has to support the MTU feature for its negotiation to succeed. For compatibility purpose, this property is disabled for machine types v2.9 and older. Cc: Aaron Conole <aconole@redhat.com> Suggested-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com> Reviewed-by: Vlad Yasevich <vyasevic@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'hw')
-rw-r--r--hw/net/virtio-net.c17
1 files changed, 16 insertions, 1 deletions
diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index 98bd683f31..9a3d769aa2 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -589,7 +589,15 @@ static uint64_t virtio_net_get_features(VirtIODevice *vdev, uint64_t features,
if (!get_vhost_net(nc->peer)) {
return features;
}
- return vhost_net_get_features(get_vhost_net(nc->peer), features);
+ features = vhost_net_get_features(get_vhost_net(nc->peer), features);
+ vdev->backend_features = features;
+
+ if (n->mtu_bypass_backend &&
+ (n->host_features & 1ULL << VIRTIO_NET_F_MTU)) {
+ features |= (1ULL << VIRTIO_NET_F_MTU);
+ }
+
+ return features;
}
static uint64_t virtio_net_bad_features(VirtIODevice *vdev)
@@ -640,6 +648,11 @@ static void virtio_net_set_features(VirtIODevice *vdev, uint64_t features)
VirtIONet *n = VIRTIO_NET(vdev);
int i;
+ if (n->mtu_bypass_backend &&
+ !virtio_has_feature(vdev->backend_features, VIRTIO_NET_F_MTU)) {
+ features &= ~(1ULL << VIRTIO_NET_F_MTU);
+ }
+
virtio_net_set_multiqueue(n,
virtio_has_feature(features, VIRTIO_NET_F_MQ));
@@ -2093,6 +2106,8 @@ static Property virtio_net_properties[] = {
DEFINE_PROP_UINT16("rx_queue_size", VirtIONet, net_conf.rx_queue_size,
VIRTIO_NET_RX_QUEUE_DEFAULT_SIZE),
DEFINE_PROP_UINT16("host_mtu", VirtIONet, net_conf.mtu, 0),
+ DEFINE_PROP_BOOL("x-mtu-bypass-backend", VirtIONet, mtu_bypass_backend,
+ true),
DEFINE_PROP_END_OF_LIST(),
};