virtio-net: Add MTU feature support

This patch allows advising guest with host MTU's by setting
host_mtu parameter.

If VIRTIO_NET_F_MTU has been successfully negotiated, MTU
value is passed to the backend.

Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Aaron Conole <aconole@redhat.com
Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Maxime Coquelin 2016-12-10 16:30:38 +01:00 committed by Michael S. Tsirkin
parent 45a368ad4f
commit a93e599d4a
2 changed files with 20 additions and 0 deletions

View File

@ -55,6 +55,8 @@ static VirtIOFeature feature_sizes[] = {
.end = endof(struct virtio_net_config, status)}, .end = endof(struct virtio_net_config, status)},
{.flags = 1 << VIRTIO_NET_F_MQ, {.flags = 1 << VIRTIO_NET_F_MQ,
.end = endof(struct virtio_net_config, max_virtqueue_pairs)}, .end = endof(struct virtio_net_config, max_virtqueue_pairs)},
{.flags = 1 << VIRTIO_NET_F_MTU,
.end = endof(struct virtio_net_config, mtu)},
{} {}
}; };
@ -81,6 +83,7 @@ static void virtio_net_get_config(VirtIODevice *vdev, uint8_t *config)
virtio_stw_p(vdev, &netcfg.status, n->status); virtio_stw_p(vdev, &netcfg.status, n->status);
virtio_stw_p(vdev, &netcfg.max_virtqueue_pairs, n->max_queues); virtio_stw_p(vdev, &netcfg.max_virtqueue_pairs, n->max_queues);
virtio_stw_p(vdev, &netcfg.mtu, n->net_conf.mtu);
memcpy(netcfg.mac, n->mac, ETH_ALEN); memcpy(netcfg.mac, n->mac, ETH_ALEN);
memcpy(config, &netcfg, n->config_size); memcpy(config, &netcfg, n->config_size);
} }
@ -152,6 +155,16 @@ static void virtio_net_vhost_status(VirtIONet *n, uint8_t status)
qemu_net_queue_purge(qnc->incoming_queue, qnc->peer); qemu_net_queue_purge(qnc->incoming_queue, qnc->peer);
} }
if (virtio_has_feature(vdev->guest_features, VIRTIO_NET_F_MTU)) {
r = vhost_net_set_mtu(get_vhost_net(nc->peer), n->net_conf.mtu);
if (r < 0) {
error_report("%uBytes MTU not supported by the backend",
n->net_conf.mtu);
return;
}
}
n->vhost_started = 1; n->vhost_started = 1;
r = vhost_net_start(vdev, n->nic->ncs, queues); r = vhost_net_start(vdev, n->nic->ncs, queues);
if (r < 0) { if (r < 0) {
@ -1721,6 +1734,7 @@ static void virtio_net_set_config_size(VirtIONet *n, uint64_t host_features)
{ {
int i, config_size = 0; int i, config_size = 0;
virtio_add_feature(&host_features, VIRTIO_NET_F_MAC); virtio_add_feature(&host_features, VIRTIO_NET_F_MAC);
for (i = 0; feature_sizes[i].flags != 0; i++) { for (i = 0; feature_sizes[i].flags != 0; i++) {
if (host_features & feature_sizes[i].flags) { if (host_features & feature_sizes[i].flags) {
config_size = MAX(feature_sizes[i].end, config_size); config_size = MAX(feature_sizes[i].end, config_size);
@ -1750,6 +1764,10 @@ static void virtio_net_device_realize(DeviceState *dev, Error **errp)
NetClientState *nc; NetClientState *nc;
int i; int i;
if (n->net_conf.mtu) {
n->host_features |= (0x1 << VIRTIO_NET_F_MTU);
}
virtio_net_set_config_size(n, n->host_features); virtio_net_set_config_size(n, n->host_features);
virtio_init(vdev, "virtio-net", VIRTIO_ID_NET, n->config_size); virtio_init(vdev, "virtio-net", VIRTIO_ID_NET, n->config_size);
@ -1948,6 +1966,7 @@ static Property virtio_net_properties[] = {
DEFINE_PROP_STRING("tx", VirtIONet, net_conf.tx), DEFINE_PROP_STRING("tx", VirtIONet, net_conf.tx),
DEFINE_PROP_UINT16("rx_queue_size", VirtIONet, net_conf.rx_queue_size, DEFINE_PROP_UINT16("rx_queue_size", VirtIONet, net_conf.rx_queue_size,
VIRTIO_NET_RX_QUEUE_DEFAULT_SIZE), VIRTIO_NET_RX_QUEUE_DEFAULT_SIZE),
DEFINE_PROP_UINT16("host_mtu", VirtIONet, net_conf.mtu, 0),
DEFINE_PROP_END_OF_LIST(), DEFINE_PROP_END_OF_LIST(),
}; };

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@ -36,6 +36,7 @@ typedef struct virtio_net_conf
int32_t txburst; int32_t txburst;
char *tx; char *tx;
uint16_t rx_queue_size; uint16_t rx_queue_size;
uint16_t mtu;
} virtio_net_conf; } virtio_net_conf;
/* Maximum packet size we can receive from tap device: header + 64k */ /* Maximum packet size we can receive from tap device: header + 64k */