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Diffstat (limited to 'hw/net/virtio-net.c')
-rw-r--r--hw/net/virtio-net.c26
1 files changed, 25 insertions, 1 deletions
diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index 01f1351554..6b8ae2c1fa 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -31,6 +31,11 @@
#define MAC_TABLE_ENTRIES 64
#define MAX_VLAN (1 << 12) /* Per 802.1Q definition */
+/* previously fixed value */
+#define VIRTIO_NET_RX_QUEUE_DEFAULT_SIZE 256
+/* for now, only allow larger queues; with virtio-1, guest can downsize */
+#define VIRTIO_NET_RX_QUEUE_MIN_SIZE VIRTIO_NET_RX_QUEUE_DEFAULT_SIZE
+
/*
* Calculate the number of bytes up to and including the given 'field' of
* 'container'.
@@ -1412,7 +1417,8 @@ static void virtio_net_add_queue(VirtIONet *n, int index)
{
VirtIODevice *vdev = VIRTIO_DEVICE(n);
- n->vqs[index].rx_vq = virtio_add_queue(vdev, 256, virtio_net_handle_rx);
+ n->vqs[index].rx_vq = virtio_add_queue(vdev, n->net_conf.rx_queue_size,
+ virtio_net_handle_rx);
if (n->net_conf.tx && !strcmp(n->net_conf.tx, "timer")) {
n->vqs[index].tx_vq =
virtio_add_queue(vdev, 256, virtio_net_handle_tx_timer);
@@ -1720,6 +1726,22 @@ static void virtio_net_device_realize(DeviceState *dev, Error **errp)
virtio_net_set_config_size(n, n->host_features);
virtio_init(vdev, "virtio-net", VIRTIO_ID_NET, n->config_size);
+ /*
+ * We set a lower limit on RX queue size to what it always was.
+ * Guests that want a smaller ring can always resize it without
+ * help from us (using virtio 1 and up).
+ */
+ if (n->net_conf.rx_queue_size < VIRTIO_NET_RX_QUEUE_MIN_SIZE ||
+ n->net_conf.rx_queue_size > VIRTQUEUE_MAX_SIZE ||
+ (n->net_conf.rx_queue_size & (n->net_conf.rx_queue_size - 1))) {
+ error_setg(errp, "Invalid rx_queue_size (= %" PRIu16 "), "
+ "must be a power of 2 between %d and %d.",
+ n->net_conf.rx_queue_size, VIRTIO_NET_RX_QUEUE_MIN_SIZE,
+ VIRTQUEUE_MAX_SIZE);
+ virtio_cleanup(vdev);
+ return;
+ }
+
n->max_queues = MAX(n->nic_conf.peers.queues, 1);
if (n->max_queues * 2 + 1 > VIRTIO_QUEUE_MAX) {
error_setg(errp, "Invalid number of queues (= %" PRIu32 "), "
@@ -1880,6 +1902,8 @@ static Property virtio_net_properties[] = {
TX_TIMER_INTERVAL),
DEFINE_PROP_INT32("x-txburst", VirtIONet, net_conf.txburst, TX_BURST),
DEFINE_PROP_STRING("tx", VirtIONet, net_conf.tx),
+ DEFINE_PROP_UINT16("rx_queue_size", VirtIONet, net_conf.rx_queue_size,
+ VIRTIO_NET_RX_QUEUE_DEFAULT_SIZE),
DEFINE_PROP_END_OF_LIST(),
};