@@ -332,6 +332,7 @@ static VirtIOS390DeviceInfo s390_virtio_net = {
net.txtimer, TX_TIMER_INTERVAL),
DEFINE_PROP_INT32("x-txburst", VirtIOS390Device,
net.txburst, TX_BURST),
+ DEFINE_PROP_STRING("tx", VirtIOS390Device, net.tx),
DEFINE_PROP_END_OF_LIST(),
},
};
@@ -300,6 +300,7 @@ static SysBusDeviceInfo syborg_virtio_net_info = {
net.txtimer, TX_TIMER_INTERVAL),
DEFINE_PROP_INT32("x-txburst", SyborgVirtIOProxy,
net.txburst, TX_BURST),
+ DEFINE_PROP_STRING("tx", SyborgVirtIOProxy, net.tx),
DEFINE_PROP_END_OF_LIST(),
}
};
@@ -36,6 +36,7 @@ typedef struct VirtIONet
VirtQueue *ctrl_vq;
NICState *nic;
QEMUTimer *tx_timer;
+ QEMUBH *tx_bh;
uint32_t tx_timeout;
int32_t tx_burst;
int tx_waiting;
@@ -700,7 +701,7 @@ static int32_t virtio_net_flush_tx(VirtIONet *n, VirtQueue *vq)
return num_packets;
}
-static void virtio_net_handle_tx(VirtIODevice *vdev, VirtQueue *vq)
+static void virtio_net_handle_tx_timer(VirtIODevice *vdev, VirtQueue *vq)
{
VirtIONet *n = to_virtio_net(vdev);
@@ -717,6 +718,18 @@ static void virtio_net_handle_tx(VirtIODevice *vdev, VirtQueue *vq)
}
}
+static void virtio_net_handle_tx_bh(VirtIODevice *vdev, VirtQueue *vq)
+{
+ VirtIONet *n = to_virtio_net(vdev);
+
+ if (unlikely(n->tx_waiting)) {
+ return;
+ }
+ virtio_queue_set_notification(vq, 0);
+ qemu_bh_schedule(n->tx_bh);
+ n->tx_waiting = 1;
+}
+
static void virtio_net_tx_timer(void *opaque)
{
VirtIONet *n = opaque;
@@ -731,6 +744,41 @@ static void virtio_net_tx_timer(void *opaque)
virtio_net_flush_tx(n, n->tx_vq);
}
+static void virtio_net_tx_bh(void *opaque)
+{
+ VirtIONet *n = opaque;
+ int32_t ret;
+
+ n->tx_waiting = 0;
+
+ /* Just in case the driver is not ready on more */
+ if (unlikely(!(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK)))
+ return;
+
+ ret = virtio_net_flush_tx(n, n->tx_vq);
+ if (ret == -EBUSY) {
+ return; /* Notification re-enable handled by tx_complete */
+ }
+
+ /* If we flush a full burst of packets, assume there are
+ * more coming and immediately reschedule */
+ if (ret >= n->tx_burst) {
+ qemu_bh_schedule(n->tx_bh);
+ n->tx_waiting = 1;
+ return;
+ }
+
+ /* If less than a full burst, re-enable notification and flush
+ * anything that may have come in while we weren't looking. If
+ * we find something, assume the guest is still active and reschedule */
+ virtio_queue_set_notification(n->tx_vq, 1);
+ if (virtio_net_flush_tx(n, n->tx_vq) > 0) {
+ virtio_queue_set_notification(n->tx_vq, 0);
+ qemu_bh_schedule(n->tx_bh);
+ n->tx_waiting = 1;
+ }
+}
+
static void virtio_net_save(QEMUFile *f, void *opaque)
{
VirtIONet *n = opaque;
@@ -850,8 +898,12 @@ static int virtio_net_load(QEMUFile *f, void *opaque, int version_id)
n->mac_table.first_multi = i;
if (n->tx_waiting) {
- qemu_mod_timer(n->tx_timer,
- qemu_get_clock(vm_clock) + n->tx_timeout);
+ if (n->tx_timer) {
+ qemu_mod_timer(n->tx_timer,
+ qemu_get_clock(vm_clock) + n->tx_timeout);
+ } else {
+ qemu_bh_schedule(n->tx_bh);
+ }
}
return 0;
}
@@ -929,7 +981,22 @@ VirtIODevice *virtio_net_init(DeviceState *dev, NICConf *conf,
n->vdev.reset = virtio_net_reset;
n->vdev.set_status = virtio_net_set_status;
n->rx_vq = virtio_add_queue(&n->vdev, 256, virtio_net_handle_rx);
- n->tx_vq = virtio_add_queue(&n->vdev, 256, virtio_net_handle_tx);
+
+ if (net->tx && strcmp(net->tx, "timer") && strcmp(net->tx, "bh")) {
+ fprintf(stderr, "virtio-net: "
+ "Unknown option tx=%s, valid options: \"timer\" \"bh\"\n",
+ net->tx);
+ fprintf(stderr, "Defaulting to \"bh\"\n");
+ }
+
+ if (net->tx && !strcmp(net->tx, "timer")) {
+ n->tx_vq = virtio_add_queue(&n->vdev, 256, virtio_net_handle_tx_timer);
+ n->tx_timer = qemu_new_timer(vm_clock, virtio_net_tx_timer, n);
+ n->tx_timeout = net->txtimer;
+ } else {
+ n->tx_vq = virtio_add_queue(&n->vdev, 256, virtio_net_handle_tx_bh);
+ n->tx_bh = qemu_bh_new(virtio_net_tx_bh, n);
+ }
n->ctrl_vq = virtio_add_queue(&n->vdev, 64, virtio_net_handle_ctrl);
qemu_macaddr_default_if_unset(&conf->macaddr);
memcpy(&n->mac[0], &conf->macaddr, sizeof(n->mac));
@@ -939,9 +1006,7 @@ VirtIODevice *virtio_net_init(DeviceState *dev, NICConf *conf,
qemu_format_nic_info_str(&n->nic->nc, conf->macaddr.a);
- n->tx_timer = qemu_new_timer(vm_clock, virtio_net_tx_timer, n);
n->tx_waiting = 0;
- n->tx_timeout = net->txtimer;
n->tx_burst = net->txburst;
n->mergeable_rx_bufs = 0;
n->promisc = 1; /* for compatibility */
@@ -974,8 +1039,12 @@ void virtio_net_exit(VirtIODevice *vdev)
qemu_free(n->mac_table.macs);
qemu_free(n->vlans);
- qemu_del_timer(n->tx_timer);
- qemu_free_timer(n->tx_timer);
+ if (n->tx_timer) {
+ qemu_del_timer(n->tx_timer);
+ qemu_free_timer(n->tx_timer);
+ } else {
+ qemu_bh_delete(n->tx_bh);
+ }
virtio_cleanup(&n->vdev);
qemu_del_vlan_client(&n->nic->nc);
@@ -60,6 +60,7 @@ typedef struct virtio_net_conf
{
uint32_t txtimer;
int32_t txburst;
+ char *tx;
} virtio_net_conf;
/* Maximum packet size we can receive from tap device: header + 64k */
@@ -695,6 +695,7 @@ static PCIDeviceInfo virtio_info[] = {
net.txtimer, TX_TIMER_INTERVAL),
DEFINE_PROP_INT32("x-txburst", VirtIOPCIProxy,
net.txburst, TX_BURST),
+ DEFINE_PROP_STRING("tx", VirtIOPCIProxy, net.tx),
DEFINE_PROP_END_OF_LIST(),
},
.qdev.reset = virtio_pci_reset,