@@ -37,10 +37,12 @@ module_param(gso, bool, 0444);
#define MAX_PACKET_LEN (ETH_HLEN + VLAN_HLEN + ETH_DATA_LEN)
#define GOOD_COPY_LEN 128
+#define VIRTNET_SEND_COMMAND_SG_MAX 0
+
struct virtnet_info
{
struct virtio_device *vdev;
- struct virtqueue *rvq, *svq;
+ struct virtqueue *rvq, *svq, *cvq;
struct net_device *dev;
struct napi_struct napi;
unsigned int status;
@@ -605,6 +607,53 @@ static int virtnet_open(struct net_device *dev)
return 0;
}
+/*
+ * Send command via the control virtqueue and check status. Commands
+ * supported by the hypervisor, as indicated by feature bits, should
+ * never fail unless improperly formated.
+ */
+static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd,
+ struct scatterlist *data, int out, int in)
+{
+ struct scatterlist sg[VIRTNET_SEND_COMMAND_SG_MAX + 2];
+ struct virtio_net_ctrl_hdr ctrl;
+ virtio_net_ctrl_ack status = ~0;
+ unsigned int tmp;
+
+ if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ)) {
+ BUG(); /* Caller should know better */
+ return false;
+ }
+
+ BUG_ON(out + in > VIRTNET_SEND_COMMAND_SG_MAX);
+
+ out++; /* Add header */
+ in++; /* Add return status */
+
+ ctrl.class = class;
+ ctrl.cmd = cmd;
+
+ sg_init_table(sg, out + in);
+
+ sg_set_buf(&sg[0], &ctrl, sizeof(ctrl));
+ memcpy(&sg[1], data, sizeof(struct scatterlist) * (out + in - 2));
+ sg_set_buf(&sg[out + in - 1], &status, sizeof(status));
+
+ if (vi->cvq->vq_ops->add_buf(vi->cvq, sg, out, in, vi) != 0)
+ BUG();
+
+ vi->cvq->vq_ops->kick(vi->cvq);
+
+ /*
+ * Spin for a response, the kick causes an ioport write, trapping
+ * into the hypervisor, so the request should be handled immediately.
+ */
+ while (!vi->cvq->vq_ops->get_buf(vi->cvq, &tmp))
+ cpu_relax();
+
+ return status == VIRTIO_NET_OK;
+}
+
static int virtnet_close(struct net_device *dev)
{
struct virtnet_info *vi = netdev_priv(dev);
@@ -771,6 +820,14 @@ static int virtnet_probe(struct virtio_device *vdev)
goto free_recv;
}
+ if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ)) {
+ vi->cvq = vdev->config->find_vq(vdev, 2, NULL);
+ if (IS_ERR(vi->cvq)) {
+ err = PTR_ERR(vi->svq);
+ goto free_send;
+ }
+ }
+
/* Initialize our empty receive and send queues. */
skb_queue_head_init(&vi->recv);
skb_queue_head_init(&vi->send);
@@ -783,7 +840,7 @@ static int virtnet_probe(struct virtio_device *vdev)
err = register_netdev(dev);
if (err) {
pr_debug("virtio_net: registering device failed\n");
- goto free_send;
+ goto free_ctrl;
}
/* Last of all, set up some receive buffers. */
@@ -803,6 +860,9 @@ static int virtnet_probe(struct virtio_device *vdev)
unregister:
unregister_netdev(dev);
+free_ctrl:
+ if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ))
+ vdev->config->del_vq(vi->cvq);
free_send:
vdev->config->del_vq(vi->svq);
free_recv:
@@ -834,6 +894,8 @@ static void virtnet_remove(struct virtio_device *vdev)
vdev->config->del_vq(vi->svq);
vdev->config->del_vq(vi->rvq);
+ if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ))
+ vdev->config->del_vq(vi->cvq);
unregister_netdev(vi->dev);
while (vi->pages)
@@ -853,7 +915,7 @@ static unsigned int features[] = {
VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6,
VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6,
VIRTIO_NET_F_GUEST_ECN, /* We don't yet handle UFO input. */
- VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS,
+ VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ,
VIRTIO_F_NOTIFY_ON_EMPTY,
};
@@ -23,6 +23,7 @@
#define VIRTIO_NET_F_HOST_UFO 14 /* Host can handle UFO in. */
#define VIRTIO_NET_F_MRG_RXBUF 15 /* Host can merge receive buffers. */
#define VIRTIO_NET_F_STATUS 16 /* virtio_net_config.status available */
+#define VIRTIO_NET_F_CTRL_VQ 17 /* Control channel available */
#define VIRTIO_NET_S_LINK_UP 1 /* Link is up */
@@ -59,4 +60,21 @@ struct virtio_net_hdr_mrg_rxbuf {
__u16 num_buffers; /* Number of merged rx buffers */
};
+/*
+ * Control virtqueue data structures
+ *
+ * The control virtqueue expects a header in the first sg entry
+ * and an ack/status response in the last entry. Data for the
+ * command goes in between.
+ */
+struct virtio_net_ctrl_hdr {
+ __u8 class;
+ __u8 cmd;
+} __attribute__((packed));
+
+typedef __u8 virtio_net_ctrl_ack;
+
+#define VIRTIO_NET_OK 0
+#define VIRTIO_NET_ERR 1
+
#endif /* _LINUX_VIRTIO_NET_H */