---

yaml
---
r: 134287
b: refs/heads/master
c: 2a41f71
h: refs/heads/master
i:
  134285: 6f64f9f
  134283: 8e185b4
  134279: 0d86520
  134271: c79aadf
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 073a24364fe6de7eef0a3dec0ec7d48e56624092
+refs/heads/master: 2a41f71d3bd97dde3305b4e1c43ab0eca46e7c71

trunk/drivers/net/virtio_net.c

@@ -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;
@@ -589,6 +591,53 @@ 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);
@@ -752,6 +801,14 @@ 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);
@@ -764,7 +821,7 @@ 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. */
@@ -784,6 +841,9 @@ 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:
@@ -815,6 +875,8 @@ 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)
@@ -834,7 +896,7 @@ 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,
 };
 

trunk/include/linux/virtio_net.h

@@ -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 */