Merge tag 'virtio-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux

Pull virtio update from Rusty Russell:
 "Some nice cleanups, and even a patch my wife did as a "live" demo for
  Latinoware 2012.

  There's a slightly non-trivial merge in virtio-net, as we cleaned up
  the virtio add_buf interface while DaveM accepted the mq virtio-net
  patches."

* tag 'virtio-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: (27 commits)
  virtio_console: Add support for remoteproc serial
  virtio_console: Merge struct buffer_token into struct port_buffer
  virtio: add drv_to_virtio to make code clearly
  virtio: use dev_to_virtio wrapper in virtio
  virtio-mmio: Fix irq parsing in command line parameter
  virtio_console: Free buffers from out-queue upon close
  virtio: Convert dev_printk(KERN_<LEVEL> to dev_<level>(
  virtio_console: Use kmalloc instead of kzalloc
  virtio_console: Free buffer if splice fails
  virtio: tools: make it clear that virtqueue_add_buf() no longer returns > 0
  virtio: scsi: make it clear that virtqueue_add_buf() no longer returns > 0
  virtio: rpmsg: make it clear that virtqueue_add_buf() no longer returns > 0
  virtio: net: make it clear that virtqueue_add_buf() no longer returns > 0
  virtio: console: make it clear that virtqueue_add_buf() no longer returns > 0
  virtio: make virtqueue_add_buf() returning 0 on success, not capacity.
  virtio: console: don't rely on virtqueue_add_buf() returning capacity.
  virtio_net: don't rely on virtqueue_add_buf() returning capacity.
  virtio-net: remove unused skb_vnet_hdr->num_sg field
  virtio-net: correct capacity math on ring full
  virtio: move queue_index and num_free fields into core struct virtqueue.
  ...

drivers/lguest/core.c

@@ -225,7 +225,7 @@ int run_guest(struct lg_cpu *cpu, unsigned long __user *user)
 			 * eventfd (ie. the appropriate virtqueue thread)?
 			 */
 			if (!send_notify_to_eventfd(cpu)) {
-				/* OK, we tell the main Laucher. */
+				/* OK, we tell the main Launcher. */
 				if (put_user(cpu->pending_notify, user))
 					return -EFAULT;
 				return sizeof(cpu->pending_notify);

drivers/net/virtio_net.c

@@ -130,7 +130,6 @@ struct skb_vnet_hdr {
 		struct virtio_net_hdr hdr;
 		struct virtio_net_hdr_mrg_rxbuf mhdr;
 	};
-	unsigned int num_sg;
 };
 
 struct padded_vnet_hdr {
@@ -530,10 +529,10 @@ static bool try_fill_recv(struct receive_queue *rq, gfp_t gfp)
 			err = add_recvbuf_small(rq, gfp);
 
 		oom = err == -ENOMEM;
-		if (err < 0)
+		if (err)
 			break;
 		++rq->num;
-	} while (err > 0);
+	} while (rq->vq->num_free);
 	if (unlikely(rq->num > rq->max))
 		rq->max = rq->num;
 	virtqueue_kick(rq->vq);
@@ -640,10 +639,10 @@ static int virtnet_open(struct net_device *dev)
 	return 0;
 }
 
-static unsigned int free_old_xmit_skbs(struct send_queue *sq)
+static void free_old_xmit_skbs(struct send_queue *sq)
 {
 	struct sk_buff *skb;
-	unsigned int len, tot_sgs = 0;
+	unsigned int len;
 	struct virtnet_info *vi = sq->vq->vdev->priv;
 	struct virtnet_stats *stats = this_cpu_ptr(vi->stats);
 
@@ -655,10 +654,8 @@ static unsigned int free_old_xmit_skbs(struct send_queue *sq)
 		stats->tx_packets++;
 		u64_stats_update_end(&stats->tx_syncp);
 
-		tot_sgs += skb_vnet_hdr(skb)->num_sg;
 		dev_kfree_skb_any(skb);
 	}
-	return tot_sgs;
 }
 
 static int xmit_skb(struct send_queue *sq, struct sk_buff *skb)
@@ -666,6 +663,7 @@ static int xmit_skb(struct send_queue *sq, struct sk_buff *skb)
 	struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb);
 	const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
 	struct virtnet_info *vi = sq->vq->vdev->priv;
+	unsigned num_sg;
 
 	pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest);
 
@@ -704,8 +702,8 @@ static int xmit_skb(struct send_queue *sq, struct sk_buff *skb)
 	else
 		sg_set_buf(sq->sg, &hdr->hdr, sizeof hdr->hdr);
 
-	hdr->num_sg = skb_to_sgvec(skb, sq->sg + 1, 0, skb->len) + 1;
-	return virtqueue_add_buf(sq->vq, sq->sg, hdr->num_sg,
+	num_sg = skb_to_sgvec(skb, sq->sg + 1, 0, skb->len) + 1;
+	return virtqueue_add_buf(sq->vq, sq->sg, num_sg,
 				 0, skb, GFP_ATOMIC);
 }
 
@@ -714,28 +712,20 @@ static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
 	struct virtnet_info *vi = netdev_priv(dev);
 	int qnum = skb_get_queue_mapping(skb);
 	struct send_queue *sq = &vi->sq[qnum];
-	int capacity;
+	int err;
 
 	/* Free up any pending old buffers before queueing new ones. */
 	free_old_xmit_skbs(sq);
 
 	/* Try to transmit */
-	capacity = xmit_skb(sq, skb);
+	err = xmit_skb(sq, skb);
 
-	/* This can happen with OOM and indirect buffers. */
-	if (unlikely(capacity < 0)) {
-		if (likely(capacity == -ENOMEM)) {
-			if (net_ratelimit())
-				dev_warn(&dev->dev,
-					 "TXQ (%d) failure: out of memory\n",
-					 qnum);
-		} else {
+	/* This should not happen! */
+	if (unlikely(err)) {
 		dev->stats.tx_fifo_errors++;
 		if (net_ratelimit())
 			dev_warn(&dev->dev,
-					 "Unexpected TXQ (%d) failure: %d\n",
-					 qnum, capacity);
-		}
+				 "Unexpected TXQ (%d) queue failure: %d\n", qnum, err);
 		dev->stats.tx_dropped++;
 		kfree_skb(skb);
 		return NETDEV_TX_OK;
@@ -748,12 +738,12 @@ static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
 
 	/* Apparently nice girls don't return TX_BUSY; stop the queue
 	 * before it gets out of hand.  Naturally, this wastes entries. */
-	if (capacity < 2+MAX_SKB_FRAGS) {
+	if (sq->vq->num_free < 2+MAX_SKB_FRAGS) {
 		netif_stop_subqueue(dev, qnum);
 		if (unlikely(!virtqueue_enable_cb_delayed(sq->vq))) {
 			/* More just got used, free them then recheck. */
-			capacity += free_old_xmit_skbs(sq);
-			if (capacity >= 2+MAX_SKB_FRAGS) {
+			free_old_xmit_skbs(sq);
+			if (sq->vq->num_free >= 2+MAX_SKB_FRAGS) {
 				netif_start_subqueue(dev, qnum);
 				virtqueue_disable_cb(sq->vq);
 			}

drivers/rpmsg/virtio_rpmsg_bus.c

@@ -764,7 +764,7 @@ int rpmsg_send_offchannel_raw(struct rpmsg_channel *rpdev, u32 src, u32 dst,
 
 	/* add message to the remote processor's virtqueue */
 	err = virtqueue_add_buf(vrp->svq, &sg, 1, 0, msg, GFP_KERNEL);
-	if (err < 0) {
+	if (err) {
 		/*
 		 * need to reclaim the buffer here, otherwise it's lost
 		 * (memory won't leak, but rpmsg won't use it again for TX).
@@ -776,8 +776,6 @@ int rpmsg_send_offchannel_raw(struct rpmsg_channel *rpdev, u32 src, u32 dst,
 
 	/* tell the remote processor it has a pending message to read */
 	virtqueue_kick(vrp->svq);
-
-	err = 0;
 out:
 	mutex_unlock(&vrp->tx_lock);
 	return err;
@@ -980,7 +978,7 @@ static int rpmsg_probe(struct virtio_device *vdev)
 
 		err = virtqueue_add_buf(vrp->rvq, &sg, 0, 1, cpu_addr,
 								GFP_KERNEL);
-		WARN_ON(err < 0); /* sanity check; this can't really happen */
+		WARN_ON(err); /* sanity check; this can't really happen */
 	}
 
 	/* suppress "tx-complete" interrupts */

drivers/scsi/virtio_scsi.c

@@ -215,7 +215,7 @@ static void virtscsi_ctrl_done(struct virtqueue *vq)
 static int virtscsi_kick_event(struct virtio_scsi *vscsi,
 			       struct virtio_scsi_event_node *event_node)
 {
-	int ret;
+	int err;
 	struct scatterlist sg;
 	unsigned long flags;
 
@@ -223,13 +223,14 @@ static int virtscsi_kick_event(struct virtio_scsi *vscsi,
 
 	spin_lock_irqsave(&vscsi->event_vq.vq_lock, flags);
 
-	ret = virtqueue_add_buf(vscsi->event_vq.vq, &sg, 0, 1, event_node, GFP_ATOMIC);
-	if (ret >= 0)
+	err = virtqueue_add_buf(vscsi->event_vq.vq, &sg, 0, 1, event_node,
+				GFP_ATOMIC);
+	if (!err)
 		virtqueue_kick(vscsi->event_vq.vq);
 
 	spin_unlock_irqrestore(&vscsi->event_vq.vq_lock, flags);
 
-	return ret;
+	return err;
 }
 
 static int virtscsi_kick_event_all(struct virtio_scsi *vscsi)
@@ -410,22 +411,23 @@ static int virtscsi_kick_cmd(struct virtio_scsi_target_state *tgt,
 {
 	unsigned int out_num, in_num;
 	unsigned long flags;
-	int ret;
+	int err;
+	bool needs_kick = false;
 
 	spin_lock_irqsave(&tgt->tgt_lock, flags);
 	virtscsi_map_cmd(tgt, cmd, &out_num, &in_num, req_size, resp_size);
 
 	spin_lock(&vq->vq_lock);
-	ret = virtqueue_add_buf(vq->vq, tgt->sg, out_num, in_num, cmd, gfp);
+	err = virtqueue_add_buf(vq->vq, tgt->sg, out_num, in_num, cmd, gfp);
 	spin_unlock(&tgt->tgt_lock);
-	if (ret >= 0)
-		ret = virtqueue_kick_prepare(vq->vq);
+	if (!err)
+		needs_kick = virtqueue_kick_prepare(vq->vq);
 
 	spin_unlock_irqrestore(&vq->vq_lock, flags);
 
-	if (ret > 0)
+	if (needs_kick)
 		virtqueue_notify(vq->vq);
-	return ret;
+	return err;
 }
 
 static int virtscsi_queuecommand(struct Scsi_Host *sh, struct scsi_cmnd *sc)
@@ -467,7 +469,7 @@ static int virtscsi_queuecommand(struct Scsi_Host *sh, struct scsi_cmnd *sc)
 
 	if (virtscsi_kick_cmd(tgt, &vscsi->req_vq, cmd,
 			      sizeof cmd->req.cmd, sizeof cmd->resp.cmd,
-			      GFP_ATOMIC) >= 0)
+			      GFP_ATOMIC) == 0)
 		ret = 0;
 	else
 		mempool_free(cmd, virtscsi_cmd_pool);

drivers/virtio/virtio.c

@@ -10,33 +10,32 @@ static DEFINE_IDA(virtio_index_ida);
 static ssize_t device_show(struct device *_d,
 			   struct device_attribute *attr, char *buf)
 {
-	struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
+	struct virtio_device *dev = dev_to_virtio(_d);
 	return sprintf(buf, "0x%04x\n", dev->id.device);
 }
 static ssize_t vendor_show(struct device *_d,
 			   struct device_attribute *attr, char *buf)
 {
-	struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
+	struct virtio_device *dev = dev_to_virtio(_d);
 	return sprintf(buf, "0x%04x\n", dev->id.vendor);
 }
 static ssize_t status_show(struct device *_d,
 			   struct device_attribute *attr, char *buf)
 {
-	struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
+	struct virtio_device *dev = dev_to_virtio(_d);
 	return sprintf(buf, "0x%08x\n", dev->config->get_status(dev));
 }
 static ssize_t modalias_show(struct device *_d,
 			     struct device_attribute *attr, char *buf)
 {
-	struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
-
+	struct virtio_device *dev = dev_to_virtio(_d);
 	return sprintf(buf, "virtio:d%08Xv%08X\n",
 		       dev->id.device, dev->id.vendor);
 }
 static ssize_t features_show(struct device *_d,
 			     struct device_attribute *attr, char *buf)
 {
-	struct virtio_device *dev = container_of(_d, struct virtio_device, dev);
+	struct virtio_device *dev = dev_to_virtio(_d);
 	unsigned int i;
 	ssize_t len = 0;
 
@@ -71,10 +70,10 @@ static inline int virtio_id_match(const struct virtio_device *dev,
 static int virtio_dev_match(struct device *_dv, struct device_driver *_dr)
 {
 	unsigned int i;
-	struct virtio_device *dev = container_of(_dv,struct virtio_device,dev);
+	struct virtio_device *dev = dev_to_virtio(_dv);
 	const struct virtio_device_id *ids;
 
-	ids = container_of(_dr, struct virtio_driver, driver)->id_table;
+	ids = drv_to_virtio(_dr)->id_table;
 	for (i = 0; ids[i].device; i++)
 		if (virtio_id_match(dev, &ids[i]))
 			return 1;
@@ -83,7 +82,7 @@ static int virtio_dev_match(struct device *_dv, struct device_driver *_dr)
 
 static int virtio_uevent(struct device *_dv, struct kobj_uevent_env *env)
 {
-	struct virtio_device *dev = container_of(_dv,struct virtio_device,dev);
+	struct virtio_device *dev = dev_to_virtio(_dv);
 
 	return add_uevent_var(env, "MODALIAS=virtio:d%08Xv%08X",
 			      dev->id.device, dev->id.vendor);
@@ -98,8 +97,7 @@ void virtio_check_driver_offered_feature(const struct virtio_device *vdev,
 					 unsigned int fbit)
 {
 	unsigned int i;
-	struct virtio_driver *drv = container_of(vdev->dev.driver,
-						 struct virtio_driver, driver);
+	struct virtio_driver *drv = drv_to_virtio(vdev->dev.driver);
 
 	for (i = 0; i < drv->feature_table_size; i++)
 		if (drv->feature_table[i] == fbit)
@@ -111,9 +109,8 @@ EXPORT_SYMBOL_GPL(virtio_check_driver_offered_feature);
 static int virtio_dev_probe(struct device *_d)
 {
 	int err, i;
-	struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
-	struct virtio_driver *drv = container_of(dev->dev.driver,
-						 struct virtio_driver, driver);
+	struct virtio_device *dev = dev_to_virtio(_d);
+	struct virtio_driver *drv = drv_to_virtio(dev->dev.driver);
 	u32 device_features;
 
 	/* We have a driver! */
@@ -152,9 +149,8 @@ static int virtio_dev_probe(struct device *_d)
 
 static int virtio_dev_remove(struct device *_d)
 {
-	struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
-	struct virtio_driver *drv = container_of(dev->dev.driver,
-						 struct virtio_driver, driver);
+	struct virtio_device *dev = dev_to_virtio(_d);
+	struct virtio_driver *drv = drv_to_virtio(dev->dev.driver);
 
 	drv->remove(dev);
 

drivers/virtio/virtio_balloon.c

@@ -139,8 +139,7 @@ static void fill_balloon(struct virtio_balloon *vb, size_t num)
 		struct page *page = balloon_page_enqueue(vb_dev_info);
 
 		if (!page) {
-			if (printk_ratelimit())
-				dev_printk(KERN_INFO, &vb->vdev->dev,
+			dev_info_ratelimited(&vb->vdev->dev,
 					     "Out of puff! Can't get %u pages\n",
 					     VIRTIO_BALLOON_PAGES_PER_PAGE);
 			/* Sleep for at least 1/5 of a second before retry. */

drivers/virtio/virtio_mmio.c

@@ -225,7 +225,7 @@ static void vm_notify(struct virtqueue *vq)
 
 	/* We write the queue's selector into the notification register to
 	 * signal the other end */
-	writel(virtqueue_get_queue_index(vq), vm_dev->base + VIRTIO_MMIO_QUEUE_NOTIFY);
+	writel(vq->index, vm_dev->base + VIRTIO_MMIO_QUEUE_NOTIFY);
 }
 
 /* Notify all virtqueues on an interrupt. */
@@ -266,7 +266,7 @@ static void vm_del_vq(struct virtqueue *vq)
 	struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vq->vdev);
 	struct virtio_mmio_vq_info *info = vq->priv;
 	unsigned long flags, size;
-	unsigned int index = virtqueue_get_queue_index(vq);
+	unsigned int index = vq->index;
 
 	spin_lock_irqsave(&vm_dev->lock, flags);
 	list_del(&info->node);
@@ -521,25 +521,33 @@ static int vm_cmdline_set(const char *device,
 	int err;
 	struct resource resources[2] = {};
 	char *str;
-	long long int base;
+	long long int base, size;
+	unsigned int irq;
 	int processed, consumed = 0;
 	struct platform_device *pdev;
 
-	resources[0].flags = IORESOURCE_MEM;
-	resources[1].flags = IORESOURCE_IRQ;
-
-	resources[0].end = memparse(device, &str) - 1;
+	/* Consume "size" part of the command line parameter */
+	size = memparse(device, &str);
 
+	/* Get "@<base>:<irq>[:<id>]" chunks */
 	processed = sscanf(str, "@%lli:%u%n:%d%n",
-			&base, &resources[1].start, &consumed,
+			&base, &irq, &consumed,
 			&vm_cmdline_id, &consumed);
 
-	if (processed < 2 || processed > 3 || str[consumed])
+	/*
+	 * sscanf() must processes at least 2 chunks; also there
+	 * must be no extra characters after the last chunk, so
+	 * str[consumed] must be '\0'
+	 */
+	if (processed < 2 || str[consumed])
 		return -EINVAL;
 
+	resources[0].flags = IORESOURCE_MEM;
 	resources[0].start = base;
-	resources[0].end += base;
-	resources[1].end = resources[1].start;
+	resources[0].end = base + size - 1;
+
+	resources[1].flags = IORESOURCE_IRQ;
+	resources[1].start = resources[1].end = irq;
 
 	if (!vm_cmdline_parent_registered) {
 		err = device_register(&vm_cmdline_parent);

drivers/virtio/virtio_pci.c

@@ -203,8 +203,7 @@ static void vp_notify(struct virtqueue *vq)
 
 	/* we write the queue's selector into the notification register to
 	 * signal the other end */
-	iowrite16(virtqueue_get_queue_index(vq),
-		  vp_dev->ioaddr + VIRTIO_PCI_QUEUE_NOTIFY);
+	iowrite16(vq->index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_NOTIFY);
 }
 
 /* Handle a configuration change: Tell driver if it wants to know. */
@@ -479,8 +478,7 @@ static void vp_del_vq(struct virtqueue *vq)
 	list_del(&info->node);
 	spin_unlock_irqrestore(&vp_dev->lock, flags);
 
-	iowrite16(virtqueue_get_queue_index(vq),
-		vp_dev->ioaddr + VIRTIO_PCI_QUEUE_SEL);
+	iowrite16(vq->index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_SEL);
 
 	if (vp_dev->msix_enabled) {
 		iowrite16(VIRTIO_MSI_NO_VECTOR,
@@ -830,16 +828,4 @@ static struct pci_driver virtio_pci_driver = {
 #endif
 };
 
-static int __init virtio_pci_init(void)
-{
-	return pci_register_driver(&virtio_pci_driver);
-}
-
-module_init(virtio_pci_init);
-
-static void __exit virtio_pci_exit(void)
-{
-	pci_unregister_driver(&virtio_pci_driver);
-}
-
-module_exit(virtio_pci_exit);
+module_pci_driver(virtio_pci_driver);

drivers/virtio/virtio_ring.c

@@ -93,8 +93,6 @@ struct vring_virtqueue
 	/* Host publishes avail event idx */
 	bool event;
 
-	/* Number of free buffers */
-	unsigned int num_free;
 	/* Head of free buffer list. */
 	unsigned int free_head;
 	/* Number we've added since last sync. */
@@ -106,9 +104,6 @@ struct vring_virtqueue
 	/* How to notify other side. FIXME: commonalize hcalls! */
 	void (*notify)(struct virtqueue *vq);
 
-	/* Index of the queue */
-	int queue_index;
-
 #ifdef DEBUG
 	/* They're supposed to lock for us. */
 	unsigned int in_use;
@@ -135,6 +130,13 @@ static int vring_add_indirect(struct vring_virtqueue *vq,
 	unsigned head;
 	int i;
 
+	/*
+	 * We require lowmem mappings for the descriptors because
+	 * otherwise virt_to_phys will give us bogus addresses in the
+	 * virtqueue.
+	 */
+	gfp &= ~(__GFP_HIGHMEM | __GFP_HIGH);
+
 	desc = kmalloc((out + in) * sizeof(struct vring_desc), gfp);
 	if (!desc)
 		return -ENOMEM;
@@ -160,7 +162,7 @@ static int vring_add_indirect(struct vring_virtqueue *vq,
 	desc[i-1].next = 0;
 
 	/* We're about to use a buffer */
-	vq->num_free--;
+	vq->vq.num_free--;
 
 	/* Use a single buffer which doesn't continue */
 	head = vq->free_head;
@@ -174,13 +176,6 @@ static int vring_add_indirect(struct vring_virtqueue *vq,
 	return head;
 }
 
-int virtqueue_get_queue_index(struct virtqueue *_vq)
-{
-	struct vring_virtqueue *vq = to_vvq(_vq);
-	return vq->queue_index;
-}
-EXPORT_SYMBOL_GPL(virtqueue_get_queue_index);
-
 /**
  * virtqueue_add_buf - expose buffer to other end
  * @vq: the struct virtqueue we're talking about.
@@ -193,10 +188,7 @@ EXPORT_SYMBOL_GPL(virtqueue_get_queue_index);
  * Caller must ensure we don't call this with other virtqueue operations
  * at the same time (except where noted).
  *
- * Returns remaining capacity of queue or a negative error
- * (ie. ENOSPC).  Note that it only really makes sense to treat all
- * positive return values as "available": indirect buffers mean that
- * we can put an entire sg[] array inside a single queue entry.
+ * Returns zero or a negative error (ie. ENOSPC, ENOMEM).
  */
 int virtqueue_add_buf(struct virtqueue *_vq,
 		      struct scatterlist sg[],
@@ -228,7 +220,7 @@ int virtqueue_add_buf(struct virtqueue *_vq,
 
 	/* If the host supports indirect descriptor tables, and we have multiple
 	 * buffers, then go indirect. FIXME: tune this threshold */
-	if (vq->indirect && (out + in) > 1 && vq->num_free) {
+	if (vq->indirect && (out + in) > 1 && vq->vq.num_free) {
 		head = vring_add_indirect(vq, sg, out, in, gfp);
 		if (likely(head >= 0))
 			goto add_head;
@@ -237,9 +229,9 @@ int virtqueue_add_buf(struct virtqueue *_vq,
 	BUG_ON(out + in > vq->vring.num);
 	BUG_ON(out + in == 0);
 
-	if (vq->num_free < out + in) {
+	if (vq->vq.num_free < out + in) {
 		pr_debug("Can't add buf len %i - avail = %i\n",
-			 out + in, vq->num_free);
+			 out + in, vq->vq.num_free);
 		/* FIXME: for historical reasons, we force a notify here if
 		 * there are outgoing parts to the buffer.  Presumably the
 		 * host should service the ring ASAP. */
@@ -250,7 +242,7 @@ int virtqueue_add_buf(struct virtqueue *_vq,
 	}
 
 	/* We're about to use some buffers from the free list. */
-	vq->num_free -= out + in;
+	vq->vq.num_free -= out + in;
 
 	head = vq->free_head;
 	for (i = vq->free_head; out; i = vq->vring.desc[i].next, out--) {
@@ -296,7 +288,7 @@ int virtqueue_add_buf(struct virtqueue *_vq,
 	pr_debug("Added buffer head %i to %p\n", head, vq);
 	END_USE(vq);
 
-	return vq->num_free;
+	return 0;
 }
 EXPORT_SYMBOL_GPL(virtqueue_add_buf);
 
@@ -393,13 +385,13 @@ static void detach_buf(struct vring_virtqueue *vq, unsigned int head)
 
 	while (vq->vring.desc[i].flags & VRING_DESC_F_NEXT) {
 		i = vq->vring.desc[i].next;
-		vq->num_free++;
+		vq->vq.num_free++;
 	}
 
 	vq->vring.desc[i].next = vq->free_head;
 	vq->free_head = head;
 	/* Plus final descriptor */
-	vq->num_free++;
+	vq->vq.num_free++;
 }
 
 static inline bool more_used(const struct vring_virtqueue *vq)
@@ -599,7 +591,7 @@ void *virtqueue_detach_unused_buf(struct virtqueue *_vq)
 		return buf;
 	}
 	/* That should have freed everything. */
-	BUG_ON(vq->num_free != vq->vring.num);
+	BUG_ON(vq->vq.num_free != vq->vring.num);
 
 	END_USE(vq);
 	return NULL;
@@ -653,12 +645,13 @@ struct virtqueue *vring_new_virtqueue(unsigned int index,
 	vq->vq.callback = callback;
 	vq->vq.vdev = vdev;
 	vq->vq.name = name;
+	vq->vq.num_free = num;
+	vq->vq.index = index;
 	vq->notify = notify;
 	vq->weak_barriers = weak_barriers;
 	vq->broken = false;
 	vq->last_used_idx = 0;
 	vq->num_added = 0;
-	vq->queue_index = index;
 	list_add_tail(&vq->vq.list, &vdev->vqs);
 #ifdef DEBUG
 	vq->in_use = false;
@@ -673,7 +666,6 @@ struct virtqueue *vring_new_virtqueue(unsigned int index,
 		vq->vring.avail->flags |= VRING_AVAIL_F_NO_INTERRUPT;
 
 	/* Put everything in free lists. */
-	vq->num_free = num;
 	vq->free_head = 0;
 	for (i = 0; i < num-1; i++) {
 		vq->vring.desc[i].next = i+1;

include/linux/virtio.h

@@ -16,12 +16,20 @@
  * @name: the name of this virtqueue (mainly for debugging)
  * @vdev: the virtio device this queue was created for.
  * @priv: a pointer for the virtqueue implementation to use.
+ * @index: the zero-based ordinal number for this queue.
+ * @num_free: number of elements we expect to be able to fit.
+ *
+ * A note on @num_free: with indirect buffers, each buffer needs one
+ * element in the queue, otherwise a buffer will need one element per
+ * sg element.
  */
 struct virtqueue {
 	struct list_head list;
 	void (*callback)(struct virtqueue *vq);
 	const char *name;
 	struct virtio_device *vdev;
+	unsigned int index;
+	unsigned int num_free;
 	void *priv;
 };
 
@@ -50,7 +58,11 @@ void *virtqueue_detach_unused_buf(struct virtqueue *vq);
 
 unsigned int virtqueue_get_vring_size(struct virtqueue *vq);
 
-int virtqueue_get_queue_index(struct virtqueue *vq);
+/* FIXME: Obsolete accessor, but required for virtio_net merge. */
+static inline unsigned int virtqueue_get_queue_index(struct virtqueue *vq)
+{
+	return vq->index;
+}
 
 /**
  * virtio_device - representation of a device using virtio
@@ -73,7 +85,11 @@ struct virtio_device {
 	void *priv;
 };
 
-#define dev_to_virtio(dev) container_of(dev, struct virtio_device, dev)
+static inline struct virtio_device *dev_to_virtio(struct device *_dev)
+{
+	return container_of(_dev, struct virtio_device, dev);
+}
+
 int register_virtio_device(struct virtio_device *dev);
 void unregister_virtio_device(struct virtio_device *dev);
 
@@ -103,6 +119,11 @@ struct virtio_driver {
 #endif
 };
 
+static inline struct virtio_driver *drv_to_virtio(struct device_driver *drv)
+{
+	return container_of(drv, struct virtio_driver, driver);
+}
+
 int register_virtio_driver(struct virtio_driver *drv);
 void unregister_virtio_driver(struct virtio_driver *drv);
 #endif /* _LINUX_VIRTIO_H */

include/linux/virtio_scsi.h

+/*
+ * This header is BSD licensed so anyone can use the definitions to implement
+ * compatible drivers/servers.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
 #ifndef _LINUX_VIRTIO_SCSI_H
 #define _LINUX_VIRTIO_SCSI_H
-/* This header is BSD licensed so anyone can use the definitions to implement
- * compatible drivers/servers. */
 
 #define VIRTIO_SCSI_CDB_SIZE   32
 #define VIRTIO_SCSI_SENSE_SIZE 96

include/uapi/linux/virtio_ids.h

@@ -37,5 +37,6 @@
 #define VIRTIO_ID_RPMSG		7 /* virtio remote processor messaging */
 #define VIRTIO_ID_SCSI		8 /* virtio scsi */
 #define VIRTIO_ID_9P		9 /* 9p virtio console */
+#define VIRTIO_ID_RPROC_SERIAL 11 /* virtio remoteproc serial link */
 
 #endif /* _LINUX_VIRTIO_IDS_H */

mm/highmem.c

@@ -105,6 +105,7 @@ struct page *kmap_to_page(void *vaddr)
 
 	return virt_to_page(addr);
 }
+EXPORT_SYMBOL(kmap_to_page);
 
 static void flush_all_zero_pkmaps(void)
 {

net/9p/trans_virtio.c

@@ -39,6 +39,7 @@
 #include <linux/inet.h>
 #include <linux/idr.h>
 #include <linux/file.h>
+#include <linux/highmem.h>
 #include <linux/slab.h>
 #include <net/9p/9p.h>
 #include <linux/parser.h>
@@ -325,7 +326,7 @@ static int p9_get_mapped_pages(struct virtio_chan *chan,
 		int count = nr_pages;
 		while (nr_pages) {
 			s = rest_of_page(data);
-			pages[index++] = virt_to_page(data);
+			pages[index++] = kmap_to_page(data);
 			data += s;
 			nr_pages--;
 		}

tools/lguest/lguest.c

@@ -179,29 +179,6 @@ static struct termios orig_term;
 #define wmb() __asm__ __volatile__("" : : : "memory")
 #define mb() __asm__ __volatile__("" : : : "memory")
 
-/*
- * Convert an iovec element to the given type.
- *
- * This is a fairly ugly trick: we need to know the size of the type and
- * alignment requirement to check the pointer is kosher.  It's also nice to
- * have the name of the type in case we report failure.
- *
- * Typing those three things all the time is cumbersome and error prone, so we
- * have a macro which sets them all up and passes to the real function.
- */
-#define convert(iov, type) \
-	((type *)_convert((iov), sizeof(type), __alignof__(type), #type))
-
-static void *_convert(struct iovec *iov, size_t size, size_t align,
-		      const char *name)
-{
-	if (iov->iov_len != size)
-		errx(1, "Bad iovec size %zu for %s", iov->iov_len, name);
-	if ((unsigned long)iov->iov_base % align != 0)
-		errx(1, "Bad alignment %p for %s", iov->iov_base, name);
-	return iov->iov_base;
-}
-
 /* Wrapper for the last available index.  Makes it easier to change. */
 #define lg_last_avail(vq)	((vq)->last_avail_idx)
 
@@ -228,7 +205,8 @@ static bool iov_empty(const struct iovec iov[], unsigned int num_iov)
 }
 
 /* Take len bytes from the front of this iovec. */
-static void iov_consume(struct iovec iov[], unsigned num_iov, unsigned len)
+static void iov_consume(struct iovec iov[], unsigned num_iov,
+			void *dest, unsigned len)
 {
 	unsigned int i;
 
@@ -236,11 +214,16 @@ static void iov_consume(struct iovec iov[], unsigned num_iov, unsigned len)
 		unsigned int used;
 
 		used = iov[i].iov_len < len ? iov[i].iov_len : len;
+		if (dest) {
+			memcpy(dest, iov[i].iov_base, used);
+			dest += used;
+		}
 		iov[i].iov_base += used;
 		iov[i].iov_len -= used;
 		len -= used;
 	}
-	assert(len == 0);
+	if (len != 0)
+		errx(1, "iovec too short!");
 }
 
 /* The device virtqueue descriptors are followed by feature bitmasks. */
@@ -864,7 +847,7 @@ static void console_output(struct virtqueue *vq)
 			warn("Write to stdout gave %i (%d)", len, errno);
 			break;
 		}
-		iov_consume(iov, out, len);
+		iov_consume(iov, out, NULL, len);
 	}
 
 	/*
@@ -1591,9 +1574,9 @@ static void blk_request(struct virtqueue *vq)
 {
 	struct vblk_info *vblk = vq->dev->priv;
 	unsigned int head, out_num, in_num, wlen;
-	int ret;
+	int ret, i;
 	u8 *in;
-	struct virtio_blk_outhdr *out;
+	struct virtio_blk_outhdr out;
 	struct iovec iov[vq->vring.num];
 	off64_t off;
 
@@ -1603,32 +1586,36 @@ static void blk_request(struct virtqueue *vq)
 	 */
 	head = wait_for_vq_desc(vq, iov, &out_num, &in_num);
 
-	/*
-	 * Every block request should contain at least one output buffer
-	 * (detailing the location on disk and the type of request) and one
-	 * input buffer (to hold the result).
-	 */
-	if (out_num == 0 || in_num == 0)
-		errx(1, "Bad virtblk cmd %u out=%u in=%u",
-		     head, out_num, in_num);
+	/* Copy the output header from the front of the iov (adjusts iov) */
+	iov_consume(iov, out_num, &out, sizeof(out));
+
+	/* Find and trim end of iov input array, for our status byte. */
+	in = NULL;
+	for (i = out_num + in_num - 1; i >= out_num; i--) {
+		if (iov[i].iov_len > 0) {
+			in = iov[i].iov_base + iov[i].iov_len - 1;
+			iov[i].iov_len--;
+			break;
+		}
+	}
+	if (!in)
+		errx(1, "Bad virtblk cmd with no room for status");
 
-	out = convert(&iov[0], struct virtio_blk_outhdr);
-	in = convert(&iov[out_num+in_num-1], u8);
 	/*
 	 * For historical reasons, block operations are expressed in 512 byte
 	 * "sectors".
 	 */
-	off = out->sector * 512;
+	off = out.sector * 512;
 
 	/*
 	 * In general the virtio block driver is allowed to try SCSI commands.
 	 * It'd be nice if we supported eject, for example, but we don't.
 	 */
-	if (out->type & VIRTIO_BLK_T_SCSI_CMD) {
+	if (out.type & VIRTIO_BLK_T_SCSI_CMD) {
 		fprintf(stderr, "Scsi commands unsupported\n");
 		*in = VIRTIO_BLK_S_UNSUPP;
 		wlen = sizeof(*in);
-	} else if (out->type & VIRTIO_BLK_T_OUT) {
+	} else if (out.type & VIRTIO_BLK_T_OUT) {
 		/*
 		 * Write
 		 *
@@ -1636,10 +1623,10 @@ static void blk_request(struct virtqueue *vq)
 		 * if they try to write past end.
 		 */
 		if (lseek64(vblk->fd, off, SEEK_SET) != off)
-			err(1, "Bad seek to sector %llu", out->sector);
+			err(1, "Bad seek to sector %llu", out.sector);
 
-		ret = writev(vblk->fd, iov+1, out_num-1);
-		verbose("WRITE to sector %llu: %i\n", out->sector, ret);
+		ret = writev(vblk->fd, iov, out_num);
+		verbose("WRITE to sector %llu: %i\n", out.sector, ret);
 
 		/*
 		 * Grr... Now we know how long the descriptor they sent was, we
@@ -1655,7 +1642,7 @@ static void blk_request(struct virtqueue *vq)
 
 		wlen = sizeof(*in);
 		*in = (ret >= 0 ? VIRTIO_BLK_S_OK : VIRTIO_BLK_S_IOERR);
-	} else if (out->type & VIRTIO_BLK_T_FLUSH) {
+	} else if (out.type & VIRTIO_BLK_T_FLUSH) {
 		/* Flush */
 		ret = fdatasync(vblk->fd);
 		verbose("FLUSH fdatasync: %i\n", ret);
@@ -1669,10 +1656,9 @@ static void blk_request(struct virtqueue *vq)
 		 * if they try to read past end.
 		 */
 		if (lseek64(vblk->fd, off, SEEK_SET) != off)
-			err(1, "Bad seek to sector %llu", out->sector);
+			err(1, "Bad seek to sector %llu", out.sector);
 
-		ret = readv(vblk->fd, iov+1, in_num-1);
-		verbose("READ from sector %llu: %i\n", out->sector, ret);
+		ret = readv(vblk->fd, iov + out_num, in_num);
 		if (ret >= 0) {
 			wlen = sizeof(*in) + ret;
 			*in = VIRTIO_BLK_S_OK;
@@ -1758,7 +1744,7 @@ static void rng_input(struct virtqueue *vq)
 		len = readv(rng_info->rfd, iov, in_num);
 		if (len <= 0)
 			err(1, "Read from /dev/random gave %i", len);
-		iov_consume(iov, in_num, len);
+		iov_consume(iov, in_num, NULL, len);
 		totlen += len;
 	}
 

tools/virtio/virtio_test.c

@@ -164,7 +164,7 @@ static void run_test(struct vdev_info *dev, struct vq_info *vq,
 				r = virtqueue_add_buf(vq->vq, &sl, 1, 0,
 						      dev->buf + started,
 						      GFP_ATOMIC);
-				if (likely(r >= 0)) {
+				if (likely(r == 0)) {
 					++started;
 					virtqueue_kick(vq->vq);
 				}
@@ -177,7 +177,7 @@ static void run_test(struct vdev_info *dev, struct vq_info *vq,
 				r = 0;
 			}
 
-		} while (r >= 0);
+		} while (r == 0);
 		if (completed == completed_before)
 			++spurious;
 		assert(completed <= bufs);