virtio: add names to virtqueue struct, mapping from devices to queues.

Add a linked list of all virtqueues for a virtio device: this helps for
debugging and is also needed for upcoming interface change.

Also, add a "name" field for clearer debug messages.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

14 files changed, 56 insertions, 31 deletions

diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index c0facaa55cf4..db55a50d9f6a 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -288,7 +288,7 @@ static int virtblk_probe(struct virtio_device *vdev)
         sg_init_table(vblk->sg, vblk->sg_elems);
 
         /* We expect one virtqueue, for output. */
-        vblk->vq = vdev->config->find_vq(vdev, 0, blk_done);
+        vblk->vq = vdev->config->find_vq(vdev, 0, blk_done, "requests");
         if (IS_ERR(vblk->vq)) {
                 err = PTR_ERR(vblk->vq);
                 goto out_free_vblk;
diff --git a/drivers/char/hw_random/virtio-rng.c b/drivers/char/hw_random/virtio-rng.c
index 86e83f883139..2aeafcea95fe 100644
--- a/drivers/char/hw_random/virtio-rng.c
+++ b/drivers/char/hw_random/virtio-rng.c
@@ -94,7 +94,7 @@ static int virtrng_probe(struct virtio_device *vdev)
         int err;
 
         /* We expect a single virtqueue. */
-        vq = vdev->config->find_vq(vdev, 0, random_recv_done);
+        vq = vdev->config->find_vq(vdev, 0, random_recv_done, "input");
         if (IS_ERR(vq))
                 return PTR_ERR(vq);
 
diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index ff6f5a4b58fb..58684e4a0814 100644
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -202,13 +202,13 @@ static int __devinit virtcons_probe(struct virtio_device *dev)
         /* Find the input queue. */
         /* FIXME: This is why we want to wean off hvc: we do nothing
          * when input comes in. */
-        in_vq = vdev->config->find_vq(vdev, 0, hvc_handle_input);
+        in_vq = vdev->config->find_vq(vdev, 0, hvc_handle_input, "input");
         if (IS_ERR(in_vq)) {
                 err = PTR_ERR(in_vq);
                 goto free;
         }
 
-        out_vq = vdev->config->find_vq(vdev, 1, NULL);
+        out_vq = vdev->config->find_vq(vdev, 1, NULL, "output");
         if (IS_ERR(out_vq)) {
                 err = PTR_ERR(out_vq);
                 goto free_in_vq;
diff --git a/drivers/lguest/lguest_device.c b/drivers/lguest/lguest_device.c
index df44d962626d..4babed899d59 100644
--- a/drivers/lguest/lguest_device.c
+++ b/drivers/lguest/lguest_device.c
@@ -228,7 +228,8 @@ extern void lguest_setup_irq(unsigned int irq);
  * function. */
 static struct virtqueue *lg_find_vq(struct virtio_device *vdev,
                                     unsigned index,
-                                    void (*callback)(struct virtqueue *vq))
+                                    void (*callback)(struct virtqueue *vq),
+                                    const char *name)
 {
         struct lguest_device *ldev = to_lgdev(vdev);
         struct lguest_vq_info *lvq;
@@ -263,7 +264,7 @@ static struct virtqueue *lg_find_vq(struct virtio_device *vdev,
         /* OK, tell virtio_ring.c to set up a virtqueue now we know its size
          * and we've got a pointer to its pages. */
         vq = vring_new_virtqueue(lvq->config.num, LGUEST_VRING_ALIGN,
-                                 vdev, lvq->pages, lg_notify, callback);
+                                 vdev, lvq->pages, lg_notify, callback, name);
         if (!vq) {
                 err = -ENOMEM;
                 goto unmap;
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 4d1d47953fc6..be3b734ff5a1 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -906,20 +906,20 @@ static int virtnet_probe(struct virtio_device *vdev)
                 vi->mergeable_rx_bufs = true;
 
         /* We expect two virtqueues, receive then send. */
-        vi->rvq = vdev->config->find_vq(vdev, 0, skb_recv_done);
+        vi->rvq = vdev->config->find_vq(vdev, 0, skb_recv_done, "input");
         if (IS_ERR(vi->rvq)) {
                 err = PTR_ERR(vi->rvq);
                 goto free;
         }
 
-        vi->svq = vdev->config->find_vq(vdev, 1, skb_xmit_done);
+        vi->svq = vdev->config->find_vq(vdev, 1, skb_xmit_done, "output");
         if (IS_ERR(vi->svq)) {
                 err = PTR_ERR(vi->svq);
                 goto free_recv;
         }
 
         if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ)) {
-                vi->cvq = vdev->config->find_vq(vdev, 2, NULL);
+                vi->cvq = vdev->config->find_vq(vdev, 2, NULL, "control");
                 if (IS_ERR(vi->cvq)) {
                         err = PTR_ERR(vi->svq);
                         goto free_send;
diff --git a/drivers/s390/kvm/kvm_virtio.c b/drivers/s390/kvm/kvm_virtio.c
index cbc8566fab70..ba8995fbf041 100644
--- a/drivers/s390/kvm/kvm_virtio.c
+++ b/drivers/s390/kvm/kvm_virtio.c
@@ -173,8 +173,9 @@ static void kvm_notify(struct virtqueue *vq)
  * this device and sets it up.
  */
 static struct virtqueue *kvm_find_vq(struct virtio_device *vdev,
-                                    unsigned index,
-                                    void (*callback)(struct virtqueue *vq))
+                                     unsigned index,
+                                     void (*callback)(struct virtqueue *vq),
+                                     const char *name)
 {
         struct kvm_device *kdev = to_kvmdev(vdev);
         struct kvm_vqconfig *config;
@@ -194,7 +195,7 @@ static struct virtqueue *kvm_find_vq(struct virtio_device *vdev,
 
         vq = vring_new_virtqueue(config->num, KVM_S390_VIRTIO_RING_ALIGN,
                                  vdev, (void *) config->address,
-                                 kvm_notify, callback);
+                                 kvm_notify, callback, name);
         if (!vq) {
                 err = -ENOMEM;
                 goto unmap;
diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
index 6b6810364860..3f52c767dfe9 100644
--- a/drivers/virtio/virtio.c
+++ b/drivers/virtio/virtio.c
@@ -186,6 +186,8 @@ int register_virtio_device(struct virtio_device *dev)
         /* Acknowledge that we've seen the device. */
         add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE);
 
+        INIT_LIST_HEAD(&dev->vqs);
+
         /* device_register() causes the bus infrastructure to look for a
          * matching driver. */
         err = device_register(&dev->dev);
diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c
index 9c76a061a04d..0fa73b4d18b0 100644
--- a/drivers/virtio/virtio_balloon.c
+++ b/drivers/virtio/virtio_balloon.c
@@ -218,13 +218,13 @@ static int virtballoon_probe(struct virtio_device *vdev)
         vb->vdev = vdev;
 
         /* We expect two virtqueues. */
-        vb->inflate_vq = vdev->config->find_vq(vdev, 0, balloon_ack);
+        vb->inflate_vq = vdev->config->find_vq(vdev, 0, balloon_ack, "inflate");
         if (IS_ERR(vb->inflate_vq)) {
                 err = PTR_ERR(vb->inflate_vq);
                 goto out_free_vb;
         }
 
-        vb->deflate_vq = vdev->config->find_vq(vdev, 1, balloon_ack);
+        vb->deflate_vq = vdev->config->find_vq(vdev, 1, balloon_ack, "deflate");
         if (IS_ERR(vb->deflate_vq)) {
                 err = PTR_ERR(vb->deflate_vq);
                 goto out_del_inflate_vq;
diff --git a/drivers/virtio/virtio_pci.c b/drivers/virtio/virtio_pci.c
index 330aacbdec1f..be4047abd5ba 100644
--- a/drivers/virtio/virtio_pci.c
+++ b/drivers/virtio/virtio_pci.c
@@ -208,7 +208,8 @@ static irqreturn_t vp_interrupt(int irq, void *opaque)
 
 /* the config->find_vq() implementation */
 static struct virtqueue *vp_find_vq(struct virtio_device *vdev, unsigned index,
-                                    void (*callback)(struct virtqueue *vq))
+                                    void (*callback)(struct virtqueue *vq),
+                                    const char *name)
 {
         struct virtio_pci_device *vp_dev = to_vp_device(vdev);
         struct virtio_pci_vq_info *info;
@@ -247,7 +248,7 @@ static struct virtqueue *vp_find_vq(struct virtio_device *vdev, unsigned index,
 
         /* create the vring */
         vq = vring_new_virtqueue(info->num, VIRTIO_PCI_VRING_ALIGN,
-                                 vdev, info->queue, vp_notify, callback);
+                                 vdev, info->queue, vp_notify, callback, name);
         if (!vq) {
                 err = -ENOMEM;
                 goto out_activate_queue;
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 5c52369ab9bb..579fa693d5d0 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -23,21 +23,30 @@
 
 #ifdef DEBUG
 /* For development, we want to crash whenever the ring is screwed. */
-#define BAD_RING(_vq, fmt...)                   \
-        do { dev_err(&(_vq)->vq.vdev->dev, fmt); BUG(); } while(0)
+#define BAD_RING(_vq, fmt, args...)                             \
+        do {                                                    \
+                dev_err(&(_vq)->vq.vdev->dev,                   \
+                        "%s:"fmt, (_vq)->vq.name, ##args);      \
+                BUG();                                          \
+        } while (0)
 /* Caller is supposed to guarantee no reentry. */
 #define START_USE(_vq)                                          \
         do {                                                    \
                 if ((_vq)->in_use)                              \
-                        panic("in_use = %i\n", (_vq)->in_use);  \
+                        panic("%s:in_use = %i\n",               \
+                              (_vq)->vq.name, (_vq)->in_use);   \
                 (_vq)->in_use = __LINE__;                       \
                 mb();                                           \
-        } while(0)
+        } while (0)
 #define END_USE(_vq) \
         do { BUG_ON(!(_vq)->in_use); (_vq)->in_use = 0; mb(); } while(0)
 #else
-#define BAD_RING(_vq, fmt...)                   \
-        do { dev_err(&_vq->vq.vdev->dev, fmt); (_vq)->broken = true; } while(0)
+#define BAD_RING(_vq, fmt, args...)                             \
+        do {                                                    \
+                dev_err(&_vq->vq.vdev->dev,                     \
+                        "%s:"fmt, (_vq)->vq.name, ##args);      \
+                (_vq)->broken = true;                           \
+        } while (0)
 #define START_USE(vq)
 #define END_USE(vq)
 #endif
@@ -284,7 +293,8 @@ struct virtqueue *vring_new_virtqueue(unsigned int num,
                                       struct virtio_device *vdev,
                                       void *pages,
                                       void (*notify)(struct virtqueue *),
-                                      void (*callback)(struct virtqueue *))
+                                      void (*callback)(struct virtqueue *),
+                                      const char *name)
 {
         struct vring_virtqueue *vq;
         unsigned int i;
@@ -303,10 +313,12 @@ struct virtqueue *vring_new_virtqueue(unsigned int num,
         vq->vq.callback = callback;
         vq->vq.vdev = vdev;
         vq->vq.vq_ops = &vring_vq_ops;
+        vq->vq.name = name;
         vq->notify = notify;
         vq->broken = false;
         vq->last_used_idx = 0;
         vq->num_added = 0;
+        list_add_tail(&vq->vq.list, &vdev->vqs);
 #ifdef DEBUG
         vq->in_use = false;
 #endif
@@ -327,6 +339,7 @@ EXPORT_SYMBOL_GPL(vring_new_virtqueue);
 
 void vring_del_virtqueue(struct virtqueue *vq)
 {
+        list_del(&vq->list);
         kfree(to_vvq(vq));
 }
 EXPORT_SYMBOL_GPL(vring_del_virtqueue);
diff --git a/include/linux/virtio.h b/include/linux/virtio.h
index 9410394bbf96..4fca4f5440ba 100644
--- a/include/linux/virtio.h
+++ b/include/linux/virtio.h
@@ -10,14 +10,17 @@
 
 /**
  * virtqueue - a queue to register buffers for sending or receiving.
+ * @list: the chain of virtqueues for this device
  * @callback: the function to call when buffers are consumed (can be NULL).
+ * @name: the name of this virtqueue (mainly for debugging)
  * @vdev: the virtio device this queue was created for.
  * @vq_ops: the operations for this virtqueue (see below).
  * @priv: a pointer for the virtqueue implementation to use.
  */
-struct virtqueue
-{
+struct virtqueue {
+        struct list_head list;
         void (*callback)(struct virtqueue *vq);
+        const char *name;
         struct virtio_device *vdev;
         struct virtqueue_ops *vq_ops;
         void *priv;
@@ -76,15 +79,16 @@ struct virtqueue_ops {
  * @dev: underlying device.
  * @id: the device type identification (used to match it with a driver).
  * @config: the configuration ops for this device.
+ * @vqs: the list of virtqueues for this device.
  * @features: the features supported by both driver and device.
  * @priv: private pointer for the driver's use.
  */
-struct virtio_device
-{
+struct virtio_device {
         int index;
         struct device dev;
         struct virtio_device_id id;
         struct virtio_config_ops *config;
+        struct list_head vqs;
         /* Note that this is a Linux set_bit-style bitmap. */
         unsigned long features[1];
         void *priv;
diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h
index bf8ec283b232..9fae274751e0 100644
--- a/include/linux/virtio_config.h
+++ b/include/linux/virtio_config.h
@@ -55,7 +55,8 @@
  * @find_vq: find a virtqueue and instantiate it.
  *      vdev: the virtio_device
  *      index: the 0-based virtqueue number in case there's more than one.
- *      callback: the virqtueue callback
+ *      callback: the virtqueue callback
+ *      name: the virtqueue name (mainly for debugging)
  *      Returns the new virtqueue or ERR_PTR() (eg. -ENOENT).
  * @del_vq: free a virtqueue found by find_vq().
  * @get_features: get the array of feature bits for this device.
@@ -77,7 +78,8 @@ struct virtio_config_ops
         void (*reset)(struct virtio_device *vdev);
         struct virtqueue *(*find_vq)(struct virtio_device *vdev,
                                      unsigned index,
-                                     void (*callback)(struct virtqueue *));
+                                     void (*callback)(struct virtqueue *),
+                                     const char *name);
         void (*del_vq)(struct virtqueue *vq);
         u32 (*get_features)(struct virtio_device *vdev);
         void (*finalize_features)(struct virtio_device *vdev);
diff --git a/include/linux/virtio_ring.h b/include/linux/virtio_ring.h
index 71e03722fb59..166c519689de 100644
--- a/include/linux/virtio_ring.h
+++ b/include/linux/virtio_ring.h
@@ -119,7 +119,8 @@ struct virtqueue *vring_new_virtqueue(unsigned int num,
                                       struct virtio_device *vdev,
                                       void *pages,
                                       void (*notify)(struct virtqueue *vq),
-                                      void (*callback)(struct virtqueue *vq));
+                                      void (*callback)(struct virtqueue *vq),
+                                      const char *name);
 void vring_del_virtqueue(struct virtqueue *vq);
 /* Filter out transport-specific feature bits. */
 void vring_transport_features(struct virtio_device *vdev);
diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c
index bb8579a141a8..ab8791f9aba8 100644
--- a/net/9p/trans_virtio.c
+++ b/net/9p/trans_virtio.c
@@ -246,7 +246,7 @@ static int p9_virtio_probe(struct virtio_device *vdev)
         chan->vdev = vdev;
 
         /* We expect one virtqueue, for requests. */
-        chan->vq = vdev->config->find_vq(vdev, 0, req_done);
+        chan->vq = vdev->config->find_vq(vdev, 0, req_done, "requests");
         if (IS_ERR(chan->vq)) {
                 err = PTR_ERR(chan->vq);
                 goto out_free_vq;