Merge tag 'to-linus' of git://github.com/rustyrussell/linux

* tag 'to-linus' of git://github.com/rustyrussell/linux: (24 commits)
  lguest: Make sure interrupt is allocated ok by lguest_setup_irq
  lguest: move the lguest tool to the tools directory
  lguest: switch segment-voodoo-numbers to readable symbols
  virtio: balloon: Add freeze, restore handlers to support S4
  virtio: balloon: Move vq initialization into separate function
  virtio: net: Add freeze, restore handlers to support S4
  virtio: net: Move vq and vq buf removal into separate function
  virtio: net: Move vq initialization into separate function
  virtio: blk: Add freeze, restore handlers to support S4
  virtio: blk: Move vq initialization to separate function
  virtio: console: Disable callbacks for virtqueues at start of S4 freeze
  virtio: console: Add freeze and restore handlers to support S4
  virtio: console: Move vq and vq buf removal into separate functions
  virtio: pci: add PM notification handlers for restore, freeze, thaw, poweroff
  virtio: pci: switch to new PM API
  virtio_blk: fix config handler race
  virtio: add debugging if driver doesn't kick.
  virtio: expose added descriptors immediately.
  virtio: avoid modulus operation.
  virtio: support unlocked queue kick
  ...

arch/x86/lguest/boot.c

@@ -856,18 +856,23 @@ static void __init lguest_init_IRQ(void)
 }
 
 /*
- * With CONFIG_SPARSE_IRQ, interrupt descriptors are allocated as-needed, so
- * rather than set them in lguest_init_IRQ we are called here every time an
- * lguest device needs an interrupt.
- *
- * FIXME: irq_alloc_desc_at() can fail due to lack of memory, we should
- * pass that up!
+ * Interrupt descriptors are allocated as-needed, but low-numbered ones are
+ * reserved by the generic x86 code.  So we ignore irq_alloc_desc_at if it
+ * tells us the irq is already used: other errors (ie. ENOMEM) we take
+ * seriously.
  */
-void lguest_setup_irq(unsigned int irq)
+int lguest_setup_irq(unsigned int irq)
 {
-	irq_alloc_desc_at(irq, 0);
+	int err;
+
+	/* Returns -ve error or vector number. */
+	err = irq_alloc_desc_at(irq, 0);
+	if (err < 0 && err != -EEXIST)
+		return err;
+
 	irq_set_chip_and_handler_name(irq, &lguest_irq_controller,
 				      handle_level_irq, "level");
+	return 0;
 }
 
 /*

drivers/block/virtio_blk.c

@@ -4,6 +4,7 @@
 #include <linux/blkdev.h>
 #include <linux/hdreg.h>
 #include <linux/module.h>
+#include <linux/mutex.h>
 #include <linux/virtio.h>
 #include <linux/virtio_blk.h>
 #include <linux/scatterlist.h>
@@ -36,6 +37,12 @@ struct virtio_blk
 	/* Process context for config space updates */
 	struct work_struct config_work;
 
+	/* Lock for config space updates */
+	struct mutex config_lock;
+
+	/* enable config space updates */
+	bool config_enable;
+
 	/* What host tells us, plus 2 for header & tailer. */
 	unsigned int sg_elems;
 
@@ -172,7 +179,7 @@ static bool do_req(struct request_queue *q, struct virtio_blk *vblk,
 		}
 	}
 
-	if (virtqueue_add_buf(vblk->vq, vblk->sg, out, in, vbr) < 0) {
+	if (virtqueue_add_buf(vblk->vq, vblk->sg, out, in, vbr, GFP_ATOMIC)<0) {
 		mempool_free(vbr, vblk->pool);
 		return false;
 	}
@@ -318,6 +325,10 @@ static void virtblk_config_changed_work(struct work_struct *work)
 	char cap_str_2[10], cap_str_10[10];
 	u64 capacity, size;
 
+	mutex_lock(&vblk->config_lock);
+	if (!vblk->config_enable)
+		goto done;
+
 	/* Host must always specify the capacity. */
 	vdev->config->get(vdev, offsetof(struct virtio_blk_config, capacity),
 			  &capacity, sizeof(capacity));
@@ -340,6 +351,8 @@ static void virtblk_config_changed_work(struct work_struct *work)
 		  cap_str_10, cap_str_2);
 
 	set_capacity(vblk->disk, capacity);
+done:
+	mutex_unlock(&vblk->config_lock);
 }
 
 static void virtblk_config_changed(struct virtio_device *vdev)
@@ -349,6 +362,18 @@ static void virtblk_config_changed(struct virtio_device *vdev)
 	queue_work(virtblk_wq, &vblk->config_work);
 }
 
+static int init_vq(struct virtio_blk *vblk)
+{
+	int err = 0;
+
+	/* We expect one virtqueue, for output. */
+	vblk->vq = virtio_find_single_vq(vblk->vdev, blk_done, "requests");
+	if (IS_ERR(vblk->vq))
+		err = PTR_ERR(vblk->vq);
+
+	return err;
+}
+
 static int __devinit virtblk_probe(struct virtio_device *vdev)
 {
 	struct virtio_blk *vblk;
@@ -388,14 +413,13 @@ static int __devinit virtblk_probe(struct virtio_device *vdev)
 	vblk->vdev = vdev;
 	vblk->sg_elems = sg_elems;
 	sg_init_table(vblk->sg, vblk->sg_elems);
+	mutex_init(&vblk->config_lock);
 	INIT_WORK(&vblk->config_work, virtblk_config_changed_work);
+	vblk->config_enable = true;
 
-	/* We expect one virtqueue, for output. */
-	vblk->vq = virtio_find_single_vq(vdev, blk_done, "requests");
-	if (IS_ERR(vblk->vq)) {
-		err = PTR_ERR(vblk->vq);
+	err = init_vq(vblk);
+	if (err)
 		goto out_free_vblk;
-	}
 
 	vblk->pool = mempool_create_kmalloc_pool(1,sizeof(struct virtblk_req));
 	if (!vblk->pool) {
@@ -542,14 +566,19 @@ static void __devexit virtblk_remove(struct virtio_device *vdev)
 	struct virtio_blk *vblk = vdev->priv;
 	int index = vblk->index;
 
-	flush_work(&vblk->config_work);
+	/* Prevent config work handler from accessing the device. */
+	mutex_lock(&vblk->config_lock);
+	vblk->config_enable = false;
+	mutex_unlock(&vblk->config_lock);
 
 	/* Nothing should be pending. */
 	BUG_ON(!list_empty(&vblk->reqs));
 
 	/* Stop all the virtqueues. */
 	vdev->config->reset(vdev);
 
+	flush_work(&vblk->config_work);
+
 	del_gendisk(vblk->disk);
 	blk_cleanup_queue(vblk->disk->queue);
 	put_disk(vblk->disk);
@@ -559,6 +588,46 @@ static void __devexit virtblk_remove(struct virtio_device *vdev)
 	ida_simple_remove(&vd_index_ida, index);
 }
 
+#ifdef CONFIG_PM
+static int virtblk_freeze(struct virtio_device *vdev)
+{
+	struct virtio_blk *vblk = vdev->priv;
+
+	/* Ensure we don't receive any more interrupts */
+	vdev->config->reset(vdev);
+
+	/* Prevent config work handler from accessing the device. */
+	mutex_lock(&vblk->config_lock);
+	vblk->config_enable = false;
+	mutex_unlock(&vblk->config_lock);
+
+	flush_work(&vblk->config_work);
+
+	spin_lock_irq(vblk->disk->queue->queue_lock);
+	blk_stop_queue(vblk->disk->queue);
+	spin_unlock_irq(vblk->disk->queue->queue_lock);
+	blk_sync_queue(vblk->disk->queue);
+
+	vdev->config->del_vqs(vdev);
+	return 0;
+}
+
+static int virtblk_restore(struct virtio_device *vdev)
+{
+	struct virtio_blk *vblk = vdev->priv;
+	int ret;
+
+	vblk->config_enable = true;
+	ret = init_vq(vdev->priv);
+	if (!ret) {
+		spin_lock_irq(vblk->disk->queue->queue_lock);
+		blk_start_queue(vblk->disk->queue);
+		spin_unlock_irq(vblk->disk->queue->queue_lock);
+	}
+	return ret;
+}
+#endif
+
 static const struct virtio_device_id id_table[] = {
 	{ VIRTIO_ID_BLOCK, VIRTIO_DEV_ANY_ID },
 	{ 0 },
@@ -584,6 +653,10 @@ static struct virtio_driver __refdata virtio_blk = {
 	.probe			= virtblk_probe,
 	.remove			= __devexit_p(virtblk_remove),
 	.config_changed		= virtblk_config_changed,
+#ifdef CONFIG_PM
+	.freeze			= virtblk_freeze,
+	.restore		= virtblk_restore,
+#endif
 };
 
 static int __init init(void)

drivers/char/hw_random/virtio-rng.c

@@ -47,7 +47,7 @@ static void register_buffer(u8 *buf, size_t size)
 	sg_init_one(&sg, buf, size);
 
 	/* There should always be room for one buffer. */
-	if (virtqueue_add_buf(vq, &sg, 0, 1, buf) < 0)
+	if (virtqueue_add_buf(vq, &sg, 0, 1, buf, GFP_KERNEL) < 0)
 		BUG();
 
 	virtqueue_kick(vq);