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

Pull virtio updates from Rusty Russell:
 "One cc: stable commit, the rest are a series of minor cleanups which
  have been sitting in MST's tree during my vacation.  I changed a
  function name and made one trivial change, then they spent two days in
  linux-next"

* tag 'virtio-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: (25 commits)
  virtio-rng: refactor probe error handling
  virtio_scsi: drop scan callback
  virtio_balloon: enable VQs early on restore
  virtio_scsi: fix race on device removal
  virito_scsi: use freezable WQ for events
  virtio_net: enable VQs early on restore
  virtio_console: enable VQs early on restore
  virtio_scsi: enable VQs early on restore
  virtio_blk: enable VQs early on restore
  virtio_scsi: move kick event out from virtscsi_init
  virtio_net: fix use after free on allocation failure
  9p/trans_virtio: enable VQs early
  virtio_console: enable VQs early
  virtio_blk: enable VQs early
  virtio_net: enable VQs early
  virtio: add API to enable VQs early
  virtio_net: minor cleanup
  virtio-net: drop config_mutex
  virtio_net: drop config_enable
  virtio-blk: drop config_mutex
  ...

4 files changed, 110 insertions, 35 deletions

diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
index fed0ce198ae3..df598dd8c5c8 100644
--- a/drivers/virtio/virtio.c
+++ b/drivers/virtio/virtio.c
@@ -117,6 +117,43 @@ void virtio_check_driver_offered_feature(const struct virtio_device *vdev,
 }
 EXPORT_SYMBOL_GPL(virtio_check_driver_offered_feature);
 
+static void __virtio_config_changed(struct virtio_device *dev)
+{
+        struct virtio_driver *drv = drv_to_virtio(dev->dev.driver);
+
+        if (!dev->config_enabled)
+                dev->config_change_pending = true;
+        else if (drv && drv->config_changed)
+                drv->config_changed(dev);
+}
+
+void virtio_config_changed(struct virtio_device *dev)
+{
+        unsigned long flags;
+
+        spin_lock_irqsave(&dev->config_lock, flags);
+        __virtio_config_changed(dev);
+        spin_unlock_irqrestore(&dev->config_lock, flags);
+}
+EXPORT_SYMBOL_GPL(virtio_config_changed);
+
+static void virtio_config_disable(struct virtio_device *dev)
+{
+        spin_lock_irq(&dev->config_lock);
+        dev->config_enabled = false;
+        spin_unlock_irq(&dev->config_lock);
+}
+
+static void virtio_config_enable(struct virtio_device *dev)
+{
+        spin_lock_irq(&dev->config_lock);
+        dev->config_enabled = true;
+        if (dev->config_change_pending)
+                __virtio_config_changed(dev);
+        dev->config_change_pending = false;
+        spin_unlock_irq(&dev->config_lock);
+}
+
 static int virtio_dev_probe(struct device *_d)
 {
         int err, i;
@@ -153,6 +190,8 @@ static int virtio_dev_probe(struct device *_d)
                 add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);
                 if (drv->scan)
                         drv->scan(dev);
+
+                virtio_config_enable(dev);
         }
 
         return err;
@@ -163,6 +202,8 @@ static int virtio_dev_remove(struct device *_d)
         struct virtio_device *dev = dev_to_virtio(_d);
         struct virtio_driver *drv = drv_to_virtio(dev->dev.driver);
 
+        virtio_config_disable(dev);
+
         drv->remove(dev);
 
         /* Driver should have reset device. */
@@ -211,6 +252,10 @@ int register_virtio_device(struct virtio_device *dev)
         dev->index = err;
         dev_set_name(&dev->dev, "virtio%u", dev->index);
 
+        spin_lock_init(&dev->config_lock);
+        dev->config_enabled = false;
+        dev->config_change_pending = false;
+
         /* We always start by resetting the device, in case a previous
          * driver messed it up.  This also tests that code path a little. */
         dev->config->reset(dev);
@@ -239,6 +284,64 @@ void unregister_virtio_device(struct virtio_device *dev)
 }
 EXPORT_SYMBOL_GPL(unregister_virtio_device);
 
+#ifdef CONFIG_PM_SLEEP
+int virtio_device_freeze(struct virtio_device *dev)
+{
+        struct virtio_driver *drv = drv_to_virtio(dev->dev.driver);
+
+        virtio_config_disable(dev);
+
+        dev->failed = dev->config->get_status(dev) & VIRTIO_CONFIG_S_FAILED;
+
+        if (drv && drv->freeze)
+                return drv->freeze(dev);
+
+        return 0;
+}
+EXPORT_SYMBOL_GPL(virtio_device_freeze);
+
+int virtio_device_restore(struct virtio_device *dev)
+{
+        struct virtio_driver *drv = drv_to_virtio(dev->dev.driver);
+
+        /* We always start by resetting the device, in case a previous
+         * driver messed it up. */
+        dev->config->reset(dev);
+
+        /* Acknowledge that we've seen the device. */
+        add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE);
+
+        /* Maybe driver failed before freeze.
+         * Restore the failed status, for debugging. */
+        if (dev->failed)
+                add_status(dev, VIRTIO_CONFIG_S_FAILED);
+
+        if (!drv)
+                return 0;
+
+        /* We have a driver! */
+        add_status(dev, VIRTIO_CONFIG_S_DRIVER);
+
+        dev->config->finalize_features(dev);
+
+        if (drv->restore) {
+                int ret = drv->restore(dev);
+                if (ret) {
+                        add_status(dev, VIRTIO_CONFIG_S_FAILED);
+                        return ret;
+                }
+        }
+
+        /* Finally, tell the device we're all set */
+        add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);
+
+        virtio_config_enable(dev);
+
+        return 0;
+}
+EXPORT_SYMBOL_GPL(virtio_device_restore);
+#endif
+
 static int virtio_init(void)
 {
         if (bus_register(&virtio_bus) != 0)
diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c
index f893148a107b..c9703d4d6f67 100644
--- a/drivers/virtio/virtio_balloon.c
+++ b/drivers/virtio/virtio_balloon.c
@@ -504,6 +504,8 @@ static int virtballoon_restore(struct virtio_device *vdev)
         if (ret)
                 return ret;
 
+        virtio_device_ready(vdev);
+
         fill_balloon(vb, towards_target(vb));
         update_balloon_size(vb);
         return 0;
diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.c
index c600ccfd6922..ef9a1650bb80 100644
--- a/drivers/virtio/virtio_mmio.c
+++ b/drivers/virtio/virtio_mmio.c
@@ -234,8 +234,6 @@ static irqreturn_t vm_interrupt(int irq, void *opaque)
 {
         struct virtio_mmio_device *vm_dev = opaque;
         struct virtio_mmio_vq_info *info;
-        struct virtio_driver *vdrv = container_of(vm_dev->vdev.dev.driver,
-                        struct virtio_driver, driver);
         unsigned long status;
         unsigned long flags;
         irqreturn_t ret = IRQ_NONE;
@@ -244,9 +242,8 @@ static irqreturn_t vm_interrupt(int irq, void *opaque)
         status = readl(vm_dev->base + VIRTIO_MMIO_INTERRUPT_STATUS);
         writel(status, vm_dev->base + VIRTIO_MMIO_INTERRUPT_ACK);
 
-        if (unlikely(status & VIRTIO_MMIO_INT_CONFIG)
-                        && vdrv && vdrv->config_changed) {
-                vdrv->config_changed(&vm_dev->vdev);
+        if (unlikely(status & VIRTIO_MMIO_INT_CONFIG)) {
+                virtio_config_changed(&vm_dev->vdev);
                 ret = IRQ_HANDLED;
         }
 
diff --git a/drivers/virtio/virtio_pci.c b/drivers/virtio/virtio_pci.c
index 3d1463c6b120..d34ebfa604f3 100644
--- a/drivers/virtio/virtio_pci.c
+++ b/drivers/virtio/virtio_pci.c
@@ -57,9 +57,6 @@ struct virtio_pci_device
         /* Vectors allocated, excluding per-vq vectors if any */
         unsigned msix_used_vectors;
 
-        /* Status saved during hibernate/restore */
-        u8 saved_status;
-
         /* Whether we have vector per vq */
         bool per_vq_vectors;
 };
@@ -211,12 +208,8 @@ static bool vp_notify(struct virtqueue *vq)
 static irqreturn_t vp_config_changed(int irq, void *opaque)
 {
         struct virtio_pci_device *vp_dev = opaque;
-        struct virtio_driver *drv;
-        drv = container_of(vp_dev->vdev.dev.driver,
-                           struct virtio_driver, driver);
 
-        if (drv && drv->config_changed)
-                drv->config_changed(&vp_dev->vdev);
+        virtio_config_changed(&vp_dev->vdev);
         return IRQ_HANDLED;
 }
 
@@ -768,16 +761,9 @@ static int virtio_pci_freeze(struct device *dev)
 {
         struct pci_dev *pci_dev = to_pci_dev(dev);
         struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev);
-        struct virtio_driver *drv;
         int ret;
 
-        drv = container_of(vp_dev->vdev.dev.driver,
-                           struct virtio_driver, driver);
-
-        ret = 0;
-        vp_dev->saved_status = vp_get_status(&vp_dev->vdev);
-        if (drv && drv->freeze)
-                ret = drv->freeze(&vp_dev->vdev);
+        ret = virtio_device_freeze(&vp_dev->vdev);
 
         if (!ret)
                 pci_disable_device(pci_dev);
@@ -788,27 +774,14 @@ static int virtio_pci_restore(struct device *dev)
 {
         struct pci_dev *pci_dev = to_pci_dev(dev);
         struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev);
-        struct virtio_driver *drv;
         int ret;
 
-        drv = container_of(vp_dev->vdev.dev.driver,
-                           struct virtio_driver, driver);
-
         ret = pci_enable_device(pci_dev);
         if (ret)
                 return ret;
 
         pci_set_master(pci_dev);
-        vp_finalize_features(&vp_dev->vdev);
-
-        if (drv && drv->restore)
-                ret = drv->restore(&vp_dev->vdev);
-
-        /* Finally, tell the device we're all set */
-        if (!ret)
-                vp_set_status(&vp_dev->vdev, vp_dev->saved_status);
-
-        return ret;
+        return virtio_device_restore(&vp_dev->vdev);
 }
 
 static const struct dev_pm_ops virtio_pci_pm_ops = {