Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost

pull virtio/vhost fixes from Michael Tsirkin:
 "This fixes a couple of bugs triggered by hot-unplug of virtio devices,
  as well as a regression in vhost-net"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  vhost/net: length miscalculation
  virtio_pci: document why we defer kfree
  virtio_pci: defer kfree until release callback
  virtio_pci: device-specific release callback
  virtio: make del_vqs idempotent

4 files changed, 13 insertions, 12 deletions

diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 14419a8ccbb6..d415d69dc237 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -538,7 +538,7 @@ static int get_rx_bufs(struct vhost_virtqueue *vq,
                 ++headcount;
                 seg += in;
         }
-        heads[headcount - 1].len = cpu_to_vhost32(vq, len - datalen);
+        heads[headcount - 1].len = cpu_to_vhost32(vq, len + datalen);
         *iovcount = seg;
         if (unlikely(log))
                 *log_num = nlogs;
diff --git a/drivers/virtio/virtio_pci_common.c b/drivers/virtio/virtio_pci_common.c
index 2ef9529809d8..9756f21b809e 100644
--- a/drivers/virtio/virtio_pci_common.c
+++ b/drivers/virtio/virtio_pci_common.c
@@ -282,6 +282,7 @@ void vp_del_vqs(struct virtio_device *vdev)
 
         vp_free_vectors(vdev);
         kfree(vp_dev->vqs);
+        vp_dev->vqs = NULL;
 }
 
 static int vp_try_to_find_vqs(struct virtio_device *vdev, unsigned nvqs,
@@ -421,15 +422,6 @@ int vp_set_vq_affinity(struct virtqueue *vq, int cpu)
         return 0;
 }
 
-void virtio_pci_release_dev(struct device *_d)
-{
-        /*
-         * No need for a release method as we allocate/free
-         * all devices together with the pci devices.
-         * Provide an empty one to avoid getting a warning from core.
-         */
-}
-
 #ifdef CONFIG_PM_SLEEP
 static int virtio_pci_freeze(struct device *dev)
 {
diff --git a/drivers/virtio/virtio_pci_common.h b/drivers/virtio/virtio_pci_common.h
index adddb647b21d..5a497289b7e9 100644
--- a/drivers/virtio/virtio_pci_common.h
+++ b/drivers/virtio/virtio_pci_common.h
@@ -126,7 +126,6 @@ const char *vp_bus_name(struct virtio_device *vdev);
  * - ignore the affinity request if we're using INTX
  */
 int vp_set_vq_affinity(struct virtqueue *vq, int cpu);
-void virtio_pci_release_dev(struct device *);
 
 int virtio_pci_legacy_probe(struct pci_dev *pci_dev,
                             const struct pci_device_id *id);
diff --git a/drivers/virtio/virtio_pci_legacy.c b/drivers/virtio/virtio_pci_legacy.c
index 6c76f0f5658c..a5486e65e04b 100644
--- a/drivers/virtio/virtio_pci_legacy.c
+++ b/drivers/virtio/virtio_pci_legacy.c
@@ -211,6 +211,17 @@ static const struct virtio_config_ops virtio_pci_config_ops = {
         .set_vq_affinity = vp_set_vq_affinity,
 };
 
+static void virtio_pci_release_dev(struct device *_d)
+{
+        struct virtio_device *vdev = dev_to_virtio(_d);
+        struct virtio_pci_device *vp_dev = to_vp_device(vdev);
+
+        /* As struct device is a kobject, it's not safe to
+         * free the memory (including the reference counter itself)
+         * until it's release callback. */
+        kfree(vp_dev);
+}
+
 /* the PCI probing function */
 int virtio_pci_legacy_probe(struct pci_dev *pci_dev,
                             const struct pci_device_id *id)
@@ -302,5 +313,4 @@ void virtio_pci_legacy_remove(struct pci_dev *pci_dev)
         pci_iounmap(pci_dev, vp_dev->ioaddr);
         pci_release_regions(pci_dev);
         pci_disable_device(pci_dev);
-        kfree(vp_dev);
 }