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

Pull virtio fixes from Michael Tsirkin:
 "This includes a couple of bugfixs for virtio.

  The virtio console patch is actually also in x86/tip targeting 4.9
  because it helps vmap stacks, but it also fixes IOMMU_PLATFORM which
  was added in 4.8, and it seems important not to ship that in a broken
  configuration"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  virtio_console: Stop doing DMA on the stack
  virtio: mark vring_dma_dev() static

2 files changed, 16 insertions, 9 deletions

diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index d2406fe25533..5da47e26a012 100644
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -165,6 +165,12 @@ struct ports_device {
          */
         struct virtqueue *c_ivq, *c_ovq;
 
+        /*
+         * A control packet buffer for guest->host requests, protected
+         * by c_ovq_lock.
+         */
+        struct virtio_console_control cpkt;
+
         /* Array of per-port IO virtqueues */
         struct virtqueue **in_vqs, **out_vqs;
 
@@ -560,28 +566,29 @@ static ssize_t __send_control_msg(struct ports_device *portdev, u32 port_id,
                                   unsigned int event, unsigned int value)
 {
         struct scatterlist sg[1];
-        struct virtio_console_control cpkt;
         struct virtqueue *vq;
         unsigned int len;
 
         if (!use_multiport(portdev))
                 return 0;
 
-        cpkt.id = cpu_to_virtio32(portdev->vdev, port_id);
-        cpkt.event = cpu_to_virtio16(portdev->vdev, event);
-        cpkt.value = cpu_to_virtio16(portdev->vdev, value);
-
         vq = portdev->c_ovq;
 
-        sg_init_one(sg, &cpkt, sizeof(cpkt));
-
         spin_lock(&portdev->c_ovq_lock);
-        if (virtqueue_add_outbuf(vq, sg, 1, &cpkt, GFP_ATOMIC) == 0) {
+
+        portdev->cpkt.id = cpu_to_virtio32(portdev->vdev, port_id);
+        portdev->cpkt.event = cpu_to_virtio16(portdev->vdev, event);
+        portdev->cpkt.value = cpu_to_virtio16(portdev->vdev, value);
+
+        sg_init_one(sg, &portdev->cpkt, sizeof(struct virtio_console_control));
+
+        if (virtqueue_add_outbuf(vq, sg, 1, &portdev->cpkt, GFP_ATOMIC) == 0) {
                 virtqueue_kick(vq);
                 while (!virtqueue_get_buf(vq, &len)
                         && !virtqueue_is_broken(vq))
                         cpu_relax();
         }
+
         spin_unlock(&portdev->c_ovq_lock);
         return 0;
 }
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index e383ecdaca59..ed9c9eeedfe5 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -167,7 +167,7 @@ static bool vring_use_dma_api(struct virtio_device *vdev)
  * making all of the arch DMA ops work on the vring device itself
  * is a mess.  For now, we use the parent device for DMA ops.
  */
-struct device *vring_dma_dev(const struct vring_virtqueue *vq)
+static struct device *vring_dma_dev(const struct vring_virtqueue *vq)
 {
         return vq->vq.vdev->dev.parent;
 }