FAILED: patch "[PATCH] virtio_console: don't tie bufs to a vq" failed to apply to 4.9-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

>From 2855b33514d290c51d52d94e25d3ef942cd4d578 Mon Sep 17 00:00:00 2001
From: "Michael S. Tsirkin" <mst@redhat.com>
Date: Fri, 20 Apr 2018 19:54:23 +0300
Subject: [PATCH] virtio_console: don't tie bufs to a vq

an allocated buffer doesn't need to be tied to a vq -
only vq->vdev is ever used. Pass the function the
just what it needs - the vdev.

Cc: stable@vger.kernel.org
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index 468f06134012..3e56f328b4cb 100644
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -422,7 +422,7 @@ static void reclaim_dma_bufs(void)
 	}
 }
 
-static struct port_buffer *alloc_buf(struct virtqueue *vq, size_t buf_size,
+static struct port_buffer *alloc_buf(struct virtio_device *vdev, size_t buf_size,
 				     int pages)
 {
 	struct port_buffer *buf;
@@ -445,16 +445,16 @@ static struct port_buffer *alloc_buf(struct virtqueue *vq, size_t buf_size,
 		return buf;
 	}
 
-	if (is_rproc_serial(vq->vdev)) {
+	if (is_rproc_serial(vdev)) {
 		/*
 		 * Allocate DMA memory from ancestor. When a virtio
 		 * device is created by remoteproc, the DMA memory is
 		 * associated with the grandparent device:
 		 * vdev => rproc => platform-dev.
 		 */
-		if (!vq->vdev->dev.parent || !vq->vdev->dev.parent->parent)
+		if (!vdev->dev.parent || !vdev->dev.parent->parent)
 			goto free_buf;
-		buf->dev = vq->vdev->dev.parent->parent;
+		buf->dev = vdev->dev.parent->parent;
 
 		/* Increase device refcnt to avoid freeing it */
 		get_device(buf->dev);
@@ -838,7 +838,7 @@ static ssize_t port_fops_write(struct file *filp, const char __user *ubuf,
 
 	count = min((size_t)(32 * 1024), count);
 
-	buf = alloc_buf(port->out_vq, count, 0);
+	buf = alloc_buf(port->portdev->vdev, count, 0);
 	if (!buf)
 		return -ENOMEM;
 
@@ -957,7 +957,7 @@ static ssize_t port_fops_splice_write(struct pipe_inode_info *pipe,
 	if (ret < 0)
 		goto error_out;
 
-	buf = alloc_buf(port->out_vq, 0, pipe->nrbufs);
+	buf = alloc_buf(port->portdev->vdev, 0, pipe->nrbufs);
 	if (!buf) {
 		ret = -ENOMEM;
 		goto error_out;
@@ -1374,7 +1374,7 @@ static unsigned int fill_queue(struct virtqueue *vq, spinlock_t *lock)
 
 	nr_added_bufs = 0;
 	do {
-		buf = alloc_buf(vq, PAGE_SIZE, 0);
+		buf = alloc_buf(vq->vdev, PAGE_SIZE, 0);
 		if (!buf)
 			break;