2 files changed, 6 insertions, 1 deletions

diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index c4804f3465db..dd7ea203f940 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -260,6 +260,10 @@ static int virtblk_probe(struct virtio_device *vdev)
         if (virtio_has_feature(vdev, VIRTIO_BLK_F_BARRIER))
                 blk_queue_ordered(vblk->disk->queue, QUEUE_ORDERED_TAG, NULL);
 
+        /* If disk is read-only in the host, the guest should obey */
+        if (virtio_has_feature(vdev, VIRTIO_BLK_F_RO))
+                set_disk_ro(vblk->disk, 1);
+
         /* Host must always specify the capacity. */
         vdev->config->get(vdev, offsetof(struct virtio_blk_config, capacity),
                           &cap, sizeof(cap));
@@ -326,7 +330,7 @@ static struct virtio_device_id id_table[] = {
 
 static unsigned int features[] = {
         VIRTIO_BLK_F_BARRIER, VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX,
-        VIRTIO_BLK_F_GEOMETRY,
+        VIRTIO_BLK_F_GEOMETRY, VIRTIO_BLK_F_RO,
 };
 
 static struct virtio_driver virtio_blk = {
diff --git a/include/linux/virtio_blk.h b/include/linux/virtio_blk.h
index d4695a3356d0..b80919fad0ef 100644
--- a/include/linux/virtio_blk.h
+++ b/include/linux/virtio_blk.h
@@ -10,6 +10,7 @@
 #define VIRTIO_BLK_F_SIZE_MAX   1       /* Indicates maximum segment size */
 #define VIRTIO_BLK_F_SEG_MAX    2       /* Indicates maximum # of segments */
 #define VIRTIO_BLK_F_GEOMETRY   4       /* Legacy geometry available  */
+#define VIRTIO_BLK_F_RO         5       /* Disk is read-only */
 
 struct virtio_blk_config
 {