2 files changed, 27 insertions, 4 deletions

diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index 78be6b8c89e0..84e064ffee52 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -157,10 +157,25 @@ static int virtblk_ioctl(struct inode *inode, struct file *filp,
 /* We provide getgeo only to please some old bootloader/partitioning tools */
 static int virtblk_getgeo(struct block_device *bd, struct hd_geometry *geo)
 {
-        /* some standard values, similar to sd */
-        geo->heads = 1 << 6;
-        geo->sectors = 1 << 5;
-        geo->cylinders = get_capacity(bd->bd_disk) >> 11;
+        struct virtio_blk *vblk = bd->bd_disk->private_data;
+        struct virtio_blk_geometry vgeo;
+        int err;
+
+        /* see if the host passed in geometry config */
+        err = virtio_config_val(vblk->vdev, VIRTIO_BLK_F_GEOMETRY,
+                                offsetof(struct virtio_blk_config, geometry),
+                                &vgeo);
+
+        if (!err) {
+                geo->heads = vgeo.heads;
+                geo->sectors = vgeo.sectors;
+                geo->cylinders = vgeo.cylinders;
+        } else {
+                /* some standard values, similar to sd */
+                geo->heads = 1 << 6;
+                geo->sectors = 1 << 5;
+                geo->cylinders = get_capacity(bd->bd_disk) >> 11;
+        }
         return 0;
 }
 
@@ -310,6 +325,7 @@ 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,
 };
 
 static struct virtio_driver virtio_blk = {
diff --git a/include/linux/virtio_blk.h b/include/linux/virtio_blk.h
index c75a9e82b924..d4695a3356d0 100644
--- a/include/linux/virtio_blk.h
+++ b/include/linux/virtio_blk.h
@@ -9,6 +9,7 @@
 #define VIRTIO_BLK_F_BARRIER    0       /* Does host support barriers? */
 #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  */
 
 struct virtio_blk_config
 {
@@ -18,6 +19,12 @@ struct virtio_blk_config
         __le32 size_max;
         /* The maximum number of segments (if VIRTIO_BLK_F_SEG_MAX) */
         __le32 seg_max;
+        /* geometry the device (if VIRTIO_BLK_F_GEOMETRY) */
+        struct virtio_blk_geometry {
+                __le16 cylinders;
+                __u8 heads;
+                __u8 sectors;
+        } geometry;
 } __attribute__((packed));
 
 /* These two define direction. */