2 files changed, 16 insertions, 4 deletions

diff --git a/include/uapi/linux/virtio_blk.h b/include/uapi/linux/virtio_blk.h
index 3c53eec4ae22..19c66fcbab8a 100644
--- a/include/uapi/linux/virtio_blk.h
+++ b/include/uapi/linux/virtio_blk.h
@@ -60,7 +60,7 @@ struct virtio_blk_config {
         __u32 size_max;
         /* The maximum number of segments (if VIRTIO_BLK_F_SEG_MAX) */
         __u32 seg_max;
-        /* geometry the device (if VIRTIO_BLK_F_GEOMETRY) */
+        /* geometry of the device (if VIRTIO_BLK_F_GEOMETRY) */
         struct virtio_blk_geometry {
                 __u16 cylinders;
                 __u8 heads;
@@ -119,7 +119,11 @@ struct virtio_blk_config {
 #define VIRTIO_BLK_T_BARRIER    0x80000000
 #endif /* !VIRTIO_BLK_NO_LEGACY */
 
-/* This is the first element of the read scatter-gather list. */
+/*
+ * This comes first in the read scatter-gather list.
+ * For legacy virtio, if VIRTIO_F_ANY_LAYOUT is not negotiated,
+ * this is the first element of the read scatter-gather list.
+ */
 struct virtio_blk_outhdr {
         /* VIRTIO_BLK_T* */
         __virtio32 type;
diff --git a/include/uapi/linux/virtio_scsi.h b/include/uapi/linux/virtio_scsi.h
index 42b9370771b0..cc18ef8825c0 100644
--- a/include/uapi/linux/virtio_scsi.h
+++ b/include/uapi/linux/virtio_scsi.h
@@ -29,8 +29,16 @@
 
 #include <linux/virtio_types.h>
 
-#define VIRTIO_SCSI_CDB_SIZE   32
-#define VIRTIO_SCSI_SENSE_SIZE 96
+/* Default values of the CDB and sense data size configuration fields */
+#define VIRTIO_SCSI_CDB_DEFAULT_SIZE   32
+#define VIRTIO_SCSI_SENSE_DEFAULT_SIZE 96
+
+#ifndef VIRTIO_SCSI_CDB_SIZE
+#define VIRTIO_SCSI_CDB_SIZE VIRTIO_SCSI_CDB_DEFAULT_SIZE
+#endif
+#ifndef VIRTIO_SCSI_SENSE_SIZE
+#define VIRTIO_SCSI_SENSE_SIZE VIRTIO_SCSI_SENSE_DEFAULT_SIZE
+#endif
 
 /* SCSI command request, followed by data-out */
 struct virtio_scsi_cmd_req {