8 files changed, 33 insertions, 18 deletions
diff --git a/include/linux/virtio.h b/include/linux/virtio.h
index 4fca4f5440ba..057a2e010758 100644
--- a/include/linux/virtio.h
+++ b/include/linux/virtio.h
@@ -34,7 +34,7 @@ struct virtqueue {
  *	out_num: the number of sg readable by other side
  *	in_num: the number of sg which are writable (after readable ones)
  *	data: the token identifying the buffer.
- *      Returns 0 or an error.
+ *      Returns remaining capacity of queue (sg segments) or a negative error.
  * @kick: update after add_buf
  *	vq: the struct virtqueue
  *	After one or more add_buf calls, invoke this to kick the other side.
diff --git a/include/linux/virtio_9p.h b/include/linux/virtio_9p.h
index b3c4a60ceeb3..ea7226a45acb 100644
--- a/include/linux/virtio_9p.h
+++ b/include/linux/virtio_9p.h
@@ -4,8 +4,6 @@
  * compatible drivers/servers. */
 #include <linux/virtio_config.h>
 
-/* The ID for virtio console */
-#define VIRTIO_ID_9P	9
 /* Maximum number of virtio channels per partition (1 for now) */
 #define MAX_9P_CHAN	1
 
diff --git a/include/linux/virtio_balloon.h b/include/linux/virtio_balloon.h
index 8726ff77763e..09d730085060 100644
--- a/include/linux/virtio_balloon.h
+++ b/include/linux/virtio_balloon.h
@@ -4,9 +4,6 @@
  * compatible drivers/servers. */
 #include <linux/virtio_config.h>
 
-/* The ID for virtio_balloon */
-#define VIRTIO_ID_BALLOON	5
-
 /* The feature bitmap for virtio balloon */
 #define VIRTIO_BALLOON_F_MUST_TELL_HOST	0 /* Tell before reclaiming pages */
 
diff --git a/include/linux/virtio_blk.h b/include/linux/virtio_blk.h
index 8dab9f2b8832..15cb666581d7 100644
--- a/include/linux/virtio_blk.h
+++ b/include/linux/virtio_blk.h
@@ -5,9 +5,6 @@
 #include <linux/types.h>
 #include <linux/virtio_config.h>
 
-/* The ID for virtio_block */
-#define VIRTIO_ID_BLOCK	2
-
 /* Feature bits */
 #define VIRTIO_BLK_F_BARRIER	0	/* Does host support barriers? */
 #define VIRTIO_BLK_F_SIZE_MAX	1	/* Indicates maximum segment size */
@@ -17,6 +14,7 @@
 #define VIRTIO_BLK_F_BLK_SIZE	6	/* Block size of disk is available*/
 #define VIRTIO_BLK_F_SCSI	7	/* Supports scsi command passthru */
 #define VIRTIO_BLK_F_IDENTIFY	8	/* ATA IDENTIFY supported */
+#define VIRTIO_BLK_F_FLUSH	9	/* Cache flush command support */
 
 #define VIRTIO_BLK_ID_BYTES	(sizeof(__u16[256]))	/* IDENTIFY DATA */
 
@@ -38,6 +36,17 @@ struct virtio_blk_config {
 	__u8 identify[VIRTIO_BLK_ID_BYTES];
 } __attribute__((packed));
 
+/*
+ * Command types
+ *
+ * Usage is a bit tricky as some bits are used as flags and some are not.
+ *
+ * Rules:
+ *   VIRTIO_BLK_T_OUT may be combined with VIRTIO_BLK_T_SCSI_CMD or
+ *   VIRTIO_BLK_T_BARRIER.  VIRTIO_BLK_T_FLUSH is a command of its own
+ *   and may not be combined with any of the other flags.
+ */
+
 /* These two define direction. */
 #define VIRTIO_BLK_T_IN		0
 #define VIRTIO_BLK_T_OUT	1
@@ -45,6 +54,9 @@ struct virtio_blk_config {
 /* This bit says it's a scsi command, not an actual read or write. */
 #define VIRTIO_BLK_T_SCSI_CMD	2
 
+/* Cache flush command */
+#define VIRTIO_BLK_T_FLUSH	4
+
 /* Barrier before this op. */
 #define VIRTIO_BLK_T_BARRIER	0x80000000
 
diff --git a/include/linux/virtio_console.h b/include/linux/virtio_console.h
index dc161115ae35..b5f519806014 100644
--- a/include/linux/virtio_console.h
+++ b/include/linux/virtio_console.h
@@ -5,9 +5,6 @@
 /* This header, excluding the #ifdef __KERNEL__ part, is BSD licensed so
  * anyone can use the definitions to implement compatible drivers/servers. */
 
-/* The ID for virtio console */
-#define VIRTIO_ID_CONSOLE	3
-
 /* Feature bits */
 #define VIRTIO_CONSOLE_F_SIZE	0	/* Does host provide console size? */
 
diff --git a/include/linux/virtio_ids.h b/include/linux/virtio_ids.h
new file mode 100644
index 000000000000..06660c0a78d7
--- /dev/null
+++ b/include/linux/virtio_ids.h
@@ -0,0 +1,17 @@
+#ifndef _LINUX_VIRTIO_IDS_H
+#define _LINUX_VIRTIO_IDS_H
+/*
+ * Virtio IDs
+ *
+ * This header is BSD licensed so anyone can use the definitions to implement
+ * compatible drivers/servers.
+ */
+
+#define VIRTIO_ID_NET		1 /* virtio net */
+#define VIRTIO_ID_BLOCK		2 /* virtio block */
+#define VIRTIO_ID_CONSOLE	3 /* virtio console */
+#define VIRTIO_ID_RNG		4 /* virtio ring */
+#define VIRTIO_ID_BALLOON	5 /* virtio balloon */
+#define VIRTIO_ID_9P		9 /* 9p virtio console */
+
+#endif /* _LINUX_VIRTIO_IDS_H */
diff --git a/include/linux/virtio_net.h b/include/linux/virtio_net.h
index d8dd539c9f48..1f41734bbb77 100644
--- a/include/linux/virtio_net.h
+++ b/include/linux/virtio_net.h
@@ -6,9 +6,6 @@
 #include <linux/virtio_config.h>
 #include <linux/if_ether.h>
 
-/* The ID for virtio_net */
-#define VIRTIO_ID_NET	1
-
 /* The feature bitmap for virtio net */
 #define VIRTIO_NET_F_CSUM	0	/* Host handles pkts w/ partial csum */
 #define VIRTIO_NET_F_GUEST_CSUM	1	/* Guest handles pkts w/ partial csum */
diff --git a/include/linux/virtio_rng.h b/include/linux/virtio_rng.h
index 1a85dab8a940..48121c3c434b 100644
--- a/include/linux/virtio_rng.h
+++ b/include/linux/virtio_rng.h
@@ -4,7 +4,4 @@
  * compatible drivers/servers. */
 #include <linux/virtio_config.h>
 
-/* The ID for virtio_rng */
-#define VIRTIO_ID_RNG	4
-
 #endif /* _LINUX_VIRTIO_RNG_H */