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authorChristoph Hellwig <hch@lst.de>2009-09-04 19:02:23 +0200
committerAnthony Liguori <aliguori@us.ibm.com>2009-09-11 10:19:46 -0500
commitaa659be3dc2aa86614bcf6960f9d4af2a4362156 (patch)
tree86739e8a381966394455528f26880d5de82a436b /hw/virtio-blk.h
parentb0484ae464dcd8ee7439c4257b2f40d6b0e007dd (diff)
virtio-blk: add volatile writecache feature
Add a new VIRTIO_BLK_F_WCACHE feature to virtio-blk to indicate that we have a volatile write cache that needs controlled flushing. Implement a VIRTIO_BLK_T_FLUSH operation to flush it. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Diffstat (limited to 'hw/virtio-blk.h')
-rw-r--r--hw/virtio-blk.h4
1 files changed, 4 insertions, 0 deletions
diff --git a/hw/virtio-blk.h b/hw/virtio-blk.h
index 1be4342706..23ad74caec 100644
--- a/hw/virtio-blk.h
+++ b/hw/virtio-blk.h
@@ -31,6 +31,7 @@
#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_WCACHE 9 /* write cache enabled */
#define VIRTIO_BLK_ID_LEN 256 /* length of identify u16 array */
#define VIRTIO_BLK_ID_SN 10 /* start of char * serial# */
@@ -55,6 +56,9 @@ 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
+/* Flush the volatile write cache */
+#define VIRTIO_BLK_T_FLUSH 4
+
/* Barrier before this op. */
#define VIRTIO_BLK_T_BARRIER 0x80000000