[Qemu-devel] [PATCH V4 1/7] block: add block conversion api

[Devin Nakamura]

add functions to block driver interface to support inplace image conversion

Signed-off-by: Devin Nakamura <address@hidden>
---
 block.h     |    3 ++
 block_int.h |   82 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 85 insertions(+), 0 deletions(-)

diff --git a/block.h b/block.h
index a3bfaaf..4bdd82e 100644
--- a/block.h
+++ b/block.h
@@ -35,6 +35,7 @@ typedef struct QEMUSnapshotInfo {
 #define BDRV_O_NATIVE_AIO  0x0080 /* use native AIO instead of the thread pool 
*/
 #define BDRV_O_NO_BACKING  0x0100 /* don't open the backing file */
 #define BDRV_O_NO_FLUSH    0x0200 /* disable flushing on this disk */
+#define BDRV_O_CONVERSION  0x0400 /* open as conversion target */
 
 #define BDRV_O_CACHE_MASK  (BDRV_O_NOCACHE | BDRV_O_CACHE_WB | BDRV_O_NO_FLUSH)
 
@@ -254,6 +255,8 @@ int64_t bdrv_get_dirty_count(BlockDriverState *bs);
 void bdrv_set_in_use(BlockDriverState *bs, int in_use);
 int bdrv_in_use(BlockDriverState *bs);
 
+typedef struct BlockConversionOptions BlockConversionOptions;
+
 typedef enum {
     BLKDBG_L1_UPDATE,
 
diff --git a/block_int.h b/block_int.h
index f6d02b3..66660f4 100644
--- a/block_int.h
+++ b/block_int.h
@@ -42,6 +42,9 @@
 #define BLOCK_OPT_PREALLOC      "preallocation"
 #define BLOCK_OPT_SUBFMT        "subformat"
 
+#define BLOCK_CRYPT_NONE    0
+#define BLOCK_CRYPT_AES     1
+
 typedef struct AIOPool {
     void (*cancel)(BlockDriverAIOCB *acb);
     int aiocb_size;
@@ -145,6 +148,79 @@ struct BlockDriver {
      */
     int (*bdrv_has_zero_init)(BlockDriverState *bs);
 
+    /* In-place image conversion */
+
+    /**
+     * Opens an image conversion target.
+     *
+     * @param bs          Basic Initialization done by
+     *                    bdrv_open_conversion_target() Still need to set 
format
+     *                    specific data.
+     * @param usr_options Creation options.
+     * @param drv_options Conversion Options
+     * @return            Returns non-zero on failure.
+     */
+    int (*bdrv_open_conversion_target)(BlockDriverState *bs,
+        BlockConversionOptions *drv_options, QEMUOptionParameter *usr_options,
+        bool force);
+
+    /**
+     * Gets a mapping from an offset in the image to an offset within a file
+     *
+     * All offsets are in bytes.
+     *
+     * @param guest_offset          The starting offset of the mapping
+     * @param host_offset[out]      The starting file offset of the mapping.
+     *                              A value of -1 is invalid and means the
+     *                              cluster is unallocated (contiguous_bytes is
+     *                              still valid)
+     * @param contiguous_bytes[out] The number of bytes for which this mapping
+     *                              is contiguous. If 0, there are no more
+     *                              mapppings in the image
+     * @return                      Returns 0 on error;
+     */
+
+    int (*bdrv_get_mapping)(BlockDriverState *bs, uint64_t guest_offset,
+        uint64_t *host_offset, uint64_t *contiguous_bytes);
+
+    /**
+     * Sets a mapping in the image file.
+     *
+     * @param bs               Usually opened with bdrv_open_conversion_target
+     * @param guest_offset     The starting guest offset of the mapping
+     *                         (in bytes).
+     * @param host_offset      The starting image offset of the mapping
+     *                         (in bytes).
+     * @param contiguous_bytes The number of bytes for which this mapping 
exists
+     * @return                 Returns non-zero on error. Will return -EINVAL 
if
+     *                         guest_offset, host_offset, or contiguous_bytes
+     *                         not cluster aligned
+     */
+    int (*bdrv_map)(BlockDriverState *bs, uint64_t guest_offset,
+        uint64_t host_offset, uint64_t contiguous_bytes);
+
+    /**
+     * Copies out the header of a conversion target
+     *
+     * Saves the current header for the image in a temporary file and 
overwrites
+     * it with the header for the new format (at the moment the header is
+     * assumed to be 1 sector)
+     * @param bs        Usualy opened with bdrv_open_conversion_target()
+     * @param filename  The name of the file to copy the header into
+     * @return          Returns non-zero on failure
+     */
+    int (*bdrv_copy_header) (BlockDriverState *bs, char* filename);
+
+    /**
+     * Asks the block driver what options should be used to create a conversion
+     * target.
+     *
+     * @param options[out] Block conversion options
+     */
+    int (*bdrv_get_conversion_options)(BlockDriverState *bs,
+         BlockConversionOptions *options);
+
+
     QLIST_ENTRY(BlockDriver) list;
 };
 
@@ -269,4 +345,10 @@ static inline unsigned int 
get_physical_block_exp(BlockConf *conf)
     DEFINE_PROP_UINT32("discard_granularity", _state, \
                        _conf.discard_granularity, 0)
 
+struct BlockConversionOptions {
+    int encryption_type;
+    uint64_t image_size;
+    uint64_t cluster_size;
+    int nb_snapshots;
+};
 #endif /* BLOCK_INT_H */
-- 
1.7.6.rc1