diff options
Diffstat (limited to 'include/block/block.h')
| -rw-r--r-- | include/block/block.h | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/include/block/block.h b/include/block/block.h index 1f30a56fb0..9c76967104 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -18,6 +18,22 @@ typedef struct BlockDriverInfo { /* offset at which the VM state can be saved (0 if not possible) */ int64_t vm_state_offset; bool is_dirty; + /* + * True if unallocated blocks read back as zeroes. This is equivalent + * to the the LBPRZ flag in the SCSI logical block provisioning page. + */ + bool unallocated_blocks_are_zero; + /* + * True if the driver can optimize writing zeroes by unmapping + * sectors. This is equivalent to the BLKDISCARDZEROES ioctl in Linux + * with the difference that in qemu a discard is allowed to silently + * fail. Therefore we have to use bdrv_write_zeroes with the + * BDRV_REQ_MAY_UNMAP flag for an optimized zero write with unmapping. + * After this call the driver has to guarantee that the contents read + * back as zero. It is additionally required that the block device is + * opened with BDRV_O_UNMAP flag for this to work. + */ + bool can_write_zeroes_with_unmap; } BlockDriverInfo; typedef struct BlockFragInfo { |