Hi,

Patch v11 has been modified, thanks to Klaus for the code review.

v10->v11:
- Before executing the pr operation, check whether it is supported.
  If it is not supported, return NVME_INVALID_OPCODE directly.

v9->v10:
- When the driver does not support the pr operation, the error
  code returned by nvme changes to Invalid Command Opcode.

v8->v9:
- Fix double-free and remove persistent reservation operations at nvme_is_write().

v7->v8:
- Fix num_keys may be less than 0 at scsi_pr_read_keys_complete().
- Fix buf memory leak at iscsi driver.

v6->v7:
- Add buferlen size check at SCSI layer.
- Add pr_cap calculation in bdrv_merge_limits() function at block layer,
  so the ugly bs->file->bs->bl.pr_cap in scsi and nvme layers was
  changed to bs->bl.pr_cap.
- Fix memory leak at iscsi driver, and some other spelling errors.

v5->v6:
- Add relevant comments in the io layer.

v4->v5:
- Fixed a memory leak bug at hw/nvme/ctrl.c.

v3->v4:
- At the nvme layer, the two patches of enabling the ONCS
  function and enabling rescap are combined into one.
- At the nvme layer, add helper functions for pr capacity
  conversion between the block layer and the nvme layer.

v2->v3:
In v2 Persist Through Power Loss(PTPL) is enable default.
In v3 PTPL is supported, which is passed as a parameter.

v1->v2:
- Add sg_persist --report-capabilities for SCSI protocol and enable
  oncs and rescap for NVMe protocol.
- Add persistent reservation capabilities constants and helper functions for
  SCSI and NVMe protocol.
- Add comments for necessary APIs.

v1:
- Add seven APIs about persistent reservation command for block layer.
  These APIs including reading keys, reading reservations, registering,
  reserving, releasing, clearing and preempting.
- Add the necessary pr-related operation APIs for both the
  SCSI protocol and NVMe protocol at the device layer.
- Add scsi driver at the driver layer to verify the functions

Changqi Lu (10):
  block: add persistent reservation in/out api
  block/raw: add persistent reservation in/out driver
  scsi/constant: add persistent reservation in/out protocol constants
  scsi/util: add helper functions for persistent reservation types
    conversion
  hw/scsi: add persistent reservation in/out api for scsi device
  block/nvme: add reservation command protocol constants
  hw/nvme: add helper functions for converting reservation types
  hw/nvme: enable ONCS and rescap function
  hw/nvme: add reservation protocal command
  block/iscsi: add persistent reservation in/out driver

 block/block-backend.c             | 403 +++++++++++++++++++++++++++
 block/io.c                        | 164 +++++++++++
 block/iscsi.c                     | 433 ++++++++++++++++++++++++++++++
 block/raw-format.c                |  56 ++++
 hw/nvme/ctrl.c                    | 349 +++++++++++++++++++++++-
 hw/nvme/ns.c                      |  11 +
 hw/nvme/nvme.h                    |  93 +++++++
 hw/scsi/scsi-disk.c               | 368 +++++++++++++++++++++++++
 include/block/block-common.h      |  40 +++
 include/block/block-io.h          |  20 ++
 include/block/block_int-common.h  |  84 ++++++
 include/block/nvme.h              | 107 +++++++-
 include/scsi/constants.h          |  52 ++++
 include/scsi/utils.h              |   8 +
 include/sysemu/block-backend-io.h |  24 ++
 scsi/utils.c                      |  81 ++++++
 16 files changed, 2291 insertions(+), 2 deletions(-)

-- 
2.20.1