[Qemu-devel] [PATCH v4 0/6] virtio-blk: add DISCARD and WRITE_ZEROES features

[Stefano Garzarella <sgarzare@redhat.com>]

This series adds the support of DISCARD and WRITE_ZEROES commands
and extends the virtio-blk-test to test WRITE_ZEROES command when
the feature is enabled.

v4:
- fixed error with mingw compiler in patch 4
  gcc and clang want %lu, but mingw wants %llu for BDRV_REQUEST_MAX_SECTORS.
  Since is less than INT_MAX, I casted it to integer and I used %d in the
  format string of error_setg. (mingw now is happy)

v3:
- rebased on master (I removed Based-on tag since the new virtio headers from
  linux v5.0-rc1 are merged)
- added patch 2 to add host_features field (as in virtio-net) [Michael]
- fixed patch 3 (previously 2/5) using the new host_features field
- fixed patch 4 (previously 3/5) following the Stefan's comments:
                - fixed name of functions and fields
                - used vdev and s pointers
                - removed "wz-may-unmap" property
                - split "dwz-max-sectors" in two properties

v2:
- added patch 1 to use virtio_blk_handle_rw_error() with discard operation
- added patch 2 to make those new features machine-type dependent (thanks David)
- fixed patch 3 (previously patch 1/2) adding more checks, block_acct_start()
                for WRITE_ZEROES requests, and configurable parameters to
                initialize the limits (max_sectors, wzeroes_may_unmap).
                (thanks Stefan)
                I moved in a new function the code to handle a single segment,
                in order to simplify the support of multiple segments in the
                future.
- added patch 4 to change the assert on data_size following the discussion with
                Thomas, Changpeng, Michael, and Stefan (thanks all)
- fixed patch 5 (previously patch 2/2) using local dwz_hdr variable instead of
                dynamic allocation (thanks Thomas)

Thanks,
Stefano

Stefano Garzarella (6):
  virtio-blk: add acct_failed param to virtio_blk_handle_rw_error()
  virtio-blk: add host_features field in VirtIOBlock
  virtio-blk: add "discard" and "write-zeroes" properties
  virtio-blk: add DISCARD and WRITE_ZEROES features
  tests/virtio-blk: change assert on data_size in virtio_blk_request()
  tests/virtio-blk: add test for WRITE_ZEROES command

 hw/block/virtio-blk.c          | 214 +++++++++++++++++++++++++++++++--
 hw/core/machine.c              |   2 +
 include/hw/virtio/virtio-blk.h |   5 +-
 tests/virtio-blk-test.c        |  75 +++++++++++-
 4 files changed, 282 insertions(+), 14 deletions(-)

-- 
2.20.1