[Qemu-devel] [PATCH v1 0/8]: QMP: Thin provisioning support

[Luiz Capitulino]

Roughly speaking, thin provisioning is a feature where the VM is started with
a small storage and when a no space error is triggered, more space is allocated
and the VM is put to run again.

This series allows a management tool using QMP to implement thin provisioning
support. It does the following:

1. patches 1/8 and 2/8 extend the query-status command to contain a more
   complete and descriptive status

2. patches 3/8 to 6/8 add support to the block layer to track the status of
   the last executed I/O operation. This is supported by ide, virtio and scsi
   devices

3. The last two patches extend the "query-block" and "info block" commands
   to print the last I/O status field (this is per device)

Basically, all a management tool has to do to implement thin provisioning is
to wait for a BLOCK_IO_ERROR event (or the STOP event), check the VM is
stopped by issuing query-status and then find which device failed by using
query-block. Of course that the VM has to be configured to stop on errors.

A last important detail: Anthony has proposed how the query-status command
should be extended to support this[1]. However, I had to make the following
changes to his original proposal:

- Added states: debug, inmigrate, load-state-error and internal-error
- Dropped: singlestep

You'll find more details in the patches, thanks!

 [1] http://lists.nongnu.org/archive/html/qemu-devel/2011-06/msg00352.html

 block.c         |   37 ++++++++++++++++++++++++++++++++++++-
 block.h         |    7 +++++++
 block_int.h     |    2 ++
 gdbstub.c       |    4 ++++
 hw/ide/core.c   |    6 ++++++
 hw/scsi-disk.c  |    7 +++++++
 hw/virtio-blk.c |    4 ++++
 hw/watchdog.c   |    1 +
 kvm-all.c       |    1 +
 migration.c     |    3 +++
 monitor.c       |    8 +++++---
 qmp-commands.hx |   23 ++++++++++++++++++++++-
 sysemu.h        |   19 +++++++++++++++++++
 vl.c            |   37 +++++++++++++++++++++++++++++++++++++
 14 files changed, 154 insertions(+), 5 deletions(-)