[Qemu-devel] [PATCH 00/15] v3: virtio-serial-bus fixes, new abi for port discovery

[Amit Shah <amit.shah@redhat.com>]

Hello,

These patches rework the way ports are announced to the guests. A
control message is used to let the guest know a new port is
added. Initial port discovery and port hot-plug work via this way now.

This was done to have the host and guest port numbering in sync to
avoid surprises after several hotplug/unplug operations and
migrations.

The ability to assign a particular port number to ports is also added
so that management software can control the placement of ports.

Differences from v3:
- Add iov.[ch] and move memcpy_to_iovec from virtio-balloon.c and two
  fill_iov implementations from virtio-net.c and virtio-serial-bus.c
  there.

- New fix for not sending data to port if host connection is not open

- Rearranged patches: migration fixes first, some trivial ones next,
  followed by fixes and scatter/gather handling last.

- Plug a console port at id 0 only if an id is not supplied by user

- Let user know if a port or device failed to initialise on the guest

- Add QMP events to let mgmt know port or device addition in the guest
  failed.

Overall:
- Users can set the port id they wish to instantiate ports at by using
  the ,nr= parameter to 'virtserialport' and 'virtconsole' devices

- Migration fixes: refuse migration when:
  - number of active ports is different between the src and destination
  - max_nr_ports a device can support on the src is more

- If a qemu chardev connection to a port is closed on the dest while
  it was open on the src, inform the guest about this. (Also do the
  same for port closed on src but open on dest.)

- Use control messages for relaying new port information instead of
  config space (changes abi)

- Propagate error message from guest in instantiating a port or a
  device to the user as well as mgmt via QMP messages.

- Handle scatter/gather for control output and data output from the
  guest


Amit Shah (15):
  virtio-serial: save/load: Ensure target has enough ports
  virtio-serial: save/load: Ensure nr_ports on src and dest are same.
  virtio-serial: save/load: Ensure we have hot-plugged ports
    instantiated
  virtio-serial: save/load: Send target host connection status if
    different
  virtio-serial: Use control messages to notify guest of new ports
  virtio-serial: whitespace: match surrounding code
  virtio-serial: Remove redundant check for 0-sized write request
  virtio-serial: Update copyright year to 2010
  virtio-serial: Propagate errors in initialising ports / devices in
    guest
  virtio-serial: Add QMP events for failed port/device add
  virtio-serial: Send out guest data to ports only if port is opened
  iov: Introduce a new file for helpers around iovs, add iov_from_buf()
  iov: Add iov_to_buf and iov_size helpers
  virtio-serial: Handle scatter-gather buffers for control messages
  virtio-serial: Handle scatter/gather input from the guest

 Makefile.objs          |    1 +
 QMP/qmp-events.txt     |   48 +++++++++
 hw/iov.c               |   70 ++++++++++++
 hw/iov.h               |   19 ++++
 hw/virtio-balloon.c    |   35 +------
 hw/virtio-console.c    |    4 +-
 hw/virtio-net.c        |   20 +---
 hw/virtio-serial-bus.c |  277 +++++++++++++++++++++++++++++++++++++-----------
 hw/virtio-serial.h     |   19 ++--
 monitor.c              |    3 +
 monitor.h              |    1 +
 11 files changed, 380 insertions(+), 117 deletions(-)
 create mode 100644 hw/iov.c
 create mode 100644 hw/iov.h