[libvirt] [PATCH RFC 00/22] Move process code to qemu_process

[Chris Venteicher]

Make process code usable outside qemu_capabilities by moving code
from qemu_capabilities to qemu_process and exposing public functions.

The process code is used to activate a non domain QEMU process for QMP
message exchanges.

This patch set modifies capabilities to use the new public functions.

--

The process code is being decoupled from qemu_capabilities now to
support hypervisor baseline and comparison using QMP commands.

This patch set was originally submitted as part of the baseline patch set:
  [libvirt] [PATCH v4 00/37] BaselineHypervisorCPU using QEMU QMP exchanges
  https://www.redhat.com/archives/libvir-list/2018-November/msg00091.html

The baseline and comparison requirements are described here:
https://bugzilla.redhat.com/show_bug.cgi?id=1511999
https://bugzilla.redhat.com/show_bug.cgi?id=1511996


I am extracting and resubmitting just the process changes as a stand
alone series to try to make review easier.

The patch set shows capabilities using the public functions.
To see baseline using the public functions...
Look at the "qemu_driver:" patches at the end of
https://www.redhat.com/archives/libvir-list/2018-November/msg00091.html

Also,
The "qemu_driver: Support feature expansion via QEMU when baselining cpu"
patch might be of particular interest because the same QEMU process is
used for both baseline and expansion using QMP commands.

--

Many patches were used to isolate code moves and name changes from other
actual implementation changes.

The patches reuse the pattern of public qemuProcess{Start,Stop} functions
and internal static qemuProcess{Init,Launch,ConnectMonitor} functions
but adds a "Qmp" suffix to make them unique.

A number of patches are about re-partitioning the code into static
functions for initialization, process launch and connection monitor
stuff.  This matches the established pattern in qemu_process and seemed
to make sense to do.

For concurrency...
A thread safe library function creates a unique directory under libDir for each QEMU
process (for QMP messaging) to decouple processes in terms of sockets and
file system footprint.

Every patch should compile independently if applied in sequence.


Chris Venteicher (22):
  qemu_process: Move process code from qemu_capabilities to qemu_process
  qemu_process: Use qemuProcess prefix
  qemu_process: Limit qemuProcessNew to const input strings
  qemu_process: Refer to proc not cmd in process code
  qemu_process: Use consistent name for stop process function
  qemu_capabilities: Stop QEMU process before freeing
  qemu_process: Use qemuProcess struct for a single process
  qemu_process: Persist stderr in qemuProcess struct
  qemu_capabilities: Detect caps probe failure by checking monitor ptr
  qemu_process: Introduce qemuProcessStartQmp
  qemu_process: Collect monitor code in single function
  qemu_process: Store libDir in qemuProcess struct
  qemu_process: Setup paths within qemuProcessInitQmp
  qemu_process: Stop retaining Qemu Monitor config in qemuProcess
  qemu_process: Don't open monitor if process failed
  qemu_process: Cleanup qemuProcess alloc function
  qemu_process: Cleanup qemuProcessStopQmp function
  qemu_process: Catch process free before process stop
  qemu_monitor: Make monitor callbacks optional
  qemu_process: Enter QMP command mode when starting QEMU Process
  qemu_process: Use unique directories for QMP processes
  qemu_process: Stop locking QMP process monitor immediately

 src/qemu/qemu_capabilities.c | 300 +++++------------------------
 src/qemu/qemu_monitor.c      |   4 +-
 src/qemu/qemu_process.c      | 356 +++++++++++++++++++++++++++++++++++
 src/qemu/qemu_process.h      |  37 ++++
 tests/qemucapabilitiestest.c |   7 +
 5 files changed, 444 insertions(+), 260 deletions(-)

-- 
2.17.1