[libvirt] [PATCH v4 0/4] Implement migrate-getmaxdowntime command

[Scott Garfinkle]

Currently, the maximum tolerable downtime for a domain being migrated is
write-only. This patch implements a way to query that value nondestructively.

I've tried to incorporate the feedback from v3; however, I've left alone a
couple of places where the feedback would have diverged from parallelism with
the existing migrate-setdowntime help/info. Also, since the main use of this
new command is likely to be (as in virt-manager) in combination with 
migrate-setmaxdowntime, I don't think it's going to really help to add an
options to report this in some other unit other than milliseconds.

To-do: Ought to revisit setmaxdowntime to use the new preferred qemu interface.

Changes from [v3]:

* Incorporated suggestions, including adding an error message
* Added a patch to the news.xml file

[v1} https://www.redhat.com/archives/libvir-list/2017-July/msg00908.html
[v2} https://www.redhat.com/archives/libvir-list/2017-July/msg01010.html
[v3} https://www.redhat.com/archives/libvir-list/2017-July/msg01301.html

Scott Garfinkle (4)
    Add virDomainMigrateGetMaxDowntime public API
    qemu: Implement virDomainMigrateGetMaxDowntime
    virsh: Add support for virDomainMigrateGetMaxDowntime
    docs: document migrate-getmaxdowntime support

---
 docs/news.xml                    | 10 +++++++
 include/libvirt/libvirt-domain.h |  4 +++
 src/driver-hypervisor.h          |  6 +++++
 src/libvirt-domain.c             | 41 ++++++++++++++++++++++++++++
 src/libvirt_public.syms          |  4 +++
 src/qemu/qemu_driver.c           | 58 ++++++++++++++++++++++++++++++++++++++++
 src/qemu/qemu_monitor.h          |  3 +++
 src/qemu/qemu_monitor_json.c     |  4 +++
 src/remote/remote_driver.c       |  1 +
 src/remote/remote_protocol.x     | 16 ++++++++++-
 src/remote_protocol-structs      |  8 ++++++
 tools/virsh-domain.c             | 42 +++++++++++++++++++++++++++++
 tools/virsh.pod                  |  6 +++++
 13 files changed, 202 insertions(+), 1 deletion(-)