With RHEL 6.2, virDomainBlockPull(dom, dev, bandwidth, 0) has a race
with non-zero bandwidth: there is a window between the block_stream
and block_job_set_speed monitor commands where an unlimited amount
of data was let through, defeating the point of a throttle.

This race was first identified in commit a9d3495e, and libvirt was
able to reduce the size of the window for that race.  In the meantime,
the qemu developers decided to fix things properly; per this message:
https://lists.gnu.org/archive/html/qemu-devel/2012-04/msg03793.html
the fix will be in qemu 1.1, and changes block-job-set-speed to use
a different parameter name, as well as adding a new optional parameter
to block-stream, which eliminates the race altogether.

Since our documentation already mentioned that we can refuse a non-zero
bandwidth for some hypervisors, I think the best solution is to do
just that for RHEL 6.2 qemu, so that the race is obvious to the user
(anyone using stock RHEL 6.2 binaries won't have this patch, and anyone
building their own libvirt with this patch for RHEL can also rebuild
qemu to get the modern semantics, so it is no real loss in behavior).

Meanwhile the code must be fixed to honor actual qemu 1.1 naming.
Rename the parameter to 'modern', since the naming difference now
covers more than just 'async' block-job-cancel.  And while at it,
fix an unchecked integer overflow.

* src/qemu/qemu_monitor.h (enum BLOCK_JOB_CMD): Drop unused value,
rename enum to match conventions.
* src/qemu/qemu_monitor.c (qemuMonitorBlockJob): Reflect enum rename.
* src/qemu_qemu_monitor_json.h (qemuMonitorJSONBlockJob): Likewise.
* src/qemu/qemu_monitor_json.c (qemuMonitorJSONBlockJob): Likewise,
and support difference between RHEL 6.2 and qemu 1.1 block pull.
* src/qemu/qemu_driver.c (qemuDomainBlockJobImpl): Reject
bandwidth during pull with too-old qemu.
* src/libvirt.c (virDomainBlockPull, virDomainBlockRebase):
Document this.

In my testing, I was able to provoke an odd block pull failure:

$ virsh blockpull dom vda --bandwidth 10000
error: Requested operation is not valid: No active operation on device: drive-virtio-disk0

merely by using gdb to artifically wait to do the block job set speed
until after the pull had already finished.  But in reality, that should
be a success, since the pull finished before we had a chance to set
speed.  Furthermore, using a double job lock is not only annoying, but
a bug in itself - if you do parallel virDomainBlockRebase, and hit
the race window just right, the first call grabs the VM job to start
a fast block job, then the second call grabs the VM job to start
a long-running job with unspecified speed, then the first call finally
regrabs the VM job and sets the speed, which ends up running the
second job under the speed from the first call.  By consolidating
things into a single job, we avoid opening that race, as well as reduce
the time between starting the job and changing the speed, for less
likelihood of the speed change happening after block job completion
in the first place.

* src/qemu/qemu_monitor.h (BLOCK_JOB_CMD): Add new mode.
* src/qemu/qemu_driver.c (qemuDomainBlockRebase): Move secondary
job call...
(qemuDomainBlockJobImpl): ...here, for fewer locks.
* src/qemu/qemu_monitor_json.c (qemuMonitorJSONBlockJob): Change
return value on new internal mode.

RHEL 6.2 was released with an early version of block jobs, which only
worked on the qed file format, where the commands were spelled with
underscore (contrary to QMP style), and where 'block_job_cancel' was
synchronous and did not trigger an event.

The upcoming qemu 1.1 release has fixed these short-comings [1][2]:
the commands now work on multiple file types, are spelled with dash,
and 'block-job-cancel' is asynchronous and emits an event upon conclusion.

[1]qemu commit 370521a1d6f5537ea7271c119f3fbb7b0fa57063
[2]https://lists.gnu.org/archive/html/qemu-devel/2012-04/msg01248.html

This patch recognizes the new spellings, and fixes virDomainBlockRebase
to give a graceful error when talking to a too-old qemu on a partial
rebase attempt.  Fixes for the new semantics will come later.  This
patch also removes a bogus ATTRIBUTE_NONNULL mistakenly added in
commit 10ec36e2.

* src/qemu/qemu_capabilities.h (QEMU_CAPS_BLOCKJOB_SYNC)
(QEMU_CAPS_BLOCKJOB_ASYNC): New bits.
* src/qemu/qemu_capabilities.c (qemuCaps): Name them.
* src/qemu/qemu_monitor_json.c (qemuMonitorJSONCheckCommands): Set
them.
(qemuMonitorJSONBlockJob): Manage both command names.
(qemuMonitorJSONDiskSnapshot): Minor formatting fix.
* src/qemu/qemu_monitor.h (qemuMonitorBlockJob): Alter signature.
* src/qemu/qemu_monitor_json.h (qemuMonitorJSONBlockJob): Likewise.
* src/qemu/qemu_monitor.c (qemuMonitorBlockJob): Pass through
capability bit.
* src/qemu/qemu_driver.c (qemuDomainBlockJobImpl): Update callers.

The oVirt developers have stated that the real reasons they want
to have qemu reuse existing volumes when creating a snapshot are:
1. the management framework is set up so that creation has to be
done from a central node for proper resource tracking, and having
libvirt and/or qemu create things violates the framework, and
2. qemu defaults to creating snapshots with an absolute path to
the backing file, but oVirt wants to manage a backing chain that
uses just relative names, to allow for easier migration of a chain
across storage locations.

When 0.9.10 added VIR_DOMAIN_SNAPSHOT_CREATE_REUSE_EXT (commit
4e9953a4), it only addressed point 1, but libvirt was still using
O_TRUNC which violates point 2.  Meanwhile, the new qemu
'transaction' monitor command includes a new optional mode argument
that will force qemu to reuse the metadata of the file it just
opened (with the burden on the caller to have valid metadata there
in the first place).  So, this tweaks the meaning of the flag to
cover both points as intended for use by oVirt.  It is not strictly
backward-compatible to 0.9.10 behavior, but it can be argued that
the O_TRUNC of 0.9.10 was a bug.

Note that this flag is all-or-nothing, and only selects between
'existing' and the default 'absolute-paths'.  A more flexible
approach that would allow per-disk selections, as well as adding
support for the 'no-backing-file' mode, would be possible by
extending the <domainsnapshot> xml to have a per-disk mode, but
until we have a management application expressing a need for that
additional complexity, it is not worth doing.

* src/libvirt.c (virDomainSnapshotCreateXML): Tweak documentation.
* src/qemu/qemu_monitor.h (qemuMonitorDiskSnapshot): Add
parameters.
* src/qemu/qemu_monitor_json.h (qemuMonitorJSONDiskSnapshot):
Likewise.
* src/qemu/qemu_monitor.c (qemuMonitorDiskSnapshot): Pass them
through.
* src/qemu/qemu_monitor_json.c (qemuMonitorJSONDiskSnapshot): Use
new monitor command arguments.
* src/qemu/qemu_driver.c (qemuDomainSnapshotCreateDiskActive)
(qemuDomainSnapshotCreateSingleDiskActive): Adjust callers.
(qemuDomainSnapshotDiskPrepare): Allow qed, modify rules on reuse.

QEmu 1.1 is adding a 'transaction' command to the JSON monitor.
Each element of a transaction corresponds to a top-level command,
with the additional guarantee that the transaction flushes all
pending I/O, then guarantees that all actions will be successful
as a group or that failure will roll back the state to what it
was before the monitor command.  The difference between a
top-level command:

{ "execute": "blockdev-snapshot-sync", "arguments":
  { "device": "virtio0", ... } }

and a transaction:

{ "execute": "transaction", "arguments":
  { "actions": [
    { "type": "blockdev-snapshot-sync", "data":
      { "device": "virtio0", ... } } ] } }

is just a couple of changed key names and nesting the shorter
command inside a JSON array to the longer command.  This patch
just adds the framework; the next patch will actually use a
transaction.

* src/qemu/qemu_monitor_json.c (qemuMonitorJSONMakeCommand): Move
guts...
(qemuMonitorJSONMakeCommandRaw): ...into new helper.  Add support
for array element.
(qemuMonitorJSONTransaction): New command.
(qemuMonitorJSONDiskSnapshot): Support use in a transaction.
* src/qemu/qemu_monitor_json.h (qemuMonitorJSONDiskSnapshot): Add
argument.
(qemuMonitorJSONTransaction): New declaration.
* src/qemu/qemu_monitor.h (qemuMonitorTransaction): Likewise.
(qemuMonitorDiskSnapshot): Add argument.
* src/qemu/qemu_monitor.c (qemuMonitorTransaction): New wrapper.
(qemuMonitorDiskSnapshot): Pass argument on.
* src/qemu/qemu_driver.c
(qemuDomainSnapshotCreateSingleDiskActive): Update caller.

This patch introduces a new event type for the QMP event
SUSPEND:

    VIR_DOMAIN_EVENT_ID_PMSUSPEND

The event doesn't take any data, but considering there might
be reason for wakeup in future, the callback definition is:

typedef void
(*virConnectDomainEventSuspendCallback)(virConnectPtr conn,
                                        virDomainPtr dom,
                                        int reason,
                                        void *opaque);

"reason" is unused currently, always passes "0".

This patch introduces a new event type for the QMP event
WAKEUP:

    VIR_DOMAIN_EVENT_ID_PMWAKEUP

The event doesn't take any data, but considering there might
be reason for wakeup in future, the callback definition is:

typedef void
(*virConnectDomainEventWakeupCallback)(virConnectPtr conn,
                                       virDomainPtr dom,
                                       int reason,
                                       void *opaque);

"reason" is unused currently, always passes "0".

This patch introduces a new event type for the QMP event
DEVICE_TRAY_MOVED, which occurs when the tray of a removable
disk is moved (i.e opened or closed):

    VIR_DOMAIN_EVENT_ID_TRAY_CHANGE

The event's data includes the device alias and the reason
for tray status' changing, which indicates why the tray
status was changed. Thus the callback definition for the event
is:

enum {
    VIR_DOMAIN_EVENT_TRAY_CHANGE_OPEN = 0,
    VIR_DOMAIN_EVENT_TRAY_CHANGE_CLOSE,

\#ifdef VIR_ENUM_SENTINELS
    VIR_DOMAIN_EVENT_TRAY_CHANGE_LAST
\#endif
} virDomainEventTrayChangeReason;

typedef void
(*virConnectDomainEventTrayChangeCallback)(virConnectPtr conn,
                                           virDomainPtr dom,
                                           const char *devAlias,
                                           int reason,
                                           void *opaque);

Using 'unsigned long' for memory values is risky on 32-bit platforms,
as a PAE guest can have more than 4GiB memory.  Our API is
(unfortunately) locked at 'unsigned long' and a scale of 1024, but
the rest of our system should consistently use 64-bit values,
especially since the previous patch centralized overflow checking.

* src/conf/domain_conf.h (_virDomainDef): Always use 64-bit values
for memory.  Change hugepage_backed to a bool.
* src/conf/domain_conf.c (virDomainDefParseXML)
(virDomainDefCheckABIStability, virDomainDefFormatInternal): Fix
clients.
* src/vmx/vmx.c (virVMXFormatConfig): Likewise.
* src/xenxs/xen_sxpr.c (xenParseSxpr, xenFormatSxpr): Likewise.
* src/xenxs/xen_xm.c (xenXMConfigGetULongLong): New function.
(xenXMConfigGetULong, xenXMConfigSetInt): Avoid truncation.
(xenParseXM, xenFormatXM): Fix clients.
* src/phyp/phyp_driver.c (phypBuildLpar): Likewise.
* src/openvz/openvz_driver.c (openvzDomainSetMemoryInternal):
Likewise.
* src/vbox/vbox_tmpl.c (vboxDomainDefineXML): Likewise.
* src/qemu/qemu_command.c (qemuBuildCommandLine): Likewise.
* src/qemu/qemu_process.c (qemuProcessStart): Likewise.
* src/qemu/qemu_monitor.h (qemuMonitorGetBalloonInfo): Likewise.
* src/qemu/qemu_monitor_text.h (qemuMonitorTextGetBalloonInfo):
Likewise.
* src/qemu/qemu_monitor_text.c (qemuMonitorTextGetBalloonInfo):
Likewise.
* src/qemu/qemu_monitor_json.h (qemuMonitorJSONGetBalloonInfo):
Likewise.
* src/qemu/qemu_monitor_json.c (qemuMonitorJSONGetBalloonInfo):
Likewise.
* src/qemu/qemu_driver.c (qemudDomainGetInfo)
(qemuDomainGetXMLDesc): Likewise.
* src/uml/uml_conf.c (umlBuildCommandLine): Likewise.

This actually wires up the new optional parameter to block_stream:
http://wiki.qemu.org/Features/LiveBlockMigration/ImageStreamingAPI

The error checking is still sparse, since libvirt must not use
qemu-img or header probing on a qcow2 file in use by qemu to
check if the backing file name is valid; so for now, libvirt is
relying on qemu to diagnose an incorrect backing name.  Fixing this
will require libvirt to track the entire backing file chain at the
time qemu is started and keeps it updated with snapshot and pull
operations.

* src/qemu/qemu_monitor_json.c (qemuMonitorJSONBlockJob): Add
parameter, and update callers.
* src/qemu/qemu_monitor_json.h (qemuMonitorJSONBlockJob): Update
signature.
* src/qemu/qemu_monitor.h (qemuMonitorBlockJob): Likewise.
* src/qemu/qemu_driver.c (qemuDomainBlockJobImpl): Update caller.
* src/qemu/qemu_monitor.c (qemuMonitorBlockJob): Likewise.

QMP commands don't need to be escaped since converting them to json
also escapes special characters. When a QMP command fails, however,
libvirt falls back to HMP commands. These fallback functions
(qemuMonitorText*) do their own escaping, and pass the result directly
to qemuMonitorHMPCommandWithFd. If the monitor is in json mode, these
pre-escaped commands will be escaped again when converted to json,
which can result in the wrong arguments being sent.

For example, a filename test\file would be sent in json as
test\\file.

This prevented attaching an image file with a " or \ in its name in
qemu 1.0.50, and also broke rbd attachment (which uses backslashes to
escape some internal arguments.)
Reported-by: NMasuko Tomoya <tomoya.masuko@gmail.com>
Signed-off-by: NJosh Durgin <josh.durgin@dreamhost.com>
Signed-off-by: NEric Blake <eblake@redhat.com>

using 'system-wakeup' monitor command. It is supported only in JSON,
as we are enabling it if possible. Moreover, this command is available
in qemu-1.1+ which definitely has JSON.

In the future (my next patch in fact) we may want to make
decisions depending on qemu having a monitor command or not.
Therefore, we want to set qemuCaps flag instead of querying
on the monitor each time we are about to make that decision.

QEMU always sends details about all available block devices as an answer
for "info block"/"query-block" command. On the other hand, our
qemuMonitorGetBlockInfo was made for a single block devices queries
only. Thus, when asking for multiple devices, we asked qemu multiple
times to always get the same answer from which different parts were
filtered. This patch makes qemuMonitorGetBlockInfo return a hash table
of all block devices, which may later be used for getting details about
specific devices.

In preparation for the patch to include Murmurhash3, which
introduces a virhashcode.h and virhashcode.c files, rename
the existing hash.h and hash.c to virhash.h and virhash.c
respectively.

Implement the block I/O throttle setting and getting support to qemu
driver.
Signed-off-by: NLei Li <lilei@linux.vnet.ibm.com>
Signed-off-by: NZhi Yong Wu <wuzhy@linux.vnet.ibm.com>
Signed-off-by: NEric Blake <eblake@redhat.com>

Implements functions for both HMP and QMP mode.

For HMP mode, qemu uses "M" as the units by default, so the passed "sized"
is divided by 1024.

For QMP mode, qemu uses "Bytes" as the units by default, the passed "sized"
is multiplied by 1024.

All of the monitor functions return -1 on failure, 0 on success, or -2 if
not supported.

The QEMU monitor command 'add_client' can be used to connect to
a VNC or SPICE graphics display. This allows for implementation
of the virDomainOpenGraphics API

* src/qemu/qemu_driver.c: Implement virDomainOpenGraphics
* src/qemu/qemu_monitor.c, src/qemu/qemu_monitor.h,
  src/qemu/qemu_monitor_json.c, src/qemu/qemu_monitor_json.h,
  src/qemu/qemu_monitor_text.c, src/qemu/qemu_monitor_text.h:
  Add binding for 'add_client' command

If the daemon is restarted so we reconnect to monitor, cdrom media
can be ejected. In that case we don't want to show it in domain xml,
or require it on migration destination.

To check for disk status use 'info block' monitor command.

Current qemu is able to give us detailed domain status (not just if it
is running or not) which we can translate into a status reason.

/usr/lib/stdlib.h in Mac OS X and probably also in BSD's
exports this symbol :(

This patch adds handlers for modification of guest's interface
link state. Both HMP and QMP commands are supported, but as the
link state functionality is from the beginning supported in QMP
the HMP code will probably never be used.

The mainly changes are:

1) Update qemuMonitorGetBlockStatsInfo and it's children (Text/JSON)
   functions to return the value of new latency fields.
2) Add new function qemuMonitorGetBlockStatsParamsNumber, which is
   to count how many parameters the underlying QEMU supports.
3) Update virDomainBlockStats in src/qemu/qemu_driver.c to be
   compatible with the changes by 1).

No one uses this yet, but it will be important once
virDomainSnapshotCreateXML learns a VIR_DOMAIN_SNAPSHOT_DISK_ONLY
flag, and the xml allows passing in the new file names.

* src/qemu/qemu_monitor.h (qemuMonitorDiskSnapshot): New prototype.
* src/qemu/qemu_monitor_text.h (qemuMonitorTextDiskSnapshot):
Likewise.
* src/qemu/qemu_monitor_json.h (qemuMonitorJSONDiskSnapshot):
Likewise.
* src/qemu/qemu_monitor.c (qemuMonitorDiskSnapshot): New
function.
* src/qemu/qemu_monitor_json.c (qemuMonitorJSONDiskSnapshot):
Likewise.

When an operation started by virDomainBlockPull completes (either with
success or with failure), raise an event to indicate the final status.
This API allow users to avoid polling on virDomainGetBlockJobInfo if
they would prefer to use an event mechanism.

* daemon/remote.c: Dispatch events to client
* include/libvirt/libvirt.h.in: Define event ID and callback signature
* src/conf/domain_event.c, src/conf/domain_event.h,
  src/libvirt_private.syms: Extend API to handle the new event
* src/qemu/qemu_driver.c: Connect to the QEMU monitor event
  for block_stream completion and emit a libvirt block pull event
* src/remote/remote_driver.c: Receive and dispatch events to application
* src/remote/remote_protocol.x: Wire protocol definition for the event
* src/remote_protocol-structs: structure definitions for protocol verification
* src/qemu/qemu_monitor.c, src/qemu/qemu_monitor.h,
  src/qemu/qemu_monitor_json.c: Watch for BLOCK_STREAM_COMPLETED event
  from QEMU monitor

The virDomainBlockPull* family of commands are enabled by the
following HMP/QMP commands: 'block_stream', 'block_job_cancel',
 'info block-jobs' / 'query-block-jobs', and 'block_job_set_speed'.

* src/qemu/qemu_driver.c src/qemu/qemu_monitor_text.[ch]: implement disk
  streaming by using the proper qemu monitor commands.
* src/qemu/qemu_monitor_json.[ch]: implement commands using the qmp monitor

qemu driver just accept xt_kbd codeset's keycode, so the lib virtkey
is used for translating keycodes from other codesets

When qemuMonitorCloseFileHandle is called in error path, we need to
preserve the original error since a possible further error when running
closefd monitor command is not very useful to users.

When attaching to an external QEMU process, it is neccessary
to check if the process is using KVM or not. This can be done
using a monitor command

* src/qemu/qemu_monitor.c, src/qemu/qemu_monitor.h,
  src/qemu/qemu_monitor_json.c, src/qemu/qemu_monitor_json.h,
  src/qemu/qemu_monitor_text.c, src/qemu/qemu_monitor_text.h: Add
  API for checking if KVM is enabled

This reverts commit 784ee08d.

This reverts commit 12cd77a0.

Conflicts:

	python/libvirt-override-virConnect.py
	python/libvirt-override.c
	src/remote/remote_protocol.x

For controlled shutdown we issue a 'system_powerdown' command
to the QEMU monitor. This triggers an ACPI event which (most)
guest OS wire up to a controlled shutdown. There is no equiv
ACPI event to trigger a controlled reboot. This patch attempts
to fake a reboot.

 - In qemuDomainObjPrivatePtr we have a bool fakeReboot
   flag.
 - The virDomainReboot method sets this flag and then
   triggers a normal 'system_powerdown'.
 - The QEMU process is started with '-no-shutdown'
   so that the guest CPUs pause when it powers off the
   guest
 - When we receive the 'POWEROFF' event from QEMU JSON
   monitor if fakeReboot is not set we invoke the
   qemuProcessKill command and shutdown continues
   normally
 - If fakeReboot was set, we spawn a background thread
   which issues 'system_reset' to perform a warm reboot
   of the guest hardware. Then it issues 'cont' to
   start the CPUs again

* src/qemu/qemu_command.c: Add -no-shutdown flag if
  we have JSON support
* src/qemu/qemu_domain.h: Add 'fakeReboot' flag to
  qemuDomainObjPrivate struct
* src/qemu/qemu_driver.c: Fake reboot using the
  system_powerdown command if JSON support is available
* src/qemu/qemu_monitor.c, src/qemu/qemu_monitor.h,
  src/qemu/qemu_monitor_json.c, src/qemu/qemu_monitor_json.h,
  src/qemu/qemu_monitor_text.c, src/qemu/qemu_monitor_text.h: Add
  binding for system_reset command
* src/qemu/qemu_process.c: Reset the guest & start CPUs if
  fakeReboot is set

When an operation started by virDomainBlockPullAll completes (either with
success or with failure), raise an event to indicate the final status.  This
allows an API user to avoid polling on virDomainBlockPullInfo if they would
prefer to use the event mechanism.

* daemon/remote.c: Dispatch events to client
* include/libvirt/libvirt.h.in: Define event ID and callback signature
* src/conf/domain_event.c, src/conf/domain_event.h,
  src/libvirt_private.syms: Extend API to handle the new event
* src/qemu/qemu_driver.c: Connect to the QEMU monitor event
  for block_stream completion and emit a libvirt block pull event
* src/remote/remote_driver.c: Receive and dispatch events to application
* src/remote/remote_protocol.x: Wire protocol definition for the event
* src/qemu/qemu_monitor.c, src/qemu/qemu_monitor.h,
  src/qemu/qemu_monitor_json.c: Watch for BLOCK_STREAM_COMPLETED event
  from QEMU monitor
Signed-off-by: NAdam Litke <agl@us.ibm.com>

The virDomainBlockPull* family of commands are enabled by the
'block_stream' and 'info block_stream' qemu monitor commands.

* src/qemu/qemu_driver.c src/qemu/qemu_monitor_text.[ch]: implement disk
  streaming by using the stream and info stream text monitor commands
* src/qemu/qemu_monitor_json.[ch]: implement commands using the qmp monitor
Signed-off-by: NAdam Litke <agl@us.ibm.com>
Acked-by: NDaniel P. Berrange <berrange@redhat.com>

Currently the QEMU monitor I/O handler code uses errno values
to report errors. This results in a sub-optimal error messages
on certain conditions, in particular when parsing JSON strings
malformed data simply results in 'EINVAL'.

This changes the code to use the standard libvirt error reporting
APIs. The virError is stored against the qemuMonitorPtr struct,
and when a monitor API is run, any existing stored error is copied
into that thread's error local

* src/qemu/qemu_monitor.c, src/qemu/qemu_monitor.h,
  src/qemu/qemu_monitor_json.c, src/qemu/qemu_monitor_text.c: Use
  virError APIs for all monitor I/O handling code

Currently whenever there is any failure with parsing the monitor,
this is treated in the same was as end-of-file (ie QEMU quit).
The domain is terminated, if not already dead.

With this change, failures in parsing the monitor stream do not
result in the death of QEMU. The guest continues running unchanged,
but all further use of the monitor will be disabled.

The VMM_FAILURE event will be emitted, and the mgmt application
can decide when to kill/restart the guest to re-gain control

* src/qemu/qemu_monitor.c, src/qemu/qemu_monitor.h: Run a
  different callback for monitor EOF vs error conditions.
* src/qemu/qemu_process.c: Emit VMM_FAILURE event when monitor
  fails

Use the graphics information from the QEMU migration cookie to
issue a 'client_migrate_info' monitor command to QEMU. This causes
the SPICE client to automatically reconnect to the target host
when migration completes

* src/qemu/qemu_migration.c: Set data for SPICE client relocation
  before starting migration on src
* src/qemu/qemu_monitor.c, src/qemu/qemu_monitor.h,
  src/qemu/qemu_monitor_json.c, src/qemu/qemu_monitor_json.h,
  src/qemu/qemu_monitor_text.c, src/qemu/qemu_monitor_text.h: Add
  new qemuMonitorGraphicsRelocate() command

A qemu domain can get paused when libvirtd is stopped (e.g., because of
I/O error) so we should check its current state when reconnecting to it.