query-cpu-model-expansion is used to get a list of features for a given cpu
model name or to get the model and features of the host hardware/environment
as seen by Qemu/kvm.
Signed-off-by: Collin L. Walling <walling@linux.vnet.ibm.com>
Signed-off-by: Jason J. Herne <jjherne@linux.vnet.ibm.com>
Currently we build the JSON object for the "block_set_io_throttle"
command using the knowledge that a NULL for a support*Options boolean
would essentially ignore the rest of the arguments.
This may not work properly if some capability was backported, plus it just
looks rather ugly. So instead, build the "base" arguments and then if
the support*Option bool capability is set, add in the arguments on the fly.
Then append those arguments to the basic command and send to qemu.
QEMU 2.8.0 adds support for unavailable-features in
query-cpu-definitions reply. The unavailable-features array lists CPU
features which prevent a corresponding CPU model from being usable on
current host. It can only be used when all the unavailable features are
disabled. Empty array means the CPU model can be used without
modifications.
We can use unavailable-features for providing CPU model usability info
in domain capabilities XML:
<domainCapabilities>
...
<cpu>
<mode name='host-passthrough' supported='yes'/>
<mode name='host-model' supported='yes'>
<model fallback='allow'>Skylake-Client</model>
...
</mode>
<mode name='custom' supported='yes'>
<model usable='yes'>qemu64</model>
<model usable='yes'>qemu32</model>
<model usable='no'>phenom</model>
<model usable='yes'>pentium3</model>
<model usable='yes'>pentium2</model>
<model usable='yes'>pentium</model>
<model usable='yes'>n270</model>
<model usable='yes'>kvm64</model>
<model usable='yes'>kvm32</model>
<model usable='yes'>coreduo</model>
<model usable='yes'>core2duo</model>
<model usable='no'>athlon</model>
<model usable='yes'>Westmere</model>
<model usable='yes'>Skylake-Client</model>
...
</mode>
</cpu>
...
</domainCapabilities>
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
We have couple of functions that operate over NULL terminated
lits of strings. However, our naming sucks:
virStringJoin
virStringFreeList
virStringFreeListCount
virStringArrayHasString
virStringGetFirstWithPrefix
We can do better:
virStringListJoin
virStringListFree
virStringListFreeCount
virStringListHasString
virStringListGetFirstWithPrefix
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Whenever qemuMonitorJSONCheckError returns 0, the "return" object is
guaranteed to exist. Thus virJSONValueObjectGetObject will never fail to
get it. On the other hand, virJSONValueObjectGetArray may fail since the
"return" object may not be an array.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Add support for a duration/length for the bps/iops and friends.
Modify the API in order to add the "blkdeviotune." specific definitions
for the iotune throttling duration/length options
total_bytes_sec_max_length
write_bytes_sec_max_length
read_bytes_sec_max_length
total_iops_sec_max_length
write_iops_sec_max_length
read_iops_sec_max_length
This patch will also adjust the qemuMonitorJSONSetBlockIoThrottle error
procession so that rather than returning/displaying:
"error: internal error: Unexpected error"
Fetch the actual error message from qemu and display that
Extended the qemuMonitorCPUInfo with a halted flag. Extract the halted
flag for both text and JSON monitor.
Signed-off-by: Viktor Mihajlovski <mihajlov@linux.vnet.ibm.com>
Signed-off-by: Boris Fiuczynski <fiuczy@linux.vnet.ibm.com>
Since introduction of chardev hotplug the code was wrong for the UDP
case and basically created a TCP socket instead. Use proper objects and
type for UDP.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1377602
We're about to add more options, let's avoid having multiple if-then-else
which each try to set up the qemuMonitorJSONMakeCommand call with all the
parameters it knows about.
Instead, use the fact that when a NULL is found in the argument list that
processing of the remaining arguments stops and just have call.
Signed-off-by: John Ferlan <jferlan@redhat.com>
Reduce some cut-n-paste code by creating common helper. Make use of the
recently added virJSONValueObjectStealArray to grab the devices list as
part of the common code (we we can Free the reply) and return devices for
each of the callers to continue to parse.
NB: This also adds error checking to qemuMonitorJSONDiskNameLookup
Signed-off-by: John Ferlan <jferlan@redhat.com>
The list of supported CPU models in domain capabilities is stored in
virDomainCapsCPUModels. Let's use the same object for storing CPU models
in QEMU capabilities.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
If the incoming XML defined a path to a TLS X.509 certificate environment,
add the necessary 'tls-creds-x509' object to the VIR_DOMAIN_CHR_TYPE_TCP
character device.
Likewise, if the environment exists the hot unplug needs adjustment as
well. Note that all the return ret were changed to goto cleanup since
the cfg needs to be unref'd
Signed-off-by: John Ferlan <jferlan@redhat.com>
Add support for retrieving information regarding hotpluggable cpu units
supported by qemu. Data returned by the command carries information
needed to figure out the granularity of hotplug, the necessary cpu type
name and the topology information.
Note that qemu doesn't specify any particular order of the entries thus
it's necessary sort them by socket_id, core_id and thread_id to the
order libvirt expects.
To allow matching up the data returned by query-cpus to entries in the
query-hotpluggable-cpus reply for CPU hotplug it's necessary to extract
the QOM path as it's the only link between the two.
QEMU reports whether 'query-hotpluggable-cpus' is supported for a given
machine type. Extract and cache the information using the capability
cache.
When copying the capabilities for a new start of qemu, mask out the
presence of QEMU_CAPS_QUERY_HOTPLUGGABLE_CPUS if the machine type
doesn't support hotpluggable cpus.
Prepare to extract more data by returning an array of structs rather than
just an array of thread ids. Additionally report fatal errors separately
from qemu not being able to produce data.
The first argument should be const char ** instead of
char **, because this is a search function and as such it
doesn't, and shouldn't, alter the haystack in any way.
This change means we no longer have to cast arrays of
immutable strings to arrays of mutable strings; we still
have to do the opposite, though, but that's reasonable.
Move QEMU_DRIVE_HOST_PREFIX into the qemu_alias.c to dissuade future
callers from using it. Create qemuAliasDiskDriveSkipPrefix in order
to handle the current consumers that desire to check if an alias has
the drive- prefix and "get beyond it" in order to get the disk alias.
Since we already have a function that will generate the drivestr from
the alias, let's use it and remove the qemuDeviceDriveHostAlias.
Move the QEMU_DRIVE_HOST_PREFIX definition into qemu_alias.h
Also alter qemuAliasFromDisk to use the QEMU_DRIVE_HOST_PREFIX instead
of "drive-%s".
Rather than pass the disks[i]->info.alias to qemuMonitorSetDrivePassphrase
and then generate the "drive-%s" alias from that, let's use qemuAliasFromDisk
prior to the call to generate the drive alias and then pass that along
thus removing the need to generate the alias from the monitor code.
QEMU reports timestamp along with other memory statistics, but this information is not saved into domain statistics.
It could be useful to determine if the data reported is fresh or not.
Balloon statistics are not reported in hrf, so no modifications are made in qemu_monitor_text.c.
Signed-off-by: Derbyshev Dmitry <dderbyshev@virtuozzo.com>
'memtotal' in virtio drivers and qemu corresponds to 'available' in libvirt.
Because of that, 'stat-available-memory' is renamed into 'usable'.
Balloon statistics are not reported in hrf, so no modifications are made in qemu_monitor_text.c.
Signed-off-by: Derbyshev Dmitry <dderbyshev@virtuozzo.com>
Commit ce745914 introduced detection of actual video ram sizes to fix migration
if QEMU decide to modify the values provided by libvirt. This works perfectly
for domains with number of video devices up to two.
If there are more than two video devices in the guest all the secondary devices
in the XML will have the same memory values. This is because our current code
search for QOM device path only by the device type name and all the secondary
video devices has the same name "qxl".
This patch introduces a new search function that will try to search a QOM device
path using also device's alias if the alias is available. After that it will
fallback to the old recursive code if the alias search found no results.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1358728
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
We should not require any parameters to be present. After all we have
the *_set bools to express that some parameters were not set.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
qemuMonitorMigrationParams is a better name for a structure which
contains various migration parameters. While doing that, we should use
full names for individual parameters.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
https://bugzilla.redhat.com/show_bug.cgi?id=1298070
We have the code for attaching redirdevs for ages now.
Unfortunately, our monitor code that handles talking to the qemu
process was missing a little piece of code that actually enabled
the feature.
BTW: it really is called "type" on the monitor, even though it's
called "name" on the cmd line. Don't ask.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
CPUID instruction normally takes its parameter from EAX, but sometimes
ECX is used as an additional parameter. This patch prepares the x86 CPU
driver code for the new 'ecx_in' CPUID parameter.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
virCPUData, virCPUx86Feature, and virCPUx86Model all contained a pointer
to virCPUx86Data, which was not very nice since the real CPUID data were
accessible by yet another pointer from virCPUx86Data. Moreover, using
virCPUx86Data directly will make static definitions of internal CPU
features a bit easier.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
This patch splits qemuMonitorJSONGetCPUx86Data in three functions:
- qemuMonitorJSONCheckCPUx86 checks if QEMU supports reporting CPUID
features for a guest CPU
- qemuMonitorJSONParseCPUx86Features parses CPUID features from a JSON
array
- qemuMonitorJSONGetCPUx86Data gets the requested guest CPU property
from QOM and uses qemuMonitorJSONParseCPUx86Features to parse it
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
CPUID instruction normally takes its parameter from EAX, but sometimes
ECX is used as an additional parameter. Let's rename 'function' to
'eax_in' in preparation for adding 'ecx_in'.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Commit b4a5fd95 introduced vram64 attribute for QXL video device but
there were two issues. Only function
qemuMonitorJSONUpdateVideoVram64Size should update the vram64 attribute
and also the value is in MiB, not in B.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Extract whether a given drive has a tray and whether there is no image
inserted.
Negative logic for the image insertion is chosen so that the flag is set
only if we are certain of the fact.
Recent adjustments to the code produced a litany of coverity false
positives, but only because the "standard" procedure of setting a
variable to NULL after it was assigned to something else and keeping
the *Free/*FREE call in the cleanup path wasn't kept. So this patch
makes those adjustments (assign variable to NULL and remove the if
'ret < 0' condition to clean it up).
Signed-off-by: John Ferlan <jferlan@redhat.com>
In 7884d089d2 I've started to refactor qemu_monitor_json.c.
Thing is, it's current structure is nothing like the rest of our
code. The @ret variable is rewritten all the time, if()-s are
nested instead of using goto and so on.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
In majority of our functions we have this variable @ret that is
overwritten a lot. In other areas of the code we use 'goto
cleanup;' just so that this wouldn't happen. But here.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
In these functions I'm fixing here, we do call
qemuMonitorJSONCheckError() followed by another check if qemu
reply contains 'return' object. If it wouldn't, the former
CheckError() function would error out and the flow would not even
get to the latter.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Usually, the flow in this area of the code is as follows:
qemuMonitorJSONMakeCommand()
qemuMonitorJSONCommand()
qemuMonitorJSONCheckError()
parseReply()
But in this function, for some reasons, the last two steps were
swapped. This makes no sense.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
QEMU introduced the query-gic-capabilities QMP command
with commit 4468d4e0f383: use the command, if available,
to probe available GIC capabilities.
The information obtained is stored in a virQEMUCaps
instance, and will be later used to fill in a
virDomainCaps instance.
The event is emitted on ACPI OSPM Status Indication events.
ACPI standard documentation describes the method as:
This object is an optional control method that is invoked by OSPM to
indicate processing status to the platform. During device ejection,
device hot add, or other event processing, OSPM may need to perform
specific handshaking with the platform. OSPM may also need to indicate
to the platform its inability to complete a requested operation; for
example, when a user presses an ejection button for a device that is
currently in use or is otherwise currently incapable of being ejected.
In this case, the processing of the ACPI Eject Request notification by
OSPM fails. OSPM may indicate this failure to the platform through the
invocation of the _OST control method. As a result of the status
notification indicating ejection failure, the platform may take certain
action including reissuing the notification or perhaps turning on an
appropriate indicator light to signal the failure to the user.
qemu won't ever add those functions directly to QMP. They will be
replaced with 'blockdev-add' and 'blockdev-del' eventually. At this time
there's no need to keep the stubs around.
Additionally the drive_del stub in JSON contained dead code in the
attempt to report errors. (VIR_ERR_OPERATION_UNSUPPORTED was never
reported). Since the text impl does have the same message it is reported
anyways.
QEMU changed the error message to:
"Tray of device 'drive-sata0-0-1' is not open"
and they may change the error massage in the future.
This updates the code to not depend on the text from the error message
but only on error itself.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Migration enters "postcopy-active" state after QEMU switches to
post-copy and pauses guest CPUs. From libvirt's point of view this state
is similar to "completed" because we need to transfer guest execution to
the destination host.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
This attribute is used to extend secondary PCI bar and expose it to the
guest as 64bit memory. It works like this: attribute vram is there to
set size of secondary PCI bar and guest sees it as 32bit memory,
attribute vram64 can extend this secondary PCI bar. If both attributes
are used, guest sees two memory bars, both address the same memory, with
the difference that the 32bit bar can address only the first part of the
whole memory.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1260749
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Extract out the qemuParseCommandLine{String|Pid} into their own
separate module - taking with it all the various static functions.
Causes a ripple effect with a few other modules to include the
new qemu_parse_command.h.
Narrowed down the list of #include's in the split out module to
those that are necessary for build.
memory_dirty_rate corresponds to dirty-pages-rate in QEMU and
memory_iteration is what QEMU reports in dirty-sync-count.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
The structure actually contains migration statistics rather than just
the status as the name suggests. Renaming it as
qemuMonitorMigrationStats removes the confusion.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Commit 256496e1 introduced a detection if "is locked" in error replay
from qemu monitor. Commit c4073657 fixed a memory leak, but it was
pointed out by Peter, that this could be done cleaner without
stringifing the replay.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
The return value of virJSONValueToString() should be freed when
no longer needed. This is not the case after 256496e1.
==26902== 138 bytes in 2 blocks are definitely lost in loss record 1,051 of 1,239
==26902== at 0x4C29F80: malloc (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==26902== by 0xAA5F599: strdup (in /lib64/libc-2.21.so)
==26902== by 0x552BAD9: virStrdup (virstring.c:726)
==26902== by 0x54F60A7: virJSONValueToString (virjson.c:1790)
==26902== by 0x1DF6EBB9: qemuMonitorJSONEjectMedia (qemu_monitor_json.c:2225)
==26902== by 0x1DF57A4C: qemuMonitorEjectMedia (qemu_monitor.c:1985)
==26902== by 0x1DF1EF2D: qemuDomainChangeEjectableMedia (qemu_hotplug.c:199)
==26902== by 0x1DF90314: qemuDomainChangeDiskLive (qemu_driver.c:7985)
==26902== by 0x1DF90476: qemuDomainUpdateDeviceLive (qemu_driver.c:8030)
==26902== by 0x1DF91ED7: qemuDomainUpdateDeviceFlags (qemu_driver.c:8677)
==26902== by 0x561785F: virDomainUpdateDeviceFlags (libvirt-domain.c:8559)
==26902== by 0x134210: remoteDispatchDomainUpdateDeviceFlags (remote_dispatch.h:10966)
==26902== 106 bytes in 1 blocks are definitely lost in loss record 1,033 of 1,239
==26902== at 0x4C29F80: malloc (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==26902== by 0xAA5F599: strdup (in /lib64/libc-2.21.so)
==26902== by 0x552BAD9: virStrdup (virstring.c:726)
==26902== by 0x54F60A7: virJSONValueToString (virjson.c:1790)
==26902== by 0x1DF6EC0C: qemuMonitorJSONEjectMedia (qemu_monitor_json.c:2227)
==26902== by 0x1DF57A4C: qemuMonitorEjectMedia (qemu_monitor.c:1985)
==26902== by 0x1DF1EF2D: qemuDomainChangeEjectableMedia (qemu_hotplug.c:199)
==26902== by 0x1DF90314: qemuDomainChangeDiskLive (qemu_driver.c:7985)
==26902== by 0x1DF90476: qemuDomainUpdateDeviceLive (qemu_driver.c:8030)
==26902== by 0x1DF91ED7: qemuDomainUpdateDeviceFlags (qemu_driver.c:8677)
==26902== by 0x561785F: virDomainUpdateDeviceFlags (libvirt-domain.c:8559)
==26902== by 0x134210: remoteDispatchDomainUpdateDeviceFlags (remote_dispatch.h:10966)
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
The internal representation of a JSON array counts the items in
size_t. However, for some reason, when asking for the count it's
reported as int. Firstly, we need the function to return a signed
type as it's returning -1 on an error. But, not every system has
integer the same size as size_t. Therefore, lets return ssize_t.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Few parts of the code looked at the current progress of and assumed that
a two phase blockjob is in the _READY state as soon as the progress
reached 100% (info.cur == info.end). In current versions of qemu this
assumption is invalid and qemu exposes a new flag 'ready' in the
query-block-jobs output that is set to true if the job is actually
finished.
This patch adds internal data handling for reading the 'ready' flag and
acting appropriately as long as the flag is present.
While this still doesn't fix the virsh client problem with two phase
block jobs and the --pivot option, it at least improves the error
message:
$ virsh blockcommit --wait --verbose vm vda --base vda[1] --active --pivot
Block commit: [100 %]error: failed to pivot job for disk vda
error: internal error: unable to execute QEMU command 'block-job-complete': The active block job for device 'drive-virtio-disk0' cannot be completed
to
$ virsh blockcommit --wait --verbose VM vda --base vda[1] --active --pivot
Block commit: [100 %]error: failed to pivot job for disk vda
error: block copy still active: disk 'vda' not ready for pivot yet
Modify the eject monitor functions to parse the return code and detect,
whether the error contains "is locked" to report this type of failure to
upper layers.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Spice events have mostly similar information present in the event JSON
but they differ in the name of the element containing the port.
The JSON event also provides connection ID which might be useful in the
future.
This patch splits up the event parser code into two functions and the
SPICE reimplements the event parsing with correct names and drops the
VNC only stuff.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1236585
Instead of using qemuMonitorJSONDevGetBlockExtent (which I plan to
remove later) extract the data in place.
Additionally add a flag that will be set when the wr_highest_offset was
extracted correctly so that callers can act according to that.
The test case addition should help make sure that everything works.
This patch provides support for a new watchdog action "inject-nmi" which
allows to define an inject of a non-maskable interrupt into a guest.
Signed-off-by: Boris Fiuczynski <fiuczy@linux.vnet.ibm.com>
Reviewed-by: Daniel Hansel <daniel.hansel@linux.vnet.ibm.com>
Reviewed-by: Stefan Zimmermann <stzi@linux.vnet.ibm.com>
Reviewed-by: Tony Krowiak <akrowiak@linux.vnet.ibm.com>
Rather than grabbing an arbitrary JSON value and then checking
if it has the right type, we might as well request the correct
type to begin with.
* src/qemu/qemu_monitor_json.c (qemuMonitorJSONIOProcessEvent)
(qemuMonitorJSONCommandWithFd, qemuMonitorJSONHandleGraphics)
(qemuMonitorJSONGetStatus, qemuMonitorJSONExtractCPUInfo)
(qemuMonitorJSONGetVirtType, qemuMonitorJSONGetBalloonInfo)
(qemuMonitorJSONGetMemoryStats)
(qemuMonitorJSONDevGetBlockExtent)
(qemuMonitorJSONGetOneBlockStatsInfo)
(qemuMonitorJSONGetAllBlockStatsInfo)
(qemuMonitorJSONBlockStatsUpdateCapacityOne)
(qemuMonitorJSONBlockStatsUpdateCapacity)
(qemuMonitorJSONGetBlockExtent)
(qemuMonitorJSONGetMigrationStatusReply)
(qemuMonitorJSONGetDumpGuestMemoryCapability)
(qemuMonitorJSONAddFd, qemuMonitorJSONQueryRxFilterParse)
(qemuMonitorJSONExtractChardevInfo)
(qemuMonitorJSONDiskNameLookupOne)
(qemuMonitorJSONDiskNameLookup)
(qemuMonitorJSONGetAllBlockJobInfo)
(qemuMonitorJSONBlockIoThrottleInfo, qemuMonitorJSONGetVersion)
(qemuMonitorJSONGetMachines, qemuMonitorJSONGetCPUDefinitions)
(qemuMonitorJSONGetCommands, qemuMonitorJSONGetEvents)
(qemuMonitorJSONGetKVMState, qemuMonitorJSONGetObjectTypes)
(qemuMonitorJSONGetObjectListPaths)
(qemuMonitorJSONGetObjectProps, qemuMonitorJSONGetTargetArch)
(qemuMonitorJSONGetMigrationCapabilities)
(qemuMonitorJSONGetStringArray, qemuMonitorJSONAttachCharDev)
(qemuMonitorJSONGetCPUx86Data, qemuMonitorJSONGetIOThreads)
(qemuMonitorJSONGetMemoryDeviceInfo): Use shorter idioms.
Signed-off-by: Eric Blake <eblake@redhat.com>
QEMU_CAPS_SEAMLESS_MIGRATION capability says QEMU supports
SPICE_MIGRATE_COMPLETED event. Thus we can just drop all code which
polls query-spice and replace it with waiting for the event.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
"query-block-jobs" QMP command returns all running block jobs at once,
while qemuMonitorBlockJobInfo would only report one. This is not very
nice in case we need to check several block jobs. This patch refactors
the monitor code to always parse all block jobs and store them in a
hash.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
When traversing through the QOM tree, we're looking for
a link to a device, e.g.:
link<virtio-balloon-pci>
Introduce a helper that will format the link name at the start,
instead of doing it every time while recursing through the tree.
Rather than have a separate routine to parse the alias of an iothread
returned from qemu in order to get the iothread_id value, parse the alias
when returning and just return the iothread_id in qemuMonitorIOThreadInfoPtr
This set of patches removes the function, changes the "char *name" to
"unsigned int" and handles all the fallout.
qemuDomainBlockJobImpl become an unmaintainable mess over the years of
adding new stuff to it. This patch starts splitting up individual
functions from it until it can be killed entirely.
In bulk this will add lines of code rather than delete them but it will
be traded for maintainability.
My intention is to split qemuMonitorJSONBlockJob() into simpler separate
functions for every block job type. Since the error handling code is the
same for all block jobs, this patch extracts the code into a separate
function that will later be reused in more places.
With the new helper qemuMonitorJSONErrorIsClass we can save a few
function calls as we can extract the error object once.
Split out the function that checks the actual error class string into a
separate helper as it will be useful later and refactor
qemuMonitorJSONHasError to return bool type and remove few useless
checks.
Basically virJSONValueObjectHasKey are useless here since the next call
to virJSONValueObjectGet is checking the return value again (which can't
fail at that point). By removing the first check we save a function
call.
