31567 Commits

Author SHA1 Message Date
Stefan Berger
488711a6ed qemu: Move code to add encryption options for swtpm_setup into function
Move the code that adds encryption options for the swtpm_setup command
line into its own function.

Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
2021-11-02 10:34:39 +01:00
Peter Krempa
626b53ba9b virQEMUQAPISchemaTraverseEnum: Allow query of enume type features
QEMU-6.2 added feature flags for enum types. Add support for querying
them into our QMP schema query language.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2021-11-01 17:37:15 +01:00
Peter Krempa
2827c411c2 virQEMUQAPISchemaTraverseEnum: Use the modern 'members' array
Starting from QEMU-6.2 enum members are reported as an array of objects
under new name "values" so that extra data can be reported for each
member.

Modify the code so that we prefer 'members' and skip 'values' completely
if we've used 'members'.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2021-11-01 17:37:15 +01:00
Peter Krempa
ce07b86008 virQEMUQAPISchemaTraverseEnum: Move helper variables into loop
Move them closer to where they are actually used.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2021-11-01 17:37:15 +01:00
Peter Krempa
4c8f4123c8 qemuMonitorJSONSave[Physical|Virtual]Memory: Reformat function headers
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2021-11-01 16:14:53 +01:00
Peter Krempa
e09b427ae9 qemuMonitorEjectMedia: Remove stale comment
The QMP implementation didn't use any new approach. The command itself
is now only used with legacy qemu versions.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2021-11-01 16:14:53 +01:00
Peter Krempa
ac9f3a4444 qemu: monitor: Remove unused qemuMonitorSetCPU
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2021-11-01 16:14:53 +01:00
Peter Krempa
deaeb480c5 qemuDomainHotplugAddVcpu: Remove legacy hotplug branch
Report an error if the new hotplug is not supported and remove the
alternate code paths.

The modern cpu-hotplug code was introduced in qemu-2.7. We keep the
capability so that proper errors are reported in case a platform doesn't
support hotplug.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2021-11-01 16:14:53 +01:00
Peter Krempa
a1ef0b129a qemuMonitorJSONBlockInfoAdd: Refactor hash table addition
Open code virHashAddEntry so that the error code path can be avoided.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2021-11-01 16:14:53 +01:00
Peter Krempa
04a248eb01 qemuMonitorJSONQueryBlock: Reformat function header
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2021-11-01 16:14:53 +01:00
Michal Privoznik
2996a94dd0 lib: Don't check for virCapabilitiesAddGuestDomain() retval
The virCapabilitiesAddGuestDomain() function can't fail. It
aborts on OOM. Therefore, there's no need to check for its
return value.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2021-11-01 16:08:26 +01:00
Michal Privoznik
c18d9e23fa lib: Don't check for virCapabilitiesAddGuest() retval
The virCapabilitiesAddGuest() function can't fail. It aborts on
OOM. Therefore, there's no need to check for its return value.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2021-11-01 16:05:52 +01:00
Michal Privoznik
42cc2f9396 ch_driver: Drop needless fwd declaration
In ch_driver.c there are two forward declarations that are not
needed. Drop them.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2021-11-01 16:04:11 +01:00
zhangjl02
f3ac931d36 virnetdevopenvswitch: unify calculation of ovs and tc
For other interface type, values in tc rules are calculated by
multiply by 8*1000 instead of 8*1024.

Signed-off-by: zhangjl02 <zhangjl02@inspur.com>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
2021-11-01 15:56:47 +01:00
Stefan Berger
0b4705a4aa qemu: tpm: Enable creation of certs for TPM 1.2 in non-privileged mode
When 'swtpm_setup --print-capabilities' shows the 'tpm12-not-need-root'
flag, then it is possible to create certificates for the TPM 1.2 also
in non-privileged mode since swtpm_setup doesn't need tcsd anymore.
Check for this flag and create the certificates if this flag is found.

Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
2021-11-01 15:51:05 +01:00
zhenwei pi
b2757b697e qemu: support kvm-pv-ipi off
QEMU version 3.1 introduced PV_SEND_IPI CPUID feature bit under
commit 7f710c32bb8 (target-i386: adds PV_SEND_IPI CPUID feature bit).

This patch adds a new KVM feature 'pv-ipi' to disable this feature
(enabled by default). Newer CPU platform (Ex, AMD Zen2) supports
hardware accelation for IPI in guest, to use this feature to get
better performance in some scenarios. Detailed about the discussion:
  https://lkml.org/lkml/2021/10/20/423

To disable kvm-pv-ipi and have libvirt add "-cpu host,kvm-pv-ipi=off"
to the QEMU command line, the following XML code needs to be added to the
guest's domain description:

  <features>
    <kvm>
      <pv-ipi state='off'/>
    </kvm>
  </features>

Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
2021-11-01 15:44:26 +01:00
Kristina Hanicova
d7547dbcf3 qemu_agent: remove unused code
This section of code was left unused ever since it was introduced
ten years ago. I think we can safely remove it.

Signed-off-by: Kristina Hanicova <khanicov@redhat.com>
Signed-off-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2021-11-01 15:33:59 +01:00
Tim Wiederhake
ed87c62c2b Fix some typos
Signed-off-by: Tim Wiederhake <twiederh@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2021-10-27 18:38:50 +02:00
Michal Privoznik
efc1ccc75b qemu: Set "qemu-event" thread identity
It may happen that qemuProcessStop() is called from "qemu-event"
thread. But this thread doesn't have any virIdentity set
(virIdentity being thread local) and therefore it may be unable
to open connection to secondary drivers. It is unable to do so
in split daemon scenario, because in there opening a connection
is coupled with copying current thread identity onto the
connection. Code-wise, virIdentityGetCurrent() returns NULL which
in turn makes virGetConnectGeneric() fail. This problem does not
occur in monolithic daemon scenario, because no identity copying
is done there.

Long story short, inability to open secondary driver connection
can lead to unwanted results. Therefore, do what
qemuProcessReconnectHelper() does - set the new thread identity
to be the one of the caller.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=2013573
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
2021-10-27 17:11:39 +02:00
Michal Privoznik
0c8f1aeddf virthreadpool: Allow setting identity for workers
In some cases the worker func running inside the pool may rely on
virIdentity. While worker func could check for identity and set
one it is not optimal - it may not have access to the identity of
the thread creating the pool and thus would have to call
virIdentityGetSystem(). Allow passing identity when creating the
pool.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
2021-10-27 17:11:29 +02:00
Michal Privoznik
030e80042e qemuProcessHandleMemoryDeviceSizeChange: Use qemuProcessEventSubmit()
This is a typical example of what can go wrong when sending out
an old patch. Back in January, when I was writing
qemuProcessHandleMemoryDeviceSizeChange() events were sent to the
worker pool thread using virThreadPoolSendJob(). Then, in July a
helper was introduced (qemuProcessEventSubmit()) but since my
code was not committed and I did not pay attention my code wasn't
updated. Later, when I merged my code it uses the old approach.

BTW: this also fixes a possible double free which I completely
missed when writing the code ~10 months ago.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2021-10-26 10:43:55 +02:00
Michal Privoznik
14c60c3ae7 qemu_monitor: Make domainMemoryDeviceSizeChange cb return void
Nobody's interested in the return value of any of
struct _qemuMonitorCallbacks callbacks. They are all void, but
domainMemoryDeviceSizeChange. Change it to void.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2021-10-26 10:43:55 +02:00
Jiri Denemark
5198c2542a storage_file: Compute QCOW2 cluster size as ULL
While the QCOW2 cluster size is represented in only 4 bits in the QCOW2
header and thus 1 << cluster_size cannot overflow int,
qcow2GetClusterSize is supposed to return unsigned long long so we can
just compute the result as ULL rather than computing it as int and
promoting to unsigned long long.

Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
2021-10-26 10:04:43 +02:00
Jiri Denemark
d5b3c62e81 node_device: Fix memory leak in udevProcessMediatedDevice
One of the paths returned -1 directly without going through the cleanup
section.

Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Reviewed-by: Laine Stump <laine@redhat.com>
2021-10-26 10:03:52 +02:00
Jiri Denemark
b564ce40aa util: Drop pointless NUL_TERMINATE macro
It's only used once and open coding it is at least as clear as using the
macro.

Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2021-10-26 10:03:36 +02:00
Ani Sinha
54cf221b55 qemu: remove unused function return value
qemuBuildPMPCIRootHotplugCommandLine() returns 0 unconditionally. There is no
failure scenario at present. So clean up the code by removing integer return
from the function and also remove the failure check conditional from the
function call.
Also fix indentation for the above function call while at it.

Signed-off-by: Ani Sinha <ani@anisinha.ca>
Reviewed-by: Laine Stump <laine@redhat.com>
2021-10-25 23:43:31 -04:00
Ani Sinha
d89fd6d93d qemu: Fix hotplug error message format to conform to spec
Error messages must conform to spec as specified here:
https://www.libvirt.org/coding-style.html#error-message-format

This change makes some error messages conform to the spec above.

Fixes: 8eadf82fb5 ("conf: introduce option to enable/disable pci hotplug on pci-root controller")

Signed-off-by: Ani Sinha <ani@anisinha.ca>
Reviewed-by: Laine Stump <laine@redhat.com>
2021-10-25 23:42:01 -04:00
Laine Stump
97475487f8 Revert "qemu: capablities: detect acpi-pci-hotplug-with-bridge-support"
This reverts commit 58ba0f6a3d7342fba29edbbf2bb9cb5497c870e5.

Conflict:
  * src/qemu/qemu_capabilities.[ch]

    Because other new cap flags had been added since the original
    commit, reformatting was necessary to follow the "groups of
    five" pattern.

  * tests.qemucapabilitiesdata/caps_6.2.0.x86_64.xml

    This file was added after the original commit that we
    are reverting, so had to be manually edited to remove
    the two capabilities.

Signed-off-by: Laine Stump <laine@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Ani Sinha <ani@anisinha.ca>
2021-10-25 23:18:41 -04:00
Laine Stump
dba9893831 Revert "conf: introduce support for acpi-bridge-hotplug feature"
This reverts commit 7300ccc9b3eddb38306868534e7fc2d505a0a13c.

Signed-off-by: Laine Stump <laine@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Ani Sinha <ani@anisinha.ca>
2021-10-25 23:18:41 -04:00
Laine Stump
26e8eda46e Revert "qemu: command: add support for acpi-bridge-hotplug feature"
This reverts commit bef0f0d8be6baa1d9359be208b53d6b8a37ddc95.

Conflicts:
 tests/qemuxml2argvdata/q35-acpi-hotplug-bridge-disable.args

  * this file had been renamed from its original, then renamed back,
    which understandably confused git. It's being completely removed
    here anyway, so the contents don't matter.

 tests/qemuxml2argvtest.c

  * change in context around removed chunk

Signed-off-by: Laine Stump <laine@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Ani Sinha <ani@anisinha.ca>
2021-10-25 23:18:41 -04:00
Laine Stump
4f4fffc073 Revert "qemuValidateDomainDefPCIFeature: un-break error messages"
This reverts commit 7d074c56830c5d435f87667299cc102650dbbb4f.

Signed-off-by: Laine Stump <laine@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Ani Sinha <ani@anisinha.ca>
2021-10-25 23:18:41 -04:00
Laine Stump
4aa75c3e4b Revert "qemuValidateDomainDefPCIFeature: Fix validation logic"
This reverts commit bdc3e8f47be108fa552b72a6d913528869e61097.

Signed-off-by: Laine Stump <laine@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Ani Sinha <ani@anisinha.ca>
2021-10-25 23:18:40 -04:00
Laine Stump
d65eb5dd8d Revert "qemu: capabilities: Remove QEMU_CAPS_PIIX4_ACPI_HOTPLUG_BRIDGE"
This reverts commit 618e8665db2e4c1a8e9a227045b99b48f6110c06.

This is the first in a series of 10 commits that revert (in reverse
order) the changes to add the <acpi-hotplug-bridge state='on|off'/>
switch to libvirt domain XML, which unfortunately needs to be removed
due to QEMU developers discovering a flaw with the design of the QEMU
commandline switch used to implement the libvirt switch that will
likely result in a new and different method of selecting hotplug
modes. Because the libvirt switch has not been in any official
releases of libvirt, we are still able to remove it completely, rather
than deprecating it.

The original commits began with commit
58ba0f6a3d7342fba29edbbf2bb9cb5497c870e5. The other original commit
IDs are documented in each revert commit.

Signed-off-by: Laine Stump <laine@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Ani Sinha <ani@anisinha.ca>
2021-10-25 23:18:40 -04:00
Or Ozeri
060f344c80 conf: add luks2 encryption format
This commit extends libvirt XML configuration to support luks2 encryption format.
This means that <encryption format="luks2" engine="librbd"> becomes valid.
Currently librbd is the only engine that supports this new format.

Signed-off-by: Or Ozeri <oro@il.ibm.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2021-10-25 14:06:15 +02:00
Or Ozeri
59090adf63 qemu: add librbd encryption engine
rbd encryption is new in qemu 6.1.0.
This commit adds a new encryption engine property which
allows the user to use this new encryption engine.

Signed-off-by: Or Ozeri <oro@il.ibm.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2021-10-25 14:06:15 +02:00
Or Ozeri
ab1d46d612 conf: add encryption engine property
This commit extends libvirt XML configuration to support a custom encryption engine.
This means that <encryption format="luks" engine="qemu">  becomes valid.
The only engine for now is qemu. However, a new engine (librbd) will be added in an upcoming commit.
If no engine is specified, qemu will be used (assuming qemu driver is used).

Signed-off-by: Or Ozeri <oro@il.ibm.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2021-10-25 14:06:15 +02:00
Or Ozeri
0398be5da6 qemu: capablities: Detect presence of 'rbd-encryption' as QEMU_CAPS_RBD_ENCRYPTION
rbd encryption is new in qemu 6.1.0.
This commit adds capability probing for it.

Signed-off-by: Or Ozeri <oro@il.ibm.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2021-10-25 14:06:15 +02:00
Or Ozeri
9696427ad6 qemu: add disk post parse to qemublocktest
The post parse callback is part of the real (non-test) processing flow.
This commit adds it (for disks) to the qemublocktest flow as well.
Specifically, this will be needed for tests that use luks encryption,
so that the default encryption engine (which is added in an upcoming commit)
will be overridden by qemu.

Signed-off-by: Or Ozeri <oro@il.ibm.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2021-10-25 14:06:15 +02:00
Michal Privoznik
91e206427f qemu_monitor_json: Drop pointless error labels
After previous cleanups, some 'error' labels were rendered
needless - they contain nothing more than a return statement.
Well, those labels can be dropped and 'goto error' can be
replaced with return statement directly.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Tim Wiederhake <twiederh@redhat.com>
2021-10-25 13:42:57 +02:00
Michal Privoznik
3361cc2f3c qemu_monitor_json: Drop pointless cleanup labels
After previous cleanups, some 'cleanup' labels were rendered
needless - they contain nothing more than a return statement.
Well, those labels can be dropped and 'goto cleanup' can be
replaced with return statement directly.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Tim Wiederhake <twiederh@redhat.com>
2021-10-25 13:42:51 +02:00
Michal Privoznik
a8ab1dd4cb qemu_monitor_json: Use g_autofree
Let's replace VIR_FREE() calls with g_autofree. Not all calls can
be replaced though - the legitimate ones are kept (e.g. those
which free array, or which free a struct for which we don't have
g_autoptr() yet, and so on).

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Tim Wiederhake <twiederh@redhat.com>
2021-10-25 13:42:47 +02:00
Michal Privoznik
551f91b4cb qemu_monitor_json: Use g_autoptr() for virJSONValue
A lot of explicit free calls can be saved when virJSONValue
variables are declared with g_autoptr(). There's one caveat:
there was a slight deviation from our usual pattern such that
@cmd variable was not initialized to NULL but as the very first
step it was assigned a value using qemuMonitorJSONMakeCommand().
While this works in theory it upset my GCC-11.2 (but only when
building with -O2). So I had to initialize the variable in such
case too.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Tim Wiederhake <twiederh@redhat.com>
2021-10-25 13:42:43 +02:00
Michal Privoznik
40bbcb47cc qemuMonitorJSONExtractPRManagerInfo: Declare @entry inside the loop
The reason why @entry variable in qemuMonitorJSONExtractPRManagerInfo()
was declared at the top most level was that the variable is used under
the cleanup label.  However, if declared using g_autofree then the
variable can be declared inside the loop it is used in.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Tim Wiederhake <twiederh@redhat.com>
2021-10-25 13:42:39 +02:00
Michal Privoznik
3e27dbc029 qemu_monitor_json: Use g_autoptr() for qemuMonitorCPUModelInfo
There's one place (specifically qemuMonitorJSONParseCPUModel())
where we can avoid explicit free call for qemuMonitorCPUModelInfo
struct.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Tim Wiederhake <twiederh@redhat.com>
2021-10-25 13:42:36 +02:00
Michal Privoznik
c63955ab0f qemu_monitor_json: Use g_autoptr() for virCPUData
We have g_autoptr() for virCPUData struct defined already. Let's
use it in qemu_monitor_json.c and drop explicit free calls.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Tim Wiederhake <twiederh@redhat.com>
2021-10-25 13:42:32 +02:00
Michal Privoznik
3dfc47c1fd qemu_monitor: Declare and use g_autoptr for qemuMonitorEventPanicInfo
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Tim Wiederhake <twiederh@redhat.com>
2021-10-25 13:42:27 +02:00
Michal Privoznik
4b1b14170a qemuMonitorJSONQueryRxFilterParse: Set *filter only on success
The qemuMonitorJSONQueryRxFilterParse() function is called to
parse the output of 'query-rx-filter' and store results into
passed virNetDevRxFilter structure. However, it is doing so in a
bit clumsy way - the return pointer is set in all cases (i.e.
even in case of error) and thus the cleanup label is more
complicated than it needs to be. With a help of g_autoptr() and
g_steal_pointer() the return pointer can be set only in case of
success - which is what callers expect anyway.

The same applies to qemuMonitorJSONQueryRxFilter().

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Tim Wiederhake <twiederh@redhat.com>
2021-10-25 13:42:22 +02:00
Michal Privoznik
4e8bb57859 qemuMonitorJSONGetMigrationStats: Don't clear @stats on failure
In the qemuMonitorJSONGetMigrationStats() there's a code under
cleanup label that's clearing returned @stats if the function
returns with an error. However, transitively there's just one
caller - qemuMigrationAnyFetchStats() - and it doesn't care for
this behaviour. Drop the code to simplify the cleanup label.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Tim Wiederhake <twiederh@redhat.com>
2021-10-25 13:42:19 +02:00
Michal Privoznik
a70ae22cfd qemuMonitorJSONHumanCommand: Require @reply_str
All callers of qemuMonitorJSONHumanCommand() pass a non-NULL pointer
as @reply_str therefore there's no need to check whether it is NULL.
NB, the sister function (qemuMonitorJSONArbitraryCommand()) doesn't
check for NULL either.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Tim Wiederhake <twiederh@redhat.com>
2021-10-25 13:42:14 +02:00
Michal Privoznik
2d7257d528 qemu_monitor_json: Don't transfer ownership to @msg
In qemuMonitorJSONCommandWithFd() given command (represented by
virJSONValue struct) is translated to string (represented by
virBuffer). The ownership of the string is then transferred to
the message which is then sent. The downside of this approach is
we have to have an explicit call to free the string from the
message. But if the message just "borrowed" the string (which it
can safely do because it is just reading from the string) then
automatic free of the buffer takes care of freeing the string.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Tim Wiederhake <twiederh@redhat.com>
2021-10-25 13:42:00 +02:00