[PATCH 053/103] qemu: command: Introduce JSON variant of qemuBuildVirtioDevStr

[Peter Krempa]

Add a JSON variant of the generator of properties for virtio devices.
For convenience both the old and new are for now marked as unused, which
will be removed once the conversion is complete.

The formatted properties have following types according to QEMU.
'virtio-blk-pci' was used as an example:

  disable-legacy=<OnOffAuto> - on/off/auto (default: "auto")
  disable-modern=<bool>  -  (default: false)
  iommu_platform=<bool>  - on/off (default: false)
  ats=<bool>             - on/off (default: false)
  packed=<bool>          - on/off (default: false)

Note that <OnOffAuto> is an enum type without alternates in QMP so it
must be represented as a string in JSON.

Signed-off-by: Peter Krempa <pkrempa at redhat.com>
---
 src/qemu/qemu_command.c | 58 ++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 57 insertions(+), 1 deletion(-)

diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index 95395805e5..d27e8b2648 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -155,6 +155,16 @@ VIR_ENUM_IMPL(qemuAudioDriver,
 );


+static const char *
+qemuOnOffAuto(virTristateSwitch s)
+{
+    if (s == VIR_TRISTATE_SWITCH_ABSENT)
+        return NULL;
+
+    return virTristateSwitchTypeToString(s);
+}
+
+
 static int
 qemuBuildObjectCommandlineFromJSON(virCommand *cmd,
                                    virJSONValue *props,
@@ -980,6 +990,52 @@ qemuBuildVirtioDevGetConfig(virDomainDeviceDef *device,
 }


+/**
+ * qemuBuildVirtioDevProps
+ * @devtype: virDomainDeviceType of the device. Ex: VIR_DOMAIN_DEVICE_TYPE_RNG
+ * @devdata: *Def * of the device definition
+ * @qemuCaps: qemu capabilities
+ *
+ * Build the qemu virtio -device JSON properties name from the passed parameters.
+ */
+static G_GNUC_UNUSED virJSONValue *
+qemuBuildVirtioDevProps(virDomainDeviceType devtype,
+                        void *devdata,
+                        virQEMUCaps *qemuCaps)
+{
+    g_autoptr(virJSONValue) props = NULL;
+    virDomainDeviceDef device = { .type = devtype };
+    g_autofree char *model = NULL;
+    virTristateSwitch disableLegacy = VIR_TRISTATE_SWITCH_ABSENT;
+    virTristateSwitch disableModern = VIR_TRISTATE_SWITCH_ABSENT;
+    virDomainVirtioOptions *virtioOptions = NULL;
+
+    virDomainDeviceSetData(&device, devdata);
+
+    if (qemuBuildVirtioDevGetConfig(&device, qemuCaps, &model, &virtioOptions,
+                                    &disableLegacy, &disableModern) < 0)
+        return NULL;
+
+    if (virJSONValueObjectCreate(&props,
+                                 "s:driver", model,
+                                 "S:disable-legacy", qemuOnOffAuto(disableLegacy),
+                                 "T:disable-modern", disableModern,
+                                 NULL) < 0)
+        return NULL;
+
+    if (virtioOptions) {
+        if (virJSONValueObjectAdd(props,
+                                  "T:iommu_platform", virtioOptions->iommu,
+                                  "T:ats", virtioOptions->ats,
+                                  "T:packed", virtioOptions->packed,
+                                  NULL) < 0)
+            return NULL;
+    }
+
+    return g_steal_pointer(&props);
+}
+
+
 /**
  * qemuBuildVirtioDevStr
  * @buf: virBuffer * to append the built string
@@ -994,7 +1050,7 @@ qemuBuildVirtioDevGetConfig(virDomainDeviceDef *device,
  *
  * Returns: -1 on failure, 0 on success
  */
-static int
+static G_GNUC_UNUSED int
 qemuBuildVirtioDevStr(virBuffer *buf,
                       virQEMUCaps *qemuCaps,
                       virDomainDeviceType devtype,
-- 
2.31.1