10:12 a.m.
We will soon need to be able to return a NULL pointer
without the caller considering that an error: to make
it possible, change the return type to int and use
an out parameter for the string instead.
Add some documentation for the function as well.
---
src/qemu/qemu_command.c | 53 ++++++++++++++++++++++++++++++++++++-------------
src/qemu/qemu_command.h | 9 +++++----
src/qemu/qemu_hotplug.c | 5 ++++-
3 files changed, 48 insertions(+), 19 deletions(-)
diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index 41eecfd..73767fb 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -2520,10 +2520,31 @@ qemuBuildUSBControllerDevStr(virDomainControllerDefPtr def,
}
-char *
+/**
+ * qemuBuildControllerDevStr:
+ * @domainDef: domain definition
+ * @def: controller definition
+ * @qemuCaps: QEMU binary capabilities
+ * @devstr: device string
+ * @nusbcontroller: number of USB controllers
+ *
+ * Turn @def into a description of the controller that QEMU will understand,
+ * to be used either on the command line or through the monitor.
+ *
+ * The description will be returned in @devstr and can be NULL, eg. when
+ * passing in one of the built-in controllers. The returned string must be
+ * freed by the caller.
+ *
+ * The number pointed to by @nusbcontroller will be increased by one every
+ * time the description for a USB controller has been generated successfully.
+ *
+ * Returns: 0 on success, <0 on failure
+ */
+int
qemuBuildControllerDevStr(const virDomainDef *domainDef,
virDomainControllerDefPtr def,
virQEMUCapsPtr qemuCaps,
+ char **devstr,
int *nusbcontroller)
{
virBuffer buf = VIR_BUFFER_INITIALIZER;
@@ -2532,11 +2553,11 @@ qemuBuildControllerDevStr(const virDomainDef *domainDef,
if (!qemuCheckCCWS390AddressSupport(domainDef, def->info, qemuCaps,
"controller"))
- return NULL;
+ return -1;
if (def->type == VIR_DOMAIN_CONTROLLER_TYPE_SCSI) {
if ((qemuDomainSetSCSIControllerModel(domainDef, qemuCaps, &model)) < 0)
- return NULL;
+ return -1;
}
if (!(def->type == VIR_DOMAIN_CONTROLLER_TYPE_SCSI &&
@@ -2544,22 +2565,22 @@ qemuBuildControllerDevStr(const virDomainDef *domainDef,
if (def->queues) {
virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
_("'queues' is only supported by virtio-scsi
controller"));
- return NULL;
+ return -1;
}
if (def->cmd_per_lun) {
virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
_("'cmd_per_lun' is only supported by virtio-scsi
controller"));
- return NULL;
+ return -1;
}
if (def->max_sectors) {
virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
_("'max_sectors' is only supported by virtio-scsi
controller"));
- return NULL;
+ return -1;
}
if (def->ioeventfd) {
virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
_("'ioeventfd' is only supported by virtio-scsi
controller"));
- return NULL;
+ return -1;
}
}
@@ -2954,11 +2975,12 @@ qemuBuildControllerDevStr(const virDomainDef *domainDef,
if (virBufferCheckError(&buf) < 0)
goto error;
- return virBufferContentAndReset(&buf);
+ *devstr = virBufferContentAndReset(&buf);
+ return 0;
error:
virBufferFreeAndReset(&buf);
- return NULL;
+ return -1;
}
@@ -3053,12 +3075,15 @@ qemuBuildControllerDevCommandLine(virCommandPtr cmd,
continue;
}
- virCommandAddArg(cmd, "-device");
- if (!(devstr = qemuBuildControllerDevStr(def, cont, qemuCaps,
- &usbcontroller)))
+ if (qemuBuildControllerDevStr(def, cont, qemuCaps,
+ &devstr, &usbcontroller) < 0)
return -1;
- virCommandAddArg(cmd, devstr);
- VIR_FREE(devstr);
+
+ if (devstr) {
+ virCommandAddArg(cmd, "-device");
+ virCommandAddArg(cmd, devstr);
+ VIR_FREE(devstr);
+ }
}
}
diff --git a/src/qemu/qemu_command.h b/src/qemu/qemu_command.h
index 69fe846..d8478f8 100644
--- a/src/qemu/qemu_command.h
+++ b/src/qemu/qemu_command.h
@@ -119,10 +119,11 @@ char *qemuBuildDriveDevStr(const virDomainDef *def,
virQEMUCapsPtr qemuCaps);
/* Current, best practice */
-char *qemuBuildControllerDevStr(const virDomainDef *domainDef,
- virDomainControllerDefPtr def,
- virQEMUCapsPtr qemuCaps,
- int *nusbcontroller);
+int qemuBuildControllerDevStr(const virDomainDef *domainDef,
+ virDomainControllerDefPtr def,
+ virQEMUCapsPtr qemuCaps,
+ char **devstr,
+ int *nusbcontroller);
int qemuBuildMemoryBackendStr(unsigned long long size,
unsigned long long pagesize,
diff --git a/src/qemu/qemu_hotplug.c b/src/qemu/qemu_hotplug.c
index 97fb272..8a23238 100644
--- a/src/qemu/qemu_hotplug.c
+++ b/src/qemu/qemu_hotplug.c
@@ -523,7 +523,10 @@ int qemuDomainAttachControllerDevice(virQEMUDriverPtr driver,
if (qemuAssignDeviceControllerAlias(vm->def, priv->qemuCaps, controller) <
0)
goto cleanup;
- if (!(devstr = qemuBuildControllerDevStr(vm->def, controller, priv->qemuCaps,
NULL)))
+ if (qemuBuildControllerDevStr(vm->def, controller, priv->qemuCaps, &devstr,
NULL) < 0)
+ goto cleanup;
+
+ if (!devstr)
goto cleanup;
if (VIR_REALLOC_N(vm->def->controllers, vm->def->ncontrollers+1) < 0)
--
2.7.4