[PATCH v3 10/19] qapi: introduce x-query-usb QMP command

[Daniel P . Berrangé]

This is a counterpart to the HMP "info usb" command. It is being
added with an "x-" prefix because this QMP command is intended as an
adhoc debugging tool and will thus not be modelled in QAPI as fully
structured data, nor will it have long term guaranteed stability.
The existing HMP command is rewritten to call the QMP command.

Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
---
 hw/usb/bus.c               | 36 +++++++++++++++++++++++++++---------
 qapi/machine.json          | 12 ++++++++++++
 stubs/usb-dev-stub.c       |  8 ++++++++
 tests/qtest/qmp-cmd-test.c |  2 ++
 4 files changed, 49 insertions(+), 9 deletions(-)

diff --git a/hw/usb/bus.c b/hw/usb/bus.c
index 07083349f5..17096e9e95 100644
--- a/hw/usb/bus.c
+++ b/hw/usb/bus.c
@@ -2,6 +2,8 @@
 #include "hw/qdev-properties.h"
 #include "hw/usb.h"
 #include "qapi/error.h"
+#include "qapi/qapi-commands-machine.h"
+#include "qapi/type-helpers.h"
 #include "qemu/error-report.h"
 #include "qemu/module.h"
 #include "sysemu/sysemu.h"
@@ -631,15 +633,16 @@ static char *usb_get_fw_dev_path(DeviceState *qdev)
     return fw_path;
 }
 
-void hmp_info_usb(Monitor *mon, const QDict *qdict)
+HumanReadableText *qmp_x_query_usb(Error **errp)
 {
+    g_autoptr(GString) buf = g_string_new("");
     USBBus *bus;
     USBDevice *dev;
     USBPort *port;
 
     if (QTAILQ_EMPTY(&busses)) {
-        monitor_printf(mon, "USB support not enabled\n");
-        return;
+        error_setg(errp, "USB support not enabled");
+        return NULL;
     }
 
     QTAILQ_FOREACH(bus, &busses, next) {
@@ -647,14 +650,29 @@ void hmp_info_usb(Monitor *mon, const QDict *qdict)
             dev = port->dev;
             if (!dev)
                 continue;
-            monitor_printf(mon, "  Device %d.%d, Port %s, Speed %s Mb/s, "
-                           "Product %s%s%s\n",
-                           bus->busnr, dev->addr, port->path,
-                           usb_speed(dev->speed), dev->product_desc,
-                           dev->qdev.id ? ", ID: " : "",
-                           dev->qdev.id ?: "");
+            g_string_append_printf(buf,
+                                   "  Device %d.%d, Port %s, Speed %s Mb/s, "
+                                   "Product %s%s%s\n",
+                                   bus->busnr, dev->addr, port->path,
+                                   usb_speed(dev->speed), dev->product_desc,
+                                   dev->qdev.id ? ", ID: " : "",
+                                   dev->qdev.id ?: "");
         }
     }
+
+    return human_readable_text_from_str(buf);
+}
+
+void hmp_info_usb(Monitor *mon, const QDict *qdict)
+{
+    Error *err = NULL;
+    g_autoptr(HumanReadableText) info = qmp_x_query_usb(&err);
+
+    if (err) {
+        error_report_err(err);
+        return;
+    }
+    monitor_printf(mon, "%s", info->human_readable_text);
 }
 
 /* handle legacy -usbdevice cmd line option */
diff --git a/qapi/machine.json b/qapi/machine.json
index c69a7ceef6..7450fa3ac1 100644
--- a/qapi/machine.json
+++ b/qapi/machine.json
@@ -1382,3 +1382,15 @@
 ##
 { 'command': 'x-query-roms',
   'returns': 'HumanReadableText' }
+
+##
+# @x-query-usb:
+#
+# Query information on the USB devices
+#
+# Returns: USB device information
+#
+# Since: 6.2
+##
+{ 'command': 'x-query-usb',
+  'returns': 'HumanReadableText' }
diff --git a/stubs/usb-dev-stub.c b/stubs/usb-dev-stub.c
index b1adeeb454..aa557692b7 100644
--- a/stubs/usb-dev-stub.c
+++ b/stubs/usb-dev-stub.c
@@ -8,6 +8,8 @@
 
 #include "qemu/osdep.h"
 #include "qemu/error-report.h"
+#include "qapi/error.h"
+#include "qapi/qapi-commands-machine.h"
 #include "sysemu/sysemu.h"
 #include "monitor/monitor.h"
 #include "hw/usb.h"
@@ -19,6 +21,12 @@ USBDevice *usbdevice_create(const char *driver)
     return NULL;
 }
 
+HumanReadableText *qmp_x_query_usb(Error **errp)
+{
+    error_setg(errp, "Support for USB devices not built-in");
+    return NULL;
+}
+
 void hmp_info_usb(Monitor *mon, const QDict *qdict)
 {
     monitor_printf(mon, "Support for USB devices not built-in\n");
diff --git a/tests/qtest/qmp-cmd-test.c b/tests/qtest/qmp-cmd-test.c
index fbd7ac10fb..15875a14c6 100644
--- a/tests/qtest/qmp-cmd-test.c
+++ b/tests/qtest/qmp-cmd-test.c
@@ -49,6 +49,8 @@ static int query_error_class(const char *cmd)
 #ifndef CONFIG_PROFILER
         { "x-query-profile", ERROR_CLASS_GENERIC_ERROR },
 #endif
+        /* Only valid with a USB bus added */
+        { "x-query-usb", ERROR_CLASS_GENERIC_ERROR },
         { NULL, -1 }
     };
     int i;
-- 
2.31.1