qemuhotplugtest: Add tests for USB disk hotplug

tests/qemuhotplugtest.c

@@ -442,6 +442,23 @@ mymain(void)
                    "device_del", QMP_DEVICE_DELETED("virtio-disk4") QMP_OK,
                    "human-monitor-command", HMP(""));
 
+    DO_TEST_ATTACH("hotplug-base", "disk-usb", false, true,
+                   "human-monitor-command", HMP("OK\\r\\n"),
+                   "device_add", QMP_OK);
+    DO_TEST_DETACH("hotplug-base", "disk-usb", false, false,
+                   "device_del", QMP_OK,
+                   "human-monitor-command", HMP(""));
+
+    DO_TEST_ATTACH_EVENT("hotplug-base", "disk-usb", false, true,
+                         "human-monitor-command", HMP("OK\\r\\n"),
+                         "device_add", QMP_OK);
+    DO_TEST_DETACH("hotplug-base", "disk-usb", true, true,
+                   "device_del", QMP_OK,
+                   "human-monitor-command", HMP(""));
+    DO_TEST_DETACH("hotplug-base", "disk-usb", false, false,
+                   "device_del", QMP_DEVICE_DELETED("usb-disk16") QMP_OK,
+                   "human-monitor-command", HMP(""));
+
     virObjectUnref(driver.caps);
     virObjectUnref(driver.xmlopt);
     virObjectUnref(driver.config);

tests/qemuhotplugtestdata/qemuhotplug-disk-usb.xml

+<disk type='file' device='disk'>
+  <driver name='qemu' type='raw' cache='none'/>
+  <source file='/dev/null'/>
+  <target dev='sdq' bus='usb'/>
+  <readonly/>
+  <shareable/>
+</disk>

tests/qemuhotplugtestdata/qemuhotplug-hotplug-base+disk-usb.xml

+<domain type='kvm'>
+  <name>hotplug</name>
+  <uuid>d091ea82-29e6-2e34-3005-f02617b36e87</uuid>
+  <memory unit='KiB'>4194304</memory>
+  <currentMemory unit='KiB'>4194304</currentMemory>
+  <vcpu placement='static'>4</vcpu>
+  <os>
+    <type arch='x86_64' machine='pc'>hvm</type>
+    <boot dev='hd'/>
+  </os>
+  <features>
+    <acpi/>
+    <apic/>
+    <pae/>
+  </features>
+  <clock offset='utc'/>
+  <on_poweroff>destroy</on_poweroff>
+  <on_reboot>restart</on_reboot>
+  <on_crash>restart</on_crash>
+  <devices>
+    <emulator>/usr/libexec/qemu-kvm</emulator>
+    <disk type='file' device='disk'>
+      <driver name='qemu' type='raw' cache='none'/>
+      <source file='/dev/null'/>
+      <target dev='sdq' bus='usb'/>
+      <readonly/>
+      <shareable/>
+    </disk>
+    <controller type='usb' index='0'>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x2'/>
+    </controller>
+    <controller type='ide' index='0'>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x1'/>
+    </controller>
+    <controller type='scsi' index='0' model='virtio-scsi'>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>
+    </controller>
+    <controller type='pci' index='0' model='pci-root'/>
+    <controller type='virtio-serial' index='0'>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/>
+    </controller>
+    <memballoon model='none'/>
+  </devices>
+  <seclabel type='none'/>
+</domain>