qemu: enable debug threads

When debug-threads is enabled, individual threads are given a separate
name (on Linux)

Fixes:
https://bugzilla.redhat.com/show_bug.cgi?id=1140121

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>

src/qemu/qemu_command.c

@@ -5332,6 +5332,30 @@ qemuAppendKeyWrapMachineParms(virBuffer *buf, virQEMUCapsPtr qemuCaps,
     return true;
 }
 
+static int
+qemuBuildNameCommandLine(virCommandPtr cmd,
+                         virQEMUDriverConfigPtr cfg,
+                         const virDomainDef *def,
+                         virQEMUCapsPtr qemuCaps)
+{
+    virBuffer buf = VIR_BUFFER_INITIALIZER;
+
+    virCommandAddArg(cmd, "-name");
+
+    virBufferAsprintf(&buf, "%s", def->name);
+
+    if (cfg->setProcessName &&
+        virQEMUCapsGet(qemuCaps, QEMU_CAPS_NAME_PROCESS))
+        virBufferAsprintf(&buf, ",process=qemu:%s", def->name);
+
+    if (virQEMUCapsGet(qemuCaps, QEMU_CAPS_NAME_DEBUG_THREADS))
+        virBufferAddLit(&buf, ",debug-threads=on");
+
+    virCommandAddArgBuffer(cmd, &buf);
+
+    return 0;
+}
+
 static int
 qemuBuildMachineCommandLine(virCommandPtr cmd,
                             const virDomainDef *def,
@@ -7192,14 +7216,8 @@ qemuBuildCommandLine(virConnectPtr conn,
 
     virCommandAddEnvPassCommon(cmd);
 
-    virCommandAddArg(cmd, "-name");
-    if (cfg->setProcessName &&
-        virQEMUCapsGet(qemuCaps, QEMU_CAPS_NAME_PROCESS)) {
-        virCommandAddArgFormat(cmd, "%s,process=qemu:%s",
-                               def->name, def->name);
-    } else {
-        virCommandAddArg(cmd, def->name);
-    }
+    if (qemuBuildNameCommandLine(cmd, cfg, def, qemuCaps) < 0)
+        goto error;
 
     if (!standalone)
         virCommandAddArg(cmd, "-S"); /* freeze CPU */

tests/qemuxml2argvdata/qemuxml2argv-debug-threads.args

@@ -0,0 +1,22 @@
+LC_ALL=C \
+PATH=/bin \
+HOME=/home/test \
+USER=test \
+LOGNAME=test \
+QEMU_AUDIO_DRV=none \
+/usr/bin/qemu \
+-name QEMUGuest1,debug-threads=on \
+-S \
+-M pc \
+-m 214 \
+-smp 1 \
+-uuid c7a5fdbd-edaf-9455-926a-d65c16db1809 \
+-nographic \
+-nodefaults \
+-monitor unix:/tmp/lib/domain--1-QEMUGuest1/monitor.sock,server,nowait \
+-no-acpi \
+-boot c \
+-usb \
+-drive file=/dev/HostVG/QEMUGuest1,format=raw,if=none,id=drive-ide0-0-0 \
+-device ide-drive,bus=ide.0,unit=0,drive=drive-ide0-0-0,id=ide0-0-0 \
+-device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x3

tests/qemuxml2argvdata/qemuxml2argv-debug-threads.xml

@@ -0,0 +1,34 @@
+<domain type='qemu'>
+  <name>QEMUGuest1</name>
+  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+  <title>A description of the test machine.</title>
+  <description>
+      A test of qemu&apos;s minimal configuration.
+      This test also tests the description and title elements.
+  </description>
+  <memory unit='KiB'>219100</memory>
+  <currentMemory unit='KiB'>219100</currentMemory>
+  <vcpu placement='static' cpuset='1-4,8-20,525'>1</vcpu>
+  <os>
+    <type arch='i686' machine='pc'>hvm</type>
+    <boot dev='hd'/>
+  </os>
+  <clock offset='utc'/>
+  <on_poweroff>destroy</on_poweroff>
+  <on_reboot>restart</on_reboot>
+  <on_crash>destroy</on_crash>
+  <devices>
+    <emulator>/usr/bin/qemu</emulator>
+    <disk type='block' device='disk'>
+      <source dev='/dev/HostVG/QEMUGuest1'/>
+      <target dev='hda' bus='ide'/>
+      <address type='drive' controller='0' bus='0' target='0' unit='0'/>
+    </disk>
+    <controller type='usb' index='0'/>
+    <controller type='ide' index='0'/>
+    <controller type='pci' index='0' model='pci-root'/>
+    <input type='mouse' bus='ps2'/>
+    <input type='keyboard' bus='ps2'/>
+    <memballoon model='virtio'/>
+  </devices>
+</domain>

tests/qemuxml2argvtest.c

@@ -1893,6 +1893,8 @@ mymain(void)
                               VIR_DOMAIN_DEF_PARSE_SKIP_OSTYPE_CHECKS,
                               NONE);
 
+    DO_TEST("debug-threads", QEMU_CAPS_NAME_DEBUG_THREADS);
+
     qemuTestDriverFree(&driver);
 
     return ret == 0 ? EXIT_SUCCESS : EXIT_FAILURE;