Allow configurable timezones with QEMU

Allow an arbitrary timezone with QEMU by setting the $TZ environment
variable when launching QEMU

* src/qemu/qemu_conf.c: Set TZ environment variable if a timezone
  is requested
* tests/qemuxml2argvtest.c: Add test case for timezones
* tests/qemuxml2argvdata/qemuxml2argv-clock-france.xml,
  tests/qemuxml2argvdata/qemuxml2argv-clock-france.args: Data
  for timezone tests

src/qemu/qemu_conf.c

@@ -3071,6 +3071,7 @@ qemuBuildClockArgStr(virDomainClockDefPtr def)
         break;
 
     case VIR_DOMAIN_CLOCK_OFFSET_LOCALTIME:
+    case VIR_DOMAIN_CLOCK_OFFSET_TIMEZONE:
         virBufferAddLit(&buf, "base=localtime");
         break;
 
@@ -3550,6 +3551,7 @@ int qemudBuildCommandLine(virConnectPtr conn,
     } else {
         switch (def->clock.offset) {
         case VIR_DOMAIN_CLOCK_OFFSET_LOCALTIME:
+        case VIR_DOMAIN_CLOCK_OFFSET_TIMEZONE:
             ADD_ARG_LIT("-localtime");
             break;
 
@@ -3564,6 +3566,10 @@ int qemudBuildCommandLine(virConnectPtr conn,
             goto error;
         }
     }
+    if (def->clock.offset == VIR_DOMAIN_CLOCK_OFFSET_TIMEZONE &&
+        def->clock.data.timezone) {
+        ADD_ENV_PAIR("TZ", def->clock.data.timezone);
+    }
 
     if ((qemuCmdFlags & QEMUD_CMD_FLAG_NO_REBOOT) &&
         def->onReboot != VIR_DOMAIN_LIFECYCLE_RESTART)

tests/qemuxml2argvdata/qemuxml2argv-clock-france.args

+LC_ALL=C PATH=/bin HOME=/home/test USER=test LOGNAME=test TZ=Europe/Paris /usr/bin/qemu -S -M pc -m 214 -smp 1 -nographic -monitor unix:/tmp/test-monitor,server,nowait -rtc base=localtime -no-acpi -boot c -hda /dev/HostVG/QEMUGuest1 -net none -serial none -parallel none -usb

tests/qemuxml2argvdata/qemuxml2argv-clock-france.xml

+<domain type='qemu'>
+  <name>QEMUGuest1</name>
+  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+  <memory>219200</memory>
+  <currentMemory>219200</currentMemory>
+  <vcpu>1</vcpu>
+  <os>
+    <type arch='i686' machine='pc'>hvm</type>
+    <boot dev='hd'/>
+  </os>
+  <clock offset='timezone' timezone='Europe/Paris'/>
+  <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' unit='0'/>
+    </disk>
+    <controller type='ide' index='0'/>
+  </devices>
+</domain>

tests/qemuxml2argvtest.c

@@ -230,6 +230,8 @@ mymain(int argc, char **argv)
      * Can't be enabled since the absolute timestamp changes every time
     DO_TEST("clock-variable", QEMUD_CMD_FLAG_RTC);
     */
+    DO_TEST("clock-france", QEMUD_CMD_FLAG_RTC);
+
     DO_TEST("hugepages", QEMUD_CMD_FLAG_MEM_PATH);
     DO_TEST("disk-cdrom", 0);
     DO_TEST("disk-cdrom-empty", QEMUD_CMD_FLAG_DRIVE);