qemu: Implement 'absolute' clock offset mode

Add support for the mode and add the corresponding qemuxml2argv test
case.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>

src/qemu/qemu_command.c

@@ -6140,7 +6140,7 @@ qemuBuildClockArgStr(virDomainClockDef *def)
     size_t i;
     g_auto(virBuffer) buf = VIR_BUFFER_INITIALIZER;
 
-    switch (def->offset) {
+    switch ((virDomainClockOffsetType) def->offset) {
     case VIR_DOMAIN_CLOCK_OFFSET_UTC:
         virBufferAddLit(&buf, "base=utc");
         break;
@@ -6190,6 +6190,14 @@ qemuBuildClockArgStr(virDomainClockDef *def)
         virBufferAsprintf(&buf, "base=%s", thenstr);
     }   break;
 
+    case VIR_DOMAIN_CLOCK_OFFSET_ABSOLUTE: {
+        g_autoptr(GDateTime) then = g_date_time_new_from_unix_utc(def->data.starttime);
+        g_autofree char *thenstr = g_date_time_format(then, "%Y-%m-%dT%H:%M:%S");
+
+        virBufferAsprintf(&buf, "base=%s", thenstr);
+    }   break;
+
+    case VIR_DOMAIN_CLOCK_OFFSET_LAST:
     default:
         virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
                        _("unsupported clock offset '%s'"),

tests/qemuxml2argvdata/clock-absolute.x86_64-latest.args

@@ -0,0 +1,36 @@
+LC_ALL=C \
+PATH=/bin \
+HOME=/tmp/lib/domain--1-QEMUGuest1 \
+USER=test \
+LOGNAME=test \
+XDG_DATA_HOME=/tmp/lib/domain--1-QEMUGuest1/.local/share \
+XDG_CACHE_HOME=/tmp/lib/domain--1-QEMUGuest1/.cache \
+XDG_CONFIG_HOME=/tmp/lib/domain--1-QEMUGuest1/.config \
+/usr/bin/qemu-system-x86_64 \
+-name guest=QEMUGuest1,debug-threads=on \
+-S \
+-object '{"qom-type":"secret","id":"masterKey0","format":"raw","file":"/tmp/lib/domain--1-QEMUGuest1/master-key.aes"}' \
+-machine pc,usb=off,dump-guest-core=off,memory-backend=pc.ram \
+-accel tcg \
+-cpu qemu64 \
+-m 214 \
+-object '{"qom-type":"memory-backend-ram","id":"pc.ram","size":224395264}' \
+-overcommit mem-lock=off \
+-smp 1,sockets=1,cores=1,threads=1 \
+-uuid c7a5fdbd-edaf-9455-926a-d65c16db1809 \
+-display none \
+-no-user-config \
+-nodefaults \
+-chardev socket,id=charmonitor,fd=1729,server=on,wait=off \
+-mon chardev=charmonitor,id=monitor,mode=control \
+-rtc base=1970-01-01T00:20:34 \
+-no-shutdown \
+-no-acpi \
+-boot strict=on \
+-device '{"driver":"piix3-usb-uhci","id":"usb","bus":"pci.0","addr":"0x1.0x2"}' \
+-blockdev '{"driver":"host_device","filename":"/dev/HostVG/QEMUGuest1","node-name":"libvirt-1-storage","auto-read-only":true,"discard":"unmap"}' \
+-blockdev '{"node-name":"libvirt-1-format","read-only":false,"driver":"raw","file":"libvirt-1-storage"}' \
+-device '{"driver":"ide-hd","bus":"ide.0","unit":0,"drive":"libvirt-1-format","id":"ide0-0-0","bootindex":1}' \
+-audiodev '{"id":"audio1","driver":"none"}' \
+-sandbox on,obsolete=deny,elevateprivileges=deny,spawn=deny,resourcecontrol=deny \
+-msg timestamp=on

tests/qemuxml2argvtest.c

@@ -1213,6 +1213,7 @@ mymain(void)
     DO_TEST("kvmclock", QEMU_CAPS_KVM);
     DO_TEST("clock-timer-hyperv-rtc", QEMU_CAPS_KVM);
     DO_TEST_NOCAPS("clock-realtime");
+    DO_TEST_CAPS_LATEST("clock-absolute");
 
     DO_TEST_CAPS_LATEST("controller-usb-order");