[RFC PATCH 1/2] conf: Introduce 'absolute' clock offset
Peter Krempa
pkrempa at redhat.com
Tue Apr 26 15:34:21 UTC 2022
The 'absolute' clock offset type has a 'start' attribute which is an
unix epoch timestamp to which the hardware clock is always set at start
of the VM.
This is useful if some VM needs to be kept set to an arbitrary time for
e.g. testing or working around broken software.
Signed-off-by: Peter Krempa <pkrempa at redhat.com>
---
docs/formatdomain.rst | 4 ++
src/conf/domain_conf.c | 13 +++++++
src/conf/domain_conf.h | 4 ++
src/conf/schemas/domaincommon.rng | 8 ++++
src/libxl/libxl_conf.c | 1 +
tests/qemuxml2argvdata/clock-absolute.xml | 30 +++++++++++++++
.../clock-absolute.x86_64-latest.xml | 38 +++++++++++++++++++
tests/qemuxml2xmltest.c | 1 +
8 files changed, 99 insertions(+)
create mode 100644 tests/qemuxml2argvdata/clock-absolute.xml
create mode 100644 tests/qemuxml2xmloutdata/clock-absolute.x86_64-latest.xml
diff --git a/docs/formatdomain.rst b/docs/formatdomain.rst
index 9be305f3e6..5639a3014b 100644
--- a/docs/formatdomain.rst
+++ b/docs/formatdomain.rst
@@ -2170,6 +2170,10 @@ Windows, however, expects it to be in so called 'localtime'.
the RTC adjustments are lost at each reboot. :since:`Since 0.7.7`
:since:`Since 0.9.11` the ``basis`` attribute can be either 'utc'
(default) or 'localtime'.
+ ``absolute``
+ The guest clock will be always set to the value of the ``start``
+ attribute. The ``start`` attribute takes the an epoch timestamp.
+ :since:`Since 8.4.0`.
A ``clock`` may have zero or more ``timer`` sub-elements. :since:`Since
0.8.0`
diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index bd2884088c..d0c88e6d7f 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -1171,6 +1171,7 @@ VIR_ENUM_IMPL(virDomainClockOffset,
"localtime",
"variable",
"timezone",
+ "absolute",
);
VIR_ENUM_IMPL(virDomainClockBasis,
@@ -19412,6 +19413,15 @@ virDomainDefClockParse(virDomainDef *def,
return -1;
}
break;
+
+ case VIR_DOMAIN_CLOCK_OFFSET_ABSOLUTE:
+ if (virXPathULongLong("number(./clock/@start)", ctxt,
+ &def->clock.data.starttime) < 0) {
+ virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+ _("missing 'start' attribute for clock with offset='absolute'"));
+ return -1;
+ }
+ break;
}
if ((n = virXPathNodeSet("./clock/timer", ctxt, &nodes)) < 0)
@@ -26202,6 +26212,9 @@ virDomainClockDefFormat(virBuffer *buf,
case VIR_DOMAIN_CLOCK_OFFSET_TIMEZONE:
virBufferEscapeString(&clockAttr, " timezone='%s'", def->data.timezone);
break;
+ case VIR_DOMAIN_CLOCK_OFFSET_ABSOLUTE:
+ virBufferAsprintf(&clockAttr, " start='%llu'", def->data.starttime);
+ break;
}
for (n = 0; n < def->ntimers; n++) {
diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h
index 88a411d00c..3bdf4b51b1 100644
--- a/src/conf/domain_conf.h
+++ b/src/conf/domain_conf.h
@@ -2449,6 +2449,7 @@ typedef enum {
VIR_DOMAIN_CLOCK_OFFSET_LOCALTIME = 1,
VIR_DOMAIN_CLOCK_OFFSET_VARIABLE = 2,
VIR_DOMAIN_CLOCK_OFFSET_TIMEZONE = 3,
+ VIR_DOMAIN_CLOCK_OFFSET_ABSOLUTE = 4,
VIR_DOMAIN_CLOCK_OFFSET_LAST
} virDomainClockOffsetType;
@@ -2483,6 +2484,9 @@ struct _virDomainClockDef {
/* Timezone name, when
* offset == VIR_DOMAIN_CLOCK_OFFSET_LOCALTIME */
char *timezone;
+
+ /* absolute clock start time for VIR_DOMAIN_CLOCK_OFFSET_ABSOLUTE */
+ unsigned long long starttime;
} data;
size_t ntimers;
diff --git a/src/conf/schemas/domaincommon.rng b/src/conf/schemas/domaincommon.rng
index 8afb0dadd4..d0c9ea7973 100644
--- a/src/conf/schemas/domaincommon.rng
+++ b/src/conf/schemas/domaincommon.rng
@@ -1252,6 +1252,14 @@
</attribute>
</optional>
</group>
+ <group>
+ <attribute name="offset">
+ <value>absolute</value>
+ </attribute>
+ <attribute name="start">
+ <ref name="unsignedInt"/>
+ </attribute>
+ </group>
</choice>
<zeroOrMore>
<ref name="timer"/>
diff --git a/src/libxl/libxl_conf.c b/src/libxl/libxl_conf.c
index 6398129195..a0d4ba51ba 100644
--- a/src/libxl/libxl_conf.c
+++ b/src/libxl/libxl_conf.c
@@ -391,6 +391,7 @@ libxlMakeDomBuildInfo(virDomainDef *def,
virDomainClockOffsetTypeToString(clock.offset));
return -1;
+ case VIR_DOMAIN_CLOCK_OFFSET_ABSOLUTE:
case VIR_DOMAIN_CLOCK_OFFSET_LAST:
default:
virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
diff --git a/tests/qemuxml2argvdata/clock-absolute.xml b/tests/qemuxml2argvdata/clock-absolute.xml
new file mode 100644
index 0000000000..e79f53ed3c
--- /dev/null
+++ b/tests/qemuxml2argvdata/clock-absolute.xml
@@ -0,0 +1,30 @@
+<domain type='qemu'>
+ <name>QEMUGuest1</name>
+ <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+ <memory unit='KiB'>219100</memory>
+ <currentMemory unit='KiB'>219100</currentMemory>
+ <vcpu placement='static'>1</vcpu>
+ <os>
+ <type arch='x86_64' machine='pc'>hvm</type>
+ <boot dev='hd'/>
+ </os>
+ <clock offset='absolute' start='1234'/>
+ <on_poweroff>destroy</on_poweroff>
+ <on_reboot>restart</on_reboot>
+ <on_crash>destroy</on_crash>
+ <devices>
+ <emulator>/usr/bin/qemu-system-x86_64</emulator>
+ <disk type='block' device='disk'>
+ <driver name='qemu' type='raw'/>
+ <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='none'/>
+ </devices>
+</domain>
diff --git a/tests/qemuxml2xmloutdata/clock-absolute.x86_64-latest.xml b/tests/qemuxml2xmloutdata/clock-absolute.x86_64-latest.xml
new file mode 100644
index 0000000000..b313a74039
--- /dev/null
+++ b/tests/qemuxml2xmloutdata/clock-absolute.x86_64-latest.xml
@@ -0,0 +1,38 @@
+<domain type='qemu'>
+ <name>QEMUGuest1</name>
+ <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+ <memory unit='KiB'>219100</memory>
+ <currentMemory unit='KiB'>219100</currentMemory>
+ <vcpu placement='static'>1</vcpu>
+ <os>
+ <type arch='x86_64' machine='pc'>hvm</type>
+ <boot dev='hd'/>
+ </os>
+ <cpu mode='custom' match='exact' check='none'>
+ <model fallback='forbid'>qemu64</model>
+ </cpu>
+ <clock offset='absolute' start='1234'/>
+ <on_poweroff>destroy</on_poweroff>
+ <on_reboot>restart</on_reboot>
+ <on_crash>destroy</on_crash>
+ <devices>
+ <emulator>/usr/bin/qemu-system-x86_64</emulator>
+ <disk type='block' device='disk'>
+ <driver name='qemu' type='raw'/>
+ <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' model='piix3-uhci'>
+ <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='pci' index='0' model='pci-root'/>
+ <input type='mouse' bus='ps2'/>
+ <input type='keyboard' bus='ps2'/>
+ <audio id='1' type='none'/>
+ <memballoon model='none'/>
+ </devices>
+</domain>
diff --git a/tests/qemuxml2xmltest.c b/tests/qemuxml2xmltest.c
index 58ee29cd33..ea524685b2 100644
--- a/tests/qemuxml2xmltest.c
+++ b/tests/qemuxml2xmltest.c
@@ -274,6 +274,7 @@ mymain(void)
DO_TEST_NOCAPS("clock-timer-hyperv-rtc");
DO_TEST_CAPS_ARCH_LATEST("clock-timer-armvtimer", "aarch64");
DO_TEST_NOCAPS("clock-realtime");
+ DO_TEST_CAPS_LATEST("clock-absolute");
DO_TEST_NOCAPS("cpu-eoi-disabled");
DO_TEST_NOCAPS("cpu-eoi-enabled");
--
2.35.1
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