10:12 a.m.
From: Eric Blake <eblake(a)redhat.com>
Each <domainsnapshot> can now contain an optional <memory>
element that describes how the VM state was handled, similar
to disk snapshots. The new element will always appear in
output; for back-compat, an input that lacks the element will
assume 'no' or 'internal' according to the domain state.
Along with this change, it is now possible to pass <disks> in
the XML for an offline snapshot; this also needs to be wired up
in a future patch, to make it possible to choose internal vs.
external on a per-disk basis for each disk in an offline domain.
At that point, using the --disk-only flag for an offline domain
will be able to work.
For some examples below, remember that qemu supports the
following snapshot actions:
qemu-img: offline external and internal disk
savevm: online internal VM and disk
migrate: online external VM
transaction: online external disk
=====
<domainsnapshot>
<memory snapshot='no'/>
...
</domainsnapshot>
implies that there is no VM state saved (mandatory for
offline and disk-only snapshots, not possible otherwise);
using qemu-img for offline domains and transaction for online.
=====
<domainsnapshot>
<memory snapshot='internal'/>
...
</domainsnapshot>
state is saved inside one of the disks (as in qemu's 'savevm'
system checkpoint implementation). If needed in the future,
we can also add an attribute pointing out _which_ disk saved
the internal state; maybe disk='vda'.
=====
<domainsnapshot>
<memory snapshot='external' file='/path/to/state'/>
...
</domainsnapshot>
This is not wired up yet, but future patches will allow this to
control a combination of 'virsh save /path/to/state' plus disk
snapshots from the same point in time.
=====
So for 0.10.2, I plan to implement this table of combinations,
with '*' designating new code and '+' designating existing code
reached through new combinations of xml and/or the existing
DISK_ONLY flag:
domain memory disk disk-only | result
-----------------------------------------
offline omit omit any | memory=no disk=int, via qemu-img
offline no omit any |+memory=no disk=int, via qemu-img
offline omit/no no any | invalid combination (nothing to snapshot)
offline omit/no int any |+memory=no disk=int, via qemu-img
offline omit/no ext any |*memory=no disk=ext, via qemu-img
offline int/ext any any | invalid combination (no memory to save)
online omit omit off | memory=int disk=int, via savevm
online omit omit on | memory=no disk=default, via transaction
online omit no/ext off | unsupported for now
online omit no on | invalid combination (nothing to snapshot)
online omit ext on | memory=no disk=ext, via transaction
online omit int off |+memory=int disk=int, via savevm
online omit int on | unsupported for now
online no omit any |+memory=no disk=default, via transaction
online no no any | invalid combination (nothing to snapshot)
online no int any | unsupported for now
online no ext any |+memory=no disk=ext, via transaction
online int/ext any on | invalid combination (disk-only vs. memory)
online int omit off |+memory=int disk=int, via savevm
online int no/ext off | unsupported for now
online int int off |+memory=int disk=int, via savevm
online ext omit off |*memory=ext disk=default, via migrate+trans
online ext no off |+memory=ext disk=no, via migrate
online ext int off | unsupported for now
online ext ext off |*memory=ext disk=ext, via migrate+transaction
* docs/schemas/domainsnapshot.rng (memory): New RNG element.
* docs/formatsnapshot.html.in: Document it.
* src/conf/snapshot_conf.h (virDomainSnapshotDef): New fields.
* src/conf/domain_conf.c (virDomainSnapshotDefFree)
(virDomainSnapshotDefParseString, virDomainSnapshotDefFormat):
Manage new fields.
* tests/domainsnapshotxml2xmltest.c: New test.
* tests/domainsnapshotxml2xmlin/*.xml: Update existing tests.
* tests/domainsnapshotxml2xmlout/*.xml: Likewise.
---
docs/formatsnapshot.html.in | 11 ++++
docs/schemas/domainsnapshot.rng | 23 ++++++++
src/conf/snapshot_conf.c | 66 +++++++++++++++++-----
src/conf/snapshot_conf.h | 4 ++
tests/domainsnapshotxml2xmlin/external_vm.xml | 10 ++++
tests/domainsnapshotxml2xmlin/noparent.xml | 9 +++
tests/domainsnapshotxml2xmlout/all_parameters.xml | 1 +
tests/domainsnapshotxml2xmlout/disk_snapshot.xml | 1 +
tests/domainsnapshotxml2xmlout/external_vm.xml | 43 ++++++++++++++
tests/domainsnapshotxml2xmlout/full_domain.xml | 1 +
tests/domainsnapshotxml2xmlout/metadata.xml | 1 +
tests/domainsnapshotxml2xmlout/noparent.xml | 1 +
.../noparent_nodescription.xml | 1 +
.../noparent_nodescription_noactive.xml | 1 +
tests/domainsnapshotxml2xmltest.c | 1 +
15 files changed, 161 insertions(+), 13 deletions(-)
create mode 100644 tests/domainsnapshotxml2xmlin/external_vm.xml
create mode 100644 tests/domainsnapshotxml2xmlin/noparent.xml
create mode 100644 tests/domainsnapshotxml2xmlout/external_vm.xml
diff --git a/docs/formatsnapshot.html.in b/docs/formatsnapshot.html.in
index ec5ebf3..2af32bc 100644
--- a/docs/formatsnapshot.html.in
+++ b/docs/formatsnapshot.html.in
@@ -106,6 +106,17 @@
description is omitted when initially creating the snapshot,
then this field will be empty.
</dd>
+ <dt><code>memory</code></dt>
+ <dd>On input, this is an optional request for how to handle VM
+ state. For an offline domain or a disk-only snapshot,
+ attribute <code>snapshot</code> must be <code>no</code>,
since
+ there is no VM state saved; otherwise, the attribute can
+ be <code>internal</code> if the VM state is piggy-backed with
+ other internal disk state, or <code>external</code> along with
+ a second attribute <code>file</code> giving the absolute path
+ of the file holding the VM state. <span class="since">Since
+ 0.10.2</span>
+ </dd>
<dt><code>disks</code></dt>
<dd>On input, this is an optional listing of specific
instructions for disk snapshots; it is needed when making a
diff --git a/docs/schemas/domainsnapshot.rng b/docs/schemas/domainsnapshot.rng
index ecaafe9..45d55b5 100644
--- a/docs/schemas/domainsnapshot.rng
+++ b/docs/schemas/domainsnapshot.rng
@@ -31,6 +31,29 @@
</element>
</optional>
<optional>
+ <element name='memory'>
+ <choice>
+ <attribute name='snapshot'>
+ <choice>
+ <value>no</value>
+ <value>internal</value>
+ </choice>
+ </attribute>
+ <group>
+ <optional>
+ <attribute name='snapshot'>
+ <value>external</value>
+ </attribute>
+ </optional>
+ <attribute name='file'>
+ <ref name='absFilePath'/>
+ </attribute>
+ </group>
+ </choice>
+ <empty/>
+ </element>
+ </optional>
+ <optional>
<element name='disks'>
<zeroOrMore>
<ref name='disksnapshot'/>
diff --git a/src/conf/snapshot_conf.c b/src/conf/snapshot_conf.c
index 16c844d..6f77026 100644
--- a/src/conf/snapshot_conf.c
+++ b/src/conf/snapshot_conf.c
@@ -94,6 +94,7 @@ void virDomainSnapshotDefFree(virDomainSnapshotDefPtr def)
VIR_FREE(def->name);
VIR_FREE(def->description);
VIR_FREE(def->parent);
+ VIR_FREE(def->file);
for (i = 0; i < def->ndisks; i++)
virDomainSnapshotDiskDefClear(&def->disks[i]);
VIR_FREE(def->disks);
@@ -182,6 +183,9 @@ virDomainSnapshotDefParseString(const char *xmlStr,
int active;
char *tmp;
int keepBlanksDefault = xmlKeepBlanksDefault(0);
+ char *memorySnapshot = NULL;
+ char *memoryFile = NULL;
+ bool offline = !!(flags & VIR_DOMAIN_SNAPSHOT_PARSE_OFFLINE);
xml = virXMLParseCtxt(NULL, xmlStr, _("(domain_snapshot)"), &ctxt);
if (!xml) {
@@ -208,15 +212,11 @@ virDomainSnapshotDefParseString(const char *xmlStr,
virReportError(VIR_ERR_XML_ERROR, "%s",
_("a redefined snapshot must have a name"));
goto cleanup;
- } else {
- ignore_value(virAsprintf(&def->name, "%lld",
- (long long)tv.tv_sec));
}
- }
-
- if (def->name == NULL) {
- virReportOOMError();
- goto cleanup;
+ if (virAsprintf(&def->name, "%lld", (long long)tv.tv_sec) <
0) {
+ virReportOOMError();
+ goto cleanup;
+ }
}
def->description = virXPathString("string(./description)", ctxt);
@@ -247,6 +247,8 @@ virDomainSnapshotDefParseString(const char *xmlStr,
state);
goto cleanup;
}
+ offline = (def->state == VIR_DOMAIN_SHUTOFF ||
+ def->state == VIR_DOMAIN_DISK_SNAPSHOT);
/* Older snapshots were created with just <domain>/<uuid>, and
* lack domain/@type. In that case, leave dom NULL, and
@@ -274,11 +276,42 @@ virDomainSnapshotDefParseString(const char *xmlStr,
def->creationTime = tv.tv_sec;
}
+ memorySnapshot = virXPathString("string(./memory/@snapshot)", ctxt);
+ memoryFile = virXPathString("string(./memory/@file)", ctxt);
+ if (memorySnapshot) {
+ def->memory = virDomainSnapshotLocationTypeFromString(memorySnapshot);
+ if (def->memory <= 0) {
+ virReportError(VIR_ERR_XML_ERROR,
+ _("unknown memory snapshot setting '%s'"),
+ memorySnapshot);
+ goto cleanup;
+ }
+ if (memoryFile &&
+ def->memory != VIR_DOMAIN_SNAPSHOT_LOCATION_EXTERNAL) {
+ virReportError(VIR_ERR_XML_ERROR,
+ _("memory filename '%s' requires external
snapshot"),
+ memoryFile);
+ goto cleanup;
+ }
+ } else if (memoryFile) {
+ def->memory = VIR_DOMAIN_SNAPSHOT_LOCATION_EXTERNAL;
+ } else if (flags & VIR_DOMAIN_SNAPSHOT_PARSE_REDEFINE) {
+ def->memory = (offline ?
+ VIR_DOMAIN_SNAPSHOT_LOCATION_NONE :
+ VIR_DOMAIN_SNAPSHOT_LOCATION_INTERNAL);
+ }
+ if (offline && def->memory &&
+ def->memory != VIR_DOMAIN_SNAPSHOT_LOCATION_NONE) {
+ virReportError(VIR_ERR_XML_ERROR, "%s",
+ _("memory state cannot be saved with offline
snapshot"));
+ goto cleanup;
+ }
+ def->file = memoryFile;
+ memoryFile = NULL;
+
if ((i = virXPathNodeSet("./disks/*", ctxt, &nodes)) < 0)
goto cleanup;
- if (flags & VIR_DOMAIN_SNAPSHOT_PARSE_DISKS ||
- (flags & VIR_DOMAIN_SNAPSHOT_PARSE_REDEFINE &&
- def->state == VIR_DOMAIN_DISK_SNAPSHOT)) {
+ if (flags & VIR_DOMAIN_SNAPSHOT_PARSE_DISKS) {
def->ndisks = i;
if (def->ndisks && VIR_ALLOC_N(def->disks, def->ndisks) < 0)
{
virReportOOMError();
@@ -310,6 +343,8 @@ cleanup:
VIR_FREE(creation);
VIR_FREE(state);
VIR_FREE(nodes);
+ VIR_FREE(memorySnapshot);
+ VIR_FREE(memoryFile);
xmlXPathFreeContext(ctxt);
if (ret == NULL)
virDomainSnapshotDefFree(def);
@@ -531,8 +566,13 @@ char *virDomainSnapshotDefFormat(const char *domain_uuid,
}
virBufferAsprintf(&buf, "
<creationTime>%lld</creationTime>\n",
def->creationTime);
- /* For now, only output <disks> on disk-snapshot */
- if (def->state == VIR_DOMAIN_DISK_SNAPSHOT) {
+ if (def->memory) {
+ virBufferAsprintf(&buf, " <memory snapshot='%s'",
+ virDomainSnapshotLocationTypeToString(def->memory));
+ virBufferEscapeString(&buf, " file='%s'", def->file);
+ virBufferAddLit(&buf, "/>\n");
+ }
+ if (def->ndisks) {
virBufferAddLit(&buf, " <disks>\n");
for (i = 0; i < def->ndisks; i++) {
virDomainSnapshotDiskDefPtr disk = &def->disks[i];
diff --git a/src/conf/snapshot_conf.h b/src/conf/snapshot_conf.h
index c00347f..00775ae 100644
--- a/src/conf/snapshot_conf.h
+++ b/src/conf/snapshot_conf.h
@@ -66,6 +66,9 @@ struct _virDomainSnapshotDef {
long long creationTime; /* in seconds */
int state; /* enum virDomainSnapshotState */
+ int memory; /* enum virDomainMemorySnapshot */
+ char *file; /* memory state file when snapshot is external */
+
size_t ndisks; /* should not exceed dom->ndisks */
virDomainSnapshotDiskDef *disks;
@@ -93,6 +96,7 @@ typedef enum {
VIR_DOMAIN_SNAPSHOT_PARSE_REDEFINE = 1 << 0,
VIR_DOMAIN_SNAPSHOT_PARSE_DISKS = 1 << 1,
VIR_DOMAIN_SNAPSHOT_PARSE_INTERNAL = 1 << 2,
+ VIR_DOMAIN_SNAPSHOT_PARSE_OFFLINE = 1 << 3,
} virDomainSnapshotParseFlags;
virDomainSnapshotDefPtr virDomainSnapshotDefParseString(const char *xmlStr,
diff --git a/tests/domainsnapshotxml2xmlin/external_vm.xml
b/tests/domainsnapshotxml2xmlin/external_vm.xml
new file mode 100644
index 0000000..3bcd150
--- /dev/null
+++ b/tests/domainsnapshotxml2xmlin/external_vm.xml
@@ -0,0 +1,10 @@
+<domainsnapshot>
+ <name>my snap name</name>
+ <description>!@#$%^</description>
+ <state>running</state>
+ <memory snapshot='external' file='/dev/HostVG/GuestMemory'/>
+ <parent>
+ <name>earlier_snap</name>
+ </parent>
+ <creationTime>1272917631</creationTime>
+</domainsnapshot>
diff --git a/tests/domainsnapshotxml2xmlin/noparent.xml
b/tests/domainsnapshotxml2xmlin/noparent.xml
new file mode 100644
index 0000000..cbac0d8
--- /dev/null
+++ b/tests/domainsnapshotxml2xmlin/noparent.xml
@@ -0,0 +1,9 @@
+<domainsnapshot>
+ <name>my snap name</name>
+ <description>!@#$%^</description>
+ <state>running</state>
+ <creationTime>1272917631</creationTime>
+ <domain>
+ <uuid>9d37b878-a7cc-9f9a-b78f-49b3abad25a8</uuid>
+ </domain>
+</domainsnapshot>
diff --git a/tests/domainsnapshotxml2xmlout/all_parameters.xml
b/tests/domainsnapshotxml2xmlout/all_parameters.xml
index eb2ee85..4178ac6 100644
--- a/tests/domainsnapshotxml2xmlout/all_parameters.xml
+++ b/tests/domainsnapshotxml2xmlout/all_parameters.xml
@@ -6,6 +6,7 @@
<name>earlier_snap</name>
</parent>
<creationTime>1272917631</creationTime>
+ <memory snapshot='internal'/>
<domain>
<uuid>9d37b878-a7cc-9f9a-b78f-49b3abad25a8</uuid>
</domain>
diff --git a/tests/domainsnapshotxml2xmlout/disk_snapshot.xml
b/tests/domainsnapshotxml2xmlout/disk_snapshot.xml
index 0a4b179..57aef16 100644
--- a/tests/domainsnapshotxml2xmlout/disk_snapshot.xml
+++ b/tests/domainsnapshotxml2xmlout/disk_snapshot.xml
@@ -6,6 +6,7 @@
<name>earlier_snap</name>
</parent>
<creationTime>1272917631</creationTime>
+ <memory snapshot='no'/>
<disks>
<disk name='hda' snapshot='no'/>
<disk name='hdb' snapshot='no'/>
diff --git a/tests/domainsnapshotxml2xmlout/external_vm.xml
b/tests/domainsnapshotxml2xmlout/external_vm.xml
new file mode 100644
index 0000000..8814bce
--- /dev/null
+++ b/tests/domainsnapshotxml2xmlout/external_vm.xml
@@ -0,0 +1,43 @@
+<domainsnapshot>
+ <name>my snap name</name>
+ <description>!@#$%^</description>
+ <state>running</state>
+ <parent>
+ <name>earlier_snap</name>
+ </parent>
+ <creationTime>1272917631</creationTime>
+ <memory snapshot='external' file='/dev/HostVG/GuestMemory'/>
+ <disks>
+ <disk name='hda' snapshot='no'/>
+ </disks>
+ <domain type='qemu'>
+ <name>QEMUGuest1</name>
+ <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+ <metadata>
+ <app1:foo xmlns:app1="http://foo.org/">fooish</app1:foo>
+ <app2:bar xmlns:app2="http://bar.com/"
maman="baz">barish</app2:bar>
+ </metadata>
+ <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' snapshot='no'>
+ <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'/>
+ <memballoon model='virtio'/>
+ </devices>
+ </domain>
+</domainsnapshot>
diff --git a/tests/domainsnapshotxml2xmlout/full_domain.xml
b/tests/domainsnapshotxml2xmlout/full_domain.xml
index 27cf41d..65d1469 100644
--- a/tests/domainsnapshotxml2xmlout/full_domain.xml
+++ b/tests/domainsnapshotxml2xmlout/full_domain.xml
@@ -6,6 +6,7 @@
<name>earlier_snap</name>
</parent>
<creationTime>1272917631</creationTime>
+ <memory snapshot='internal'/>
<domain type='qemu'>
<name>QEMUGuest1</name>
<uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
diff --git a/tests/domainsnapshotxml2xmlout/metadata.xml
b/tests/domainsnapshotxml2xmlout/metadata.xml
index 93c9f39..f961458 100644
--- a/tests/domainsnapshotxml2xmlout/metadata.xml
+++ b/tests/domainsnapshotxml2xmlout/metadata.xml
@@ -6,6 +6,7 @@
<name>earlier_snap</name>
</parent>
<creationTime>1272917631</creationTime>
+ <memory snapshot='internal'/>
<domain type='qemu'>
<name>QEMUGuest1</name>
<uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
diff --git a/tests/domainsnapshotxml2xmlout/noparent.xml
b/tests/domainsnapshotxml2xmlout/noparent.xml
index cbac0d8..0cbbb65 100644
--- a/tests/domainsnapshotxml2xmlout/noparent.xml
+++ b/tests/domainsnapshotxml2xmlout/noparent.xml
@@ -3,6 +3,7 @@
<description>!@#$%^</description>
<state>running</state>
<creationTime>1272917631</creationTime>
+ <memory snapshot='internal'/>
<domain>
<uuid>9d37b878-a7cc-9f9a-b78f-49b3abad25a8</uuid>
</domain>
diff --git a/tests/domainsnapshotxml2xmlout/noparent_nodescription.xml
b/tests/domainsnapshotxml2xmlout/noparent_nodescription.xml
index 0de202d..4eb4016 100644
--- a/tests/domainsnapshotxml2xmlout/noparent_nodescription.xml
+++ b/tests/domainsnapshotxml2xmlout/noparent_nodescription.xml
@@ -3,5 +3,6 @@
<description>!@#$%^</description>
<state>running</state>
<creationTime>1272917631</creationTime>
+ <memory snapshot='internal'/>
<active>1</active>
</domainsnapshot>
diff --git a/tests/domainsnapshotxml2xmlout/noparent_nodescription_noactive.xml
b/tests/domainsnapshotxml2xmlout/noparent_nodescription_noactive.xml
index 25b60f3..94d59a3 100644
--- a/tests/domainsnapshotxml2xmlout/noparent_nodescription_noactive.xml
+++ b/tests/domainsnapshotxml2xmlout/noparent_nodescription_noactive.xml
@@ -3,4 +3,5 @@
<description>!@#$%^</description>
<state>running</state>
<creationTime>1272917631</creationTime>
+ <memory snapshot='no'/>
</domainsnapshot>
diff --git a/tests/domainsnapshotxml2xmltest.c b/tests/domainsnapshotxml2xmltest.c
index e363c99..84278d6 100644
--- a/tests/domainsnapshotxml2xmltest.c
+++ b/tests/domainsnapshotxml2xmltest.c
@@ -110,6 +110,7 @@ mymain(void)
DO_TEST("noparent_nodescription", NULL, 1);
DO_TEST("noparent", "9d37b878-a7cc-9f9a-b78f-49b3abad25a8", 0);
DO_TEST("metadata", "c7a5fdbd-edaf-9455-926a-d65c16db1809", 0);
+ DO_TEST("external_vm", "c7a5fdbd-edaf-9455-926a-d65c16db1809",
0);
virCapabilitiesFree(driver.caps);
--
1.7.12.4