conf: Add VM Generation ID parse/format support

The VM Generation ID is a mechanism to provide a unique 128-bit,
cryptographically random, and integer value identifier known as
the GUID (Globally Unique Identifier) to the guest OS. The value
is used to help notify the guest operating system when the virtual
machine is executed with a different configuration.

This patch adds support for a new "genid" XML element similar to
the "uuid" element. The "genid" element can have two forms "<genid/>"
or "<genid>$GUID</genid>". If the $GUID is not provided, libvirt
will generate one and save it in the XML.

Since adding support for a generated GUID (or UUID like) value to
be displayed modifying the xml2xml test to include virrandommock.so
is necessary since it will generate a "known" value.

Signed-off-by: John Ferlan <jferlan@redhat.com>
ACKed-by: Michal Privoznik <mprivozn@redhat.com>

diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in
index 665d0f25293e440868cc87a18683c7af0b671bd4..9f6e8ee7327cb5216f547c418a7bda2a6bb3976d 100644 (file)
--- a/docs/formatdomain.html.in
+++ b/docs/formatdomain.html.in
@@ -34,6 +34,7 @@
 <domain type='kvm' id='1'>
   <name>MyGuest</name>
   <uuid>4dea22b3-1d52-d8f3-2516-782e98ab3fa0</uuid>
+  <genid>43dc0cf8-809b-4adb-9bea-a9abb5f3d90e</genid>
   <title>A short description - title - of the domain</title>
   <description>Some human readable description</description>
   <metadata>
@@ -61,6 +62,32 @@
         specification. <span class="since">Since 0.0.1, sysinfo
         since 0.8.7</span></dd>
 
+      <dt><code>genid</code></dt>
+      <dd><span class="since">Since 4.4.0</span>, the <code>genid</code>
+        element can be used to add a Virtual Machine Generation ID which
+        exposes a 128-bit, cryptographically random, integer value identifier,
+        referred to as a Globally Unique Identifier (GUID) using the same
+        format as the <code>uuid</code>. The value is used to help notify
+        the guest operating system when the virtual machine is re-executing
+        something that has already executed before, such as:
+
+        <ul>
+          <li>VM starts executing a snapshot</li>
+          <li>VM is recovered from backup</li>
+          <li>VM is failover in a disaster recovery environment</li>
+          <li>VM is imported, copied, or cloned</li>
+        </ul>
+
+        The guest operating system notices the change and is then able to
+        react as appropriate by marking its copies of distributed databases
+        as dirty, re-initializing its random number generator, etc.
+
+        <p>
+        The libvirt XML parser will accept both a provided GUID value
+        or just &lt;genid/&gt; in which case a GUID will be generated
+        and saved in the XML. For the transitions such as above, libvirt
+        will change the GUID before re-executing.</p></dd>
+
       <dt><code>title</code></dt>
       <dd>The optional element <code>title</code> provides space for a
         short description of the domain. The title should not contain

diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng
index f16e157397d4825e1591e18fce91bd5226d64b4f..2cb9bfea98bea10eb66e75fe50a5560f9e9b382c 100644 (file)
--- a/docs/schemas/domaincommon.rng
+++ b/docs/schemas/domaincommon.rng
@@ -502,6 +502,14 @@
           <ref name="UUID"/>
         </element>
       </optional>
+      <optional>
+        <element name="genid">
+          <choice>
+            <ref name="UUID"/>
+            <empty/>
+          </choice>
+        </element>
+      </optional>
     </interleave>
   </define>
   <define name="idmap">

diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index 2253098090295f014f49301b12aa3d689d13364d..d6ac47c62935c9d41fae19422932cc7d5032c2e9 100644 (file)
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -18920,6 +18920,34 @@ virDomainDefParseXML(xmlDocPtr xml,
         VIR_FREE(tmp);
     }
 
+    /* Extract domain genid - a genid can either be provided or generated */
+    if ((n = virXPathNodeSet("./genid", ctxt, &nodes)) < 0)
+        goto error;
+
+    if (n > 0) {
+        if (n != 1) {
+            virReportError(VIR_ERR_XML_ERROR, "%s",
+                           _("element 'genid' can only appear once"));
+            goto error;
+        }
+        def->genidRequested = true;
+        if (!(tmp = virXPathString("string(./genid)", ctxt))) {
+            if (virUUIDGenerate(def->genid) < 0) {
+                virReportError(VIR_ERR_INTERNAL_ERROR,
+                               "%s", _("Failed to generate genid"));
+                goto error;
+            }
+            def->genidGenerated = true;
+        } else {
+            if (virUUIDParse(tmp, def->genid) < 0) {
+                virReportError(VIR_ERR_INTERNAL_ERROR,
+                               "%s", _("malformed genid element"));
+                goto error;
+            }
+        }
+    }
+    VIR_FREE(nodes);
+
     /* Extract short description of domain (title) */
     def->title = virXPathString("string(./title[1])", ctxt);
     if (def->title && strchr(def->title, '\n')) {
@@ -22034,6 +22062,25 @@ virDomainDefCheckABIStabilityFlags(virDomainDefPtr src,
         goto error;
     }
 
+    if (src->genidRequested != dst->genidRequested) {
+        virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                       _("Target domain requested genid does not match source"));
+        goto error;
+    }
+
+    if (src->genidRequested &&
+        memcmp(src->genid, dst->genid, VIR_UUID_BUFLEN) != 0) {
+        char guidsrc[VIR_UUID_STRING_BUFLEN];
+        char guiddst[VIR_UUID_STRING_BUFLEN];
+
+        virUUIDFormat(src->genid, guidsrc);
+        virUUIDFormat(dst->genid, guiddst);
+        virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+                       _("Target domain genid %s does not match source %s"),
+                       guiddst, guidsrc);
+        goto error;
+    }
+
     /* Not strictly ABI related, but we want to make sure domains
      * don't get silently re-named through the backdoor when passing
      * custom XML into various APIs, since this would create havoc
@@ -26752,6 +26799,13 @@ virDomainDefFormatInternal(virDomainDefPtr def,
     virUUIDFormat(uuid, uuidstr);
     virBufferAsprintf(buf, "<uuid>%s</uuid>\n", uuidstr);
 
+    if (def->genidRequested) {
+        char genidstr[VIR_UUID_STRING_BUFLEN];
+
+        virUUIDFormat(def->genid, genidstr);
+        virBufferAsprintf(buf, "<genid>%s</genid>\n", genidstr);
+    }
+
     virBufferEscapeString(buf, "<title>%s</title>\n", def->title);
 
     virBufferEscapeString(buf, "<description>%s</description>\n",

diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h
index 37356df42d715a81c197f927affe59fbb6cea46d..b7e52a1e03b68efbd93bc4f2fbf94d4a8dbff28e 100644 (file)
--- a/src/conf/domain_conf.h
+++ b/src/conf/domain_conf.h
@@ -2328,6 +2328,11 @@ struct _virDomainDef {
     virDomainVirtType virtType;
     int id;
     unsigned char uuid[VIR_UUID_BUFLEN];
+
+    unsigned char genid[VIR_UUID_BUFLEN];
+    bool genidRequested;
+    bool genidGenerated;
+
     char *name;
     char *title;
     char *description;

diff --git a/tests/qemuxml2argvdata/genid-auto.xml b/tests/qemuxml2argvdata/genid-auto.xml
new file mode 100644 (file)
index 0000000..96ad9dd
--- /dev/null
+++ b/tests/qemuxml2argvdata/genid-auto.xml
@@ -0,0 +1,32 @@
+<domain type='qemu' id='1'>
+  <name>QEMUGuest1</name>
+  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+  <genid/>
+  <memory unit='KiB'>219136</memory>
+  <currentMemory unit='KiB'>219136</currentMemory>
+  <vcpu placement='static'>1</vcpu>
+  <os>
+    <type arch='x86_64' machine='pc'>hvm</type>
+    <boot dev='hd'/>
+  </os>
+  <features>
+    <acpi/>
+  </features>
+  <clock offset='utc'/>
+  <on_poweroff>destroy</on_poweroff>
+  <on_reboot>restart</on_reboot>
+  <on_crash>destroy</on_crash>
+  <devices>
+    <emulator>/usr/bin/qemu-system-x86_64</emulator>
+    <controller type='usb' index='0'>
+      <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'/>
+    <memballoon model='none'/>
+  </devices>
+</domain>

diff --git a/tests/qemuxml2argvdata/genid.xml b/tests/qemuxml2argvdata/genid.xml
new file mode 100644 (file)
index 0000000..fc41f2d
--- /dev/null
+++ b/tests/qemuxml2argvdata/genid.xml
@@ -0,0 +1,32 @@
+<domain type='qemu' id='1'>
+  <name>QEMUGuest1</name>
+  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+  <genid>e9392370-2917-565e-692b-d057f46512d6</genid>
+  <memory unit='KiB'>219136</memory>
+  <currentMemory unit='KiB'>219136</currentMemory>
+  <vcpu placement='static'>1</vcpu>
+  <os>
+    <type arch='x86_64' machine='pc'>hvm</type>
+    <boot dev='hd'/>
+  </os>
+  <features>
+    <acpi/>
+  </features>
+  <clock offset='utc'/>
+  <on_poweroff>destroy</on_poweroff>
+  <on_reboot>restart</on_reboot>
+  <on_crash>destroy</on_crash>
+  <devices>
+    <emulator>/usr/bin/qemu-system-x86_64</emulator>
+    <controller type='usb' index='0'>
+      <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'/>
+    <memballoon model='none'/>
+  </devices>
+</domain>

diff --git a/tests/qemuxml2xmloutdata/genid-active.xml b/tests/qemuxml2xmloutdata/genid-active.xml
new file mode 100644 (file)
index 0000000..fc41f2d
--- /dev/null
+++ b/tests/qemuxml2xmloutdata/genid-active.xml
@@ -0,0 +1,32 @@
+<domain type='qemu' id='1'>
+  <name>QEMUGuest1</name>
+  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+  <genid>e9392370-2917-565e-692b-d057f46512d6</genid>
+  <memory unit='KiB'>219136</memory>
+  <currentMemory unit='KiB'>219136</currentMemory>
+  <vcpu placement='static'>1</vcpu>
+  <os>
+    <type arch='x86_64' machine='pc'>hvm</type>
+    <boot dev='hd'/>
+  </os>
+  <features>
+    <acpi/>
+  </features>
+  <clock offset='utc'/>
+  <on_poweroff>destroy</on_poweroff>
+  <on_reboot>restart</on_reboot>
+  <on_crash>destroy</on_crash>
+  <devices>
+    <emulator>/usr/bin/qemu-system-x86_64</emulator>
+    <controller type='usb' index='0'>
+      <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'/>
+    <memballoon model='none'/>
+  </devices>
+</domain>

diff --git a/tests/qemuxml2xmloutdata/genid-auto-active.xml b/tests/qemuxml2xmloutdata/genid-auto-active.xml
new file mode 100644 (file)
index 0000000..aeca0d7
--- /dev/null
+++ b/tests/qemuxml2xmloutdata/genid-auto-active.xml
@@ -0,0 +1,32 @@
+<domain type='qemu' id='1'>
+  <name>QEMUGuest1</name>
+  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+  <genid>00010203-0405-4607-8809-0a0b0c0d0e0f</genid>
+  <memory unit='KiB'>219136</memory>
+  <currentMemory unit='KiB'>219136</currentMemory>
+  <vcpu placement='static'>1</vcpu>
+  <os>
+    <type arch='x86_64' machine='pc'>hvm</type>
+    <boot dev='hd'/>
+  </os>
+  <features>
+    <acpi/>
+  </features>
+  <clock offset='utc'/>
+  <on_poweroff>destroy</on_poweroff>
+  <on_reboot>restart</on_reboot>
+  <on_crash>destroy</on_crash>
+  <devices>
+    <emulator>/usr/bin/qemu-system-x86_64</emulator>
+    <controller type='usb' index='0'>
+      <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'/>
+    <memballoon model='none'/>
+  </devices>
+</domain>

diff --git a/tests/qemuxml2xmloutdata/genid-auto-inactive.xml b/tests/qemuxml2xmloutdata/genid-auto-inactive.xml
new file mode 100644 (file)
index 0000000..a7b711d
--- /dev/null
+++ b/tests/qemuxml2xmloutdata/genid-auto-inactive.xml
@@ -0,0 +1,32 @@
+<domain type='qemu'>
+  <name>QEMUGuest1</name>
+  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+  <genid>00010203-0405-4607-8809-0a0b0c0d0e0f</genid>
+  <memory unit='KiB'>219136</memory>
+  <currentMemory unit='KiB'>219136</currentMemory>
+  <vcpu placement='static'>1</vcpu>
+  <os>
+    <type arch='x86_64' machine='pc'>hvm</type>
+    <boot dev='hd'/>
+  </os>
+  <features>
+    <acpi/>
+  </features>
+  <clock offset='utc'/>
+  <on_poweroff>destroy</on_poweroff>
+  <on_reboot>restart</on_reboot>
+  <on_crash>destroy</on_crash>
+  <devices>
+    <emulator>/usr/bin/qemu-system-x86_64</emulator>
+    <controller type='usb' index='0'>
+      <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'/>
+    <memballoon model='none'/>
+  </devices>
+</domain>

diff --git a/tests/qemuxml2xmloutdata/genid-inactive.xml b/tests/qemuxml2xmloutdata/genid-inactive.xml
new file mode 100644 (file)
index 0000000..8bd526a
--- /dev/null
+++ b/tests/qemuxml2xmloutdata/genid-inactive.xml
@@ -0,0 +1,32 @@
+<domain type='qemu'>
+  <name>QEMUGuest1</name>
+  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+  <genid>e9392370-2917-565e-692b-d057f46512d6</genid>
+  <memory unit='KiB'>219136</memory>
+  <currentMemory unit='KiB'>219136</currentMemory>
+  <vcpu placement='static'>1</vcpu>
+  <os>
+    <type arch='x86_64' machine='pc'>hvm</type>
+    <boot dev='hd'/>
+  </os>
+  <features>
+    <acpi/>
+  </features>
+  <clock offset='utc'/>
+  <on_poweroff>destroy</on_poweroff>
+  <on_reboot>restart</on_reboot>
+  <on_crash>destroy</on_crash>
+  <devices>
+    <emulator>/usr/bin/qemu-system-x86_64</emulator>
+    <controller type='usb' index='0'>
+      <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'/>
+    <memballoon model='none'/>
+  </devices>
+</domain>

diff --git a/tests/qemuxml2xmltest.c b/tests/qemuxml2xmltest.c
index e31d8212fef11e0bc2b36683826dda364ec82a4c..bd7433dce455375100c2c485f14db8389c56c10b 100644 (file)
--- a/tests/qemuxml2xmltest.c
+++ b/tests/qemuxml2xmltest.c
@@ -276,6 +276,8 @@ mymain(void)
     setenv("PATH", "/bin", 1);
 
     DO_TEST("minimal", NONE);
+    DO_TEST("genid", NONE);
+    DO_TEST("genid-auto", NONE);
     DO_TEST("machine-core-on", NONE);
     DO_TEST("machine-core-off", NONE);
     DO_TEST("machine-loadparm-multiple-disks-nets-s390", NONE);
@@ -1220,7 +1222,8 @@ mymain(void)
 }
 
 VIR_TEST_MAIN_PRELOAD(mymain,
-                      abs_builddir "/.libs/virpcimock.so")
+                      abs_builddir "/.libs/virpcimock.so",
+                      abs_builddir "/.libs/virrandommock.so")
 
 #else