virstoragefile: Introduce virStoragePRDef

This is a definition that holds information on SCSI persistent reservation settings. The XML part looks like this: <reservations enabled='yes' managed='no'> <source type='unix' path='/path/to/qemu-pr-helper.sock' mode='client'/> </reservations> If @managed is set to 'yes' then the <source/> is not parsed. This design was agreed on here: https://www.redhat.com/archives/libvir-list/2017-November/msg01005.html Signed-off-by: Michal Privoznik <mprivozn@redhat.com> Reviewed-by: John Ferlan <jferlan@redhat.com>
2024-12-22 17:34:18 +03:00 · 2017-11-27 11:54:33 +01:00 · 2017-11-27 11:54:33 +01:00 · 687730540e
commit 687730540e
parent 4a3d6ed5ee
10 changed files with 316 additions and 31 deletions
--- a/docs/formatdomain.html.in
+++ b/docs/formatdomain.html.in
@ -2566,7 +2566,10 @@
  &lt;/disk&gt;
  &lt;disk type='block' device='lun'&gt;
    &lt;driver name='qemu' type='raw'/&gt;
-    &lt;source dev='/dev/sda'/&gt;
+    &lt;source dev='/dev/sda'&gt;
+      &lt;reservations enabled='yes' managed='no'&gt;
+        &lt;source type='unix' path='/path/to/qemu-pr-helper' mode='client'/&gt;
+      &lt;/reservations&gt;
    &lt;target dev='sda' bus='scsi'/&gt;
    &lt;address type='drive' controller='0' bus='0' target='3' unit='0'/&gt;
  &lt;/disk&gt;
@ -2929,6 +2932,26 @@
            <a href="formatstorageencryption.html">Storage Encryption</a>
            page for more information.
          </dd>
+          <dt><code>reservations</code></dt>
+          <dd><span class="since">Since libvirt 4.4.0</span>, the
+            <code>reservations</code> can be a sub-element of the
+            <code>source</code> element for storage sources (QEMU driver only).
+            If present (and enabled) it enables persistent reservations for SCSI
+            based disks. The element has one mandatory attribute
+            <code>enabled</code> with accepted values <code>yes</code> and
+            <code>no</code>. If the feature is enabled, then there's another
+            mandatory attribute <code>managed</code> (accepted values are the
+            same as for <code>enabled</code>) that enables or disables libvirt
+            spawning a helper process. When the PR is unmanaged, then hypervisor
+            acts as a client and path to server socket must be provided in child
+            element <code>source</code>, which currently accepts only the
+            following attributes: <code>type</code> with one value
+            <code>unix</code>, <code>path</code> with path the socket, and
+            finally <code>mode</code> which accepts one value
+            <code>client</code> and specifies the role of hypervisor.
+            It's recommended to allow libvirt manage the persistent
+            reservations.
+          </dd>
        </dl>

        <p>
--- a/docs/schemas/domaincommon.rng
+++ b/docs/schemas/domaincommon.rng
@ -1530,6 +1530,9 @@
        <optional>
          <ref name="encryption"/>
        </optional>
+        <optional>
+          <ref name="reservations"/>
+        </optional>
        <zeroOrMore>
          <ref name='devSeclabel'/>
        </zeroOrMore>
@ -2434,18 +2437,6 @@
      </attribute>
    </optional>
  </define>
-  <define name="reconnect">
-    <element name="reconnect">
-      <attribute name="enabled">
-        <ref name="virYesNo"/>
-      </attribute>
-      <optional>
-        <attribute name="timeout">
-          <ref name="unsignedInt"/>
-        </attribute>
-      </optional>
-    </element>
-  </define>

  <!--
      An interface description can either be of type bridge in which case
@ -2494,24 +2485,7 @@
            <value>vhostuser</value>
          </attribute>
          <interleave>
-            <element name="source">
-              <attribute name="type">
-                <value>unix</value>
-              </attribute>
-              <attribute name="path">
-                <ref name="absFilePath"/>
-              </attribute>
-              <attribute name="mode">
-                <choice>
-                  <value>server</value>
-                  <value>client</value>
-                </choice>
-              </attribute>
-              <optional>
-                 <ref name="reconnect"/>
-              </optional>
-              <empty/>
-            </element>
+            <ref name="unixSocketSource"/>
            <ref name="interface-options"/>
          </interleave>
        </group>
--- a/docs/schemas/storagecommon.rng
+++ b/docs/schemas/storagecommon.rng
@ -39,6 +39,56 @@
    </element>
  </define>

+  <define name="reconnect">
+    <element name="reconnect">
+      <attribute name="enabled">
+        <ref name="virYesNo"/>
+      </attribute>
+      <optional>
+        <attribute name="timeout">
+          <ref name="unsignedInt"/>
+        </attribute>
+      </optional>
+    </element>
+  </define>
+
+  <define name='unixSocketSource'>
+    <element name="source">
+      <attribute name="type">
+        <value>unix</value>
+      </attribute>
+      <attribute name="path">
+        <ref name="absFilePath"/>
+      </attribute>
+      <attribute name="mode">
+        <choice>
+          <value>server</value>
+          <value>client</value>
+        </choice>
+      </attribute>
+      <optional>
+         <ref name="reconnect"/>
+      </optional>
+      <empty/>
+    </element>
+  </define>
+
+  <define name='reservations'>
+    <element name='reservations'>
+      <attribute name='enabled'>
+        <ref name='virYesNo'/>
+      </attribute>
+      <optional>
+        <attribute name='managed'>
+          <ref name='virYesNo'/>
+        </attribute>
+      </optional>
+      <optional>
+        <ref name='unixSocketSource'/>
+      </optional>
+    </element>
+  </define>
+
  <define name='secret'>
    <element name='secret'>
      <attribute name='type'>
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@ -5206,6 +5206,13 @@ virDomainDiskDefValidate(const virDomainDiskDef *disk)
        }
    }

+    if (disk->src->pr &&
+        disk->device != VIR_DOMAIN_DISK_DEVICE_LUN) {
+        virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                       _("<reservations/> allowed only for lun devices"));
+        return -1;
+    }
+
    /* Reject disks with a bus type that is not compatible with the
     * given address type. The function considers only buses that are
     * handled in common code. For other bus types it's not possible
@ -8632,6 +8639,31 @@ virDomainDiskSourcePrivateDataParse(xmlNodePtr node,
 }


+static int
+virDomainDiskSourcePRParse(xmlNodePtr node,
+                           xmlXPathContextPtr ctxt,
+                           virStoragePRDefPtr *pr)
+{
+    xmlNodePtr saveNode = ctxt->node;
+    int ret = -1;
+
+    ctxt->node = node;
+
+    if (!(ctxt->node = virXPathNode("./reservations", ctxt))) {
+        ret = 0;
+        goto cleanup;
+    }
+
+    if (!(*pr = virStoragePRDefParseXML(ctxt)))
+        goto cleanup;
+
+    ret = 0;
+ cleanup:
+    ctxt->node = saveNode;
+    return ret;
+}
+
+
 static int
 virDomainStorageSourceParse(xmlNodePtr node,
                            xmlXPathContextPtr ctxt,
@ -8678,6 +8710,9 @@ virDomainStorageSourceParse(xmlNodePtr node,
        !(src->encryption = virStorageEncryptionParseNode(tmp, ctxt)))
        goto cleanup;

+    if (virDomainDiskSourcePRParse(node, ctxt, &src->pr) < 0)
+        goto cleanup;
+
    if (virSecurityDeviceLabelDefParseXML(&src->seclabels, &src->nseclabels,
                                          ctxt, flags) < 0)
        goto cleanup;
@ -22953,6 +22988,9 @@ virDomainStorageSourceFormat(virBufferPtr attrBuf,
        virStorageEncryptionFormat(childBuf, src->encryption) < 0)
        return -1;

+    if (src->pr)
+        virStoragePRDefFormat(childBuf, src->pr);
+
    return 0;
 }

--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@ -2801,6 +2801,9 @@ virStorageNetHostDefFree;
 virStorageNetHostTransportTypeFromString;
 virStorageNetHostTransportTypeToString;
 virStorageNetProtocolTypeToString;
+virStoragePRDefFormat;
+virStoragePRDefFree;
+virStoragePRDefParseXML;
 virStorageSourceBackingStoreClear;
 virStorageSourceClear;
 virStorageSourceCopy;
--- a/src/util/virstoragefile.c
+++ b/src/util/virstoragefile.c
@ -1892,6 +1892,136 @@ virStorageAuthDefFormat(virBufferPtr buf,
 }


+void
+virStoragePRDefFree(virStoragePRDefPtr prd)
+{
+    if (!prd)
+        return;
+
+    VIR_FREE(prd->path);
+    VIR_FREE(prd);
+}
+
+
+virStoragePRDefPtr
+virStoragePRDefParseXML(xmlXPathContextPtr ctxt)
+{
+    virStoragePRDefPtr prd, ret = NULL;
+    char *enabled = NULL;
+    char *managed = NULL;
+    char *type = NULL;
+    char *path = NULL;
+    char *mode = NULL;
+
+    if (VIR_ALLOC(prd) < 0)
+        return NULL;
+
+    if (!(enabled = virXPathString("string(./@enabled)", ctxt))) {
+        virReportError(VIR_ERR_XML_ERROR, "%s",
+                       _("missing @enabled attribute for <reservations/>"));
+        goto cleanup;
+    }
+
+    if ((prd->enabled = virTristateBoolTypeFromString(enabled)) <= 0) {
+        virReportError(VIR_ERR_XML_ERROR,
+                       _("invalid value for 'enabled': %s"), enabled);
+        goto cleanup;
+    }
+
+    if (prd->enabled == VIR_TRISTATE_BOOL_YES) {
+        if (!(managed = virXPathString("string(./@managed)", ctxt))) {
+            virReportError(VIR_ERR_XML_ERROR, "%s",
+                           _("missing @managed attribute for <reservations/>"));
+            goto cleanup;
+        }
+
+        if ((prd->managed = virTristateBoolTypeFromString(managed)) <= 0) {
+            virReportError(VIR_ERR_XML_ERROR,
+                           _("invalid value for 'managed': %s"), managed);
+            goto cleanup;
+        }
+
+        if (prd->managed == VIR_TRISTATE_BOOL_NO) {
+            type = virXPathString("string(./source[1]/@type)", ctxt);
+            path = virXPathString("string(./source[1]/@path)", ctxt);
+            mode = virXPathString("string(./source[1]/@mode)", ctxt);
+
+            if (!type) {
+                virReportError(VIR_ERR_XML_ERROR, "%s",
+                               _("missing connection type for <reservations/>"));
+                goto cleanup;
+            }
+
+            if (!path) {
+                virReportError(VIR_ERR_XML_ERROR, "%s",
+                               _("missing path for <reservations/>"));
+                goto cleanup;
+            }
+
+            if (!mode) {
+                virReportError(VIR_ERR_XML_ERROR, "%s",
+                               _("missing connection mode for <reservations/>"));
+                goto cleanup;
+            }
+
+            if (STRNEQ(type, "unix")) {
+                virReportError(VIR_ERR_XML_ERROR,
+                               _("unsupported connection type for <reservations/>: %s"),
+                               type);
+                goto cleanup;
+            }
+
+            if (STRNEQ(mode, "client")) {
+                virReportError(VIR_ERR_XML_ERROR,
+                               _("unsupported connection mode for <reservations/>: %s"),
+                               mode);
+                goto cleanup;
+            }
+
+            VIR_STEAL_PTR(prd->path, path);
+        }
+    }
+
+    ret = prd;
+    prd = NULL;
+
+ cleanup:
+    VIR_FREE(mode);
+    VIR_FREE(path);
+    VIR_FREE(type);
+    VIR_FREE(managed);
+    VIR_FREE(enabled);
+    virStoragePRDefFree(prd);
+    return ret;
+}
+
+
+void
+virStoragePRDefFormat(virBufferPtr buf,
+                      virStoragePRDefPtr prd)
+{
+    virBufferAsprintf(buf, "<reservations enabled='%s'",
+                      virTristateBoolTypeToString(prd->enabled));
+    if (prd->enabled == VIR_TRISTATE_BOOL_YES) {
+        virBufferAsprintf(buf, " managed='%s'",
+                          virTristateBoolTypeToString(prd->managed));
+        if (prd->managed == VIR_TRISTATE_BOOL_NO) {
+            virBufferAddLit(buf, ">\n");
+            virBufferAdjustIndent(buf, 2);
+            virBufferAddLit(buf, "<source type='unix'");
+            virBufferEscapeString(buf, " path='%s'", prd->path);
+            virBufferAddLit(buf, " mode='client'/>\n");
+            virBufferAdjustIndent(buf, -2);
+            virBufferAddLit(buf, "</reservations>\n");
+        } else {
+            virBufferAddLit(buf, "/>\n");
+        }
+    } else {
+        virBufferAddLit(buf, "/>\n");
+    }
+}
+
+
 virSecurityDeviceLabelDefPtr
 virStorageSourceGetSecurityLabelDef(virStorageSourcePtr src,
                                    const char *model)
@ -2268,6 +2398,7 @@ virStorageSourceClear(virStorageSourcePtr def)
    virBitmapFree(def->features);
    VIR_FREE(def->compat);
    virStorageEncryptionFree(def->encryption);
+    virStoragePRDefFree(def->pr);
    virStorageSourceSeclabelsClear(def);
    virStoragePermsFree(def->perms);
    VIR_FREE(def->timestamps);
--- a/src/util/virstoragefile.h
+++ b/src/util/virstoragefile.h
@ -216,6 +216,14 @@ struct _virStorageAuthDef {
    virSecretLookupTypeDef seclookupdef;
 };

+typedef struct _virStoragePRDef virStoragePRDef;
+typedef virStoragePRDef *virStoragePRDefPtr;
+struct _virStoragePRDef {
+    int enabled; /* enum virTristateBool */
+    int managed; /* enum virTristateBool */
+    char *path;
+};
+
 typedef struct _virStorageDriverData virStorageDriverData;
 typedef virStorageDriverData *virStorageDriverDataPtr;

@ -243,6 +251,7 @@ struct _virStorageSource {
    bool authInherited;
    virStorageEncryptionPtr encryption;
    bool encryptionInherited;
+    virStoragePRDefPtr pr;

    virObjectPtr privateData;

@ -382,6 +391,11 @@ virStorageAuthDefPtr virStorageAuthDefParse(xmlNodePtr node,
                                            xmlXPathContextPtr ctxt);
 void virStorageAuthDefFormat(virBufferPtr buf, virStorageAuthDefPtr authdef);

+void virStoragePRDefFree(virStoragePRDefPtr prd);
+virStoragePRDefPtr virStoragePRDefParseXML(xmlXPathContextPtr ctxt);
+void virStoragePRDefFormat(virBufferPtr buf,
+                           virStoragePRDefPtr prd);
+
 virSecurityDeviceLabelDefPtr
 virStorageSourceGetSecurityLabelDef(virStorageSourcePtr src,
                                    const char *model);
--- a/tests/qemuxml2argvdata/disk-virtio-scsi-reservations.xml
+++ b/tests/qemuxml2argvdata/disk-virtio-scsi-reservations.xml
@ -0,0 +1,49 @@
+<domain type='qemu'>
+  <name>QEMUGuest1</name>
+  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+  <memory unit='KiB'>219136</memory>
+  <currentMemory unit='KiB'>219136</currentMemory>
+  <vcpu placement='static'>8</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-system-i686</emulator>
+    <disk type='block' device='lun'>
+      <driver name='qemu' type='raw'/>
+      <source dev='/dev/HostVG/QEMUGuest1'>
+        <reservations enabled='yes' managed='yes'/>
+      </source>
+      <target dev='sda' bus='scsi'/>
+      <address type='drive' controller='0' bus='0' target='0' unit='0'/>
+    </disk>
+    <disk type='block' device='lun'>
+      <driver name='qemu' type='raw'/>
+      <source dev='/dev/HostVG/QEMUGuest2'>
+        <reservations enabled='yes' managed='no'>
+          <source type='unix' path='/path/to/qemu-pr-helper.sock' mode='client'/>
+        </reservations>
+      </source>
+      <target dev='sdb' bus='scsi'/>
+      <address type='drive' controller='0' bus='0' target='0' unit='1'/>
+    </disk>
+    <controller type='usb' index='0'>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x2'/>
+    </controller>
+    <controller type='scsi' index='0' model='virtio-scsi'>
+      <driver queues='8'/>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>
+    </controller>
+    <controller type='pci' index='0' model='pci-root'/>
+    <input type='mouse' bus='ps2'/>
+    <input type='keyboard' bus='ps2'/>
+    <memballoon model='virtio'>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/>
+    </memballoon>
+  </devices>
+</domain>
--- a/tests/qemuxml2xmloutdata/disk-virtio-scsi-reservations.xml
+++ b/tests/qemuxml2xmloutdata/disk-virtio-scsi-reservations.xml
@ -0,0 +1 @@
+../qemuxml2argvdata/disk-virtio-scsi-reservations.xml
--- a/tests/qemuxml2xmltest.c
+++ b/tests/qemuxml2xmltest.c
@ -387,6 +387,8 @@ mymain(void)
            QEMU_CAPS_VIRTIO_SCSI);
    DO_TEST("disk-virtio-scsi-num_queues",
            QEMU_CAPS_VIRTIO_SCSI);
+    DO_TEST("disk-virtio-scsi-reservations",
+            QEMU_CAPS_VIRTIO_SCSI);
    DO_TEST("disk-virtio-scsi-cmd_per_lun",
            QEMU_CAPS_VIRTIO_SCSI);
    DO_TEST("disk-virtio-scsi-max_sectors",
				`@ -0,0 +1 @@`
				`../qemuxml2argvdata/disk-virtio-scsi-reservations.xml`