[libvirt] [PATCH v2 2/5] link-state: conf: Add element to XML for controling link state

Peter Krempa pkrempa at redhat.com
Tue Aug 30 14:38:55 UTC 2011


A new element is introduced to XML that allows to control
state of virtual network interfaces in hypervisors.

Live modification of the link state allows networking tools
propagate topology changes to guest OS or testing of
scenarios in complex (virtual) networks.

This patch adds elements to XML grammars and parsing and generating
code.

 docs/formatdomain.html.in  - Documentation of new element
 docs/schemas/domain.rng    - Grammar for the new element
 src/conf/domain_conf.c     - Parsing and generating code
 src/conf/domain_conf.h     - Enum of available link states
---
 docs/formatdomain.html.in |   21 +++++++++++++++++++++
 docs/schemas/domain.rng   |   11 +++++++++++
 src/conf/domain_conf.c    |   24 ++++++++++++++++++++++++
 src/conf/domain_conf.h    |   11 +++++++++++
 4 files changed, 67 insertions(+), 0 deletions(-)

diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in
index f46771d..47cf0e6 100644
--- a/docs/formatdomain.html.in
+++ b/docs/formatdomain.html.in
@@ -2024,6 +2024,27 @@ qemu-kvm -net nic,model=? /dev/null
       <span class="since">Since 0.9.4</span>
     </p>

+    <h5><a name="elementLink">Modyfing virtual link state</a></h5>
+<pre>
+  ...
+  <devices>
+    <interface type='network'>
+      <source network='default'/>
+      <target dev='vnet0'/>
+      <b><link state='down'/></b>
+    </interface>
+  <devices>
+  ...</pre>
+
+    <p>
+      This element provides means of setting state of the virtual network link.
+      Possible values for attribute <code>state</code> are <code>up</code> and
+      <code>down</code>. If <code>down</code> is specified as the value, the interface
+      behaves as if it had the network cable disconnected. Default behavior if this
+      element is unspecified is to have the link state <code>up</code>.
+      <span class="since">Since 0.9.5</span>
+    </p>
+
     <h4><a name="elementsInput">Input devices</a></h4>

     <p>
diff --git a/docs/schemas/domain.rng b/docs/schemas/domain.rng
index dd8c41a..d2b73ac 100644
--- a/docs/schemas/domain.rng
+++ b/docs/schemas/domain.rng
@@ -1206,6 +1206,17 @@
       <optional>
         <ref name="bandwidth"/>
       </optional>
+      <optional>
+        <element name="link">
+          <attribute name="state">
+            <choice>
+              <value>up</value>
+              <value>down</value>
+            </choice>
+          </attribute>
+          <empty/>
+        </element>
+      </optional>
     </interleave>
   </define>
   <!--
diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index 44212cf..f480f37 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -235,6 +235,11 @@ VIR_ENUM_IMPL(virDomainNetVirtioTxMode, VIR_DOMAIN_NET_VIRTIO_TX_MODE_LAST,
               "iothread",
               "timer")

+VIR_ENUM_IMPL(virDomainNetInterfaceLinkState, VIR_DOMAIN_NET_INTERFACE_LINK_STATE_LAST,
+              "default",
+              "up",
+              "down")
+
 VIR_ENUM_IMPL(virDomainChrChannelTarget,
               VIR_DOMAIN_CHR_CHANNEL_TARGET_TYPE_LAST,
               "guestfwd",
@@ -2774,6 +2779,7 @@ virDomainNetDefParseXML(virCapsPtr caps,
     char *internal = NULL;
     char *devaddr = NULL;
     char *mode = NULL;
+    char *linkstate = NULL;
     virNWFilterHashTablePtr filterparams = NULL;
     virVirtualPortProfileParamsPtr virtPort = NULL;
     virDomainActualNetDefPtr actual = NULL;
@@ -2850,6 +2856,9 @@ virDomainNetDefParseXML(virCapsPtr caps,
                     /* An auto-generated target name, blank it out */
                     VIR_FREE(ifname);
                 }
+            } else if ((linkstate == NULL) &&
+                       xmlStrEqual(cur->name, BAD_CAST "link")) {
+                linkstate = virXMLPropString(cur, "state");
             } else if ((script == NULL) &&
                        (def->type == VIR_DOMAIN_NET_TYPE_ETHERNET ||
                         def->type == VIR_DOMAIN_NET_TYPE_BRIDGE) &&
@@ -3114,6 +3123,16 @@ virDomainNetDefParseXML(virCapsPtr caps,
         }
     }

+    def->linkstate = VIR_DOMAIN_NET_INTERFACE_LINK_STATE_DEFAULT;
+    if (linkstate != NULL) {
+        if ((def->linkstate = virDomainNetInterfaceLinkStateTypeFromString(linkstate)) <= 0) {
+            virDomainReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+                                 _("unknown interface link state '%s'"),
+                                 linkstate);
+            goto error;
+        }
+    }
+
     if (filter != NULL) {
         switch (def->type) {
         case VIR_DOMAIN_NET_TYPE_ETHERNET:
@@ -3161,6 +3180,7 @@ cleanup:
     VIR_FREE(internal);
     VIR_FREE(devaddr);
     VIR_FREE(mode);
+    VIR_FREE(linkstate);
     virNWFilterHashTableFree(filterparams);

     return def;
@@ -9057,6 +9077,10 @@ virDomainNetDefFormat(virBufferPtr buf,
         virBufferAddLit(buf,   "      </tune>\n");
     }

+    if (def->linkstate)
+        virBufferAsprintf(buf, "      <link state='%s'/>\n",
+                          virDomainNetInterfaceLinkStateTypeToString(def->linkstate));
+
     if (virBandwidthDefFormat(buf, def->bandwidth, "      ") < 0)
         return -1;

diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h
index 8382d28..6e0c8fe 100644
--- a/src/conf/domain_conf.h
+++ b/src/conf/domain_conf.h
@@ -352,6 +352,15 @@ enum virDomainNetVirtioTxModeType {
     VIR_DOMAIN_NET_VIRTIO_TX_MODE_LAST,
 };

+/* link interface states */
+enum virDomainNetInterfaceLinkState {
+        VIR_DOMAIN_NET_INTERFACE_LINK_STATE_DEFAULT = 0, /* Default link state (up) */
+        VIR_DOMAIN_NET_INTERFACE_LINK_STATE_UP,          /* Link is up. ("cable" connected) */
+        VIR_DOMAIN_NET_INTERFACE_LINK_STATE_DOWN ,       /* Link is down. ("cable" disconnected) */
+
+        VIR_DOMAIN_NET_INTERFACE_LINK_STATE_LAST
+};
+
 /* Config that was actually used to bring up interface, after
  * resolving network reference. This is private data, only used within
  * libvirt, but still must maintain backward compatibility, because
@@ -437,6 +446,7 @@ struct _virDomainNetDef {
     char *filter;
     virNWFilterHashTablePtr filterparams;
     virBandwidthPtr bandwidth;
+    int linkstate;
 };

 /* Used for prefix of ifname of any network name generated dynamically
@@ -1681,6 +1691,7 @@ VIR_ENUM_DECL(virDomainFSAccessMode)
 VIR_ENUM_DECL(virDomainNet)
 VIR_ENUM_DECL(virDomainNetBackend)
 VIR_ENUM_DECL(virDomainNetVirtioTxMode)
+VIR_ENUM_DECL(virDomainNetInterfaceLinkState)
 VIR_ENUM_DECL(virDomainChrDevice)
 VIR_ENUM_DECL(virDomainChrChannelTarget)
 VIR_ENUM_DECL(virDomainChrConsoleTarget)
-- 
1.7.3.4




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