[libvirt PATCH 1/6] conf: add support for <acpi index='NNN'/> for PCI devices

Daniel P. Berrangé berrange at redhat.com
Tue Apr 6 15:31:32 UTC 2021


PCI devices can be associated with a unique integer index that is
exposed via ACPI. In Linux OS with systemd, this value is used for
provide a NIC device naming scheme that is stable across changes
in PCI slot configuration.

Signed-off-by: Daniel P. Berrangé <berrange at redhat.com>
---
 docs/formatdomain.rst         |  6 +++
 docs/schemas/domaincommon.rng | 73 +++++++++++++++++++++++++++++++++++
 src/conf/device_conf.h        |  3 ++
 src/conf/domain_conf.c        | 12 ++++++
 4 files changed, 94 insertions(+)

diff --git a/docs/formatdomain.rst b/docs/formatdomain.rst
index 7ba32ea9c1..5db0aac77a 100644
--- a/docs/formatdomain.rst
+++ b/docs/formatdomain.rst
@@ -4363,6 +4363,7 @@ Network interfaces
        <mac address='52:54:00:5d:c7:9e'/>
        <boot order='1'/>
        <rom bar='off'/>
+       <acpi index='4'/>
      </interface>
    </devices>
    ...
@@ -4389,6 +4390,11 @@ when it's in the reserved VMware range by adding a ``type="static"`` attribute
 to the ``<mac/>`` element. Note that this attribute is useless if the provided
 MAC address is outside of the reserved VMWare ranges.
 
+:since:`Since 7.3.0`, one can set the ACPI index against network interfaces.
+With some operating systems (eg Linux with systemd), the ACPI index is used
+to provide network interface device naming, that is stable across changes
+in PCI addresses assigned to the device.
+
 :anchor:`<a id="elementsNICSVirtual"/>`
 
 Virtual network
diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng
index 2ff7862539..30108b6d4c 100644
--- a/docs/schemas/domaincommon.rng
+++ b/docs/schemas/domaincommon.rng
@@ -1441,6 +1441,9 @@
       <optional>
         <ref name="alias"/>
       </optional>
+      <optional>
+        <ref name="acpi"/>
+      </optional>
       <optional>
         <ref name="address"/>
       </optional>
@@ -2432,6 +2435,9 @@
         <optional>
           <ref name="alias"/>
         </optional>
+        <optional>
+          <ref name="acpi"/>
+        </optional>
         <optional>
           <ref name="address"/>
         </optional>
@@ -2860,6 +2866,9 @@
           <optional>
             <ref name="alias"/>
           </optional>
+          <optional>
+            <ref name="acpi"/>
+          </optional>
           <optional>
             <ref name="address"/>
           </optional>
@@ -3517,6 +3526,9 @@
       <optional>
         <ref name="alias"/>
       </optional>
+      <optional>
+        <ref name="acpi"/>
+      </optional>
       <optional>
         <ref name="address"/>
       </optional>
@@ -4143,6 +4155,9 @@
         <optional>
           <ref name="alias"/>
         </optional>
+        <optional>
+          <ref name="acpi"/>
+        </optional>
         <optional>
           <ref name="address"/>
         </optional>
@@ -4283,6 +4298,9 @@
       <optional>
         <ref name="alias"/>
       </optional>
+      <optional>
+        <ref name="acpi"/>
+      </optional>
       <optional>
         <ref name="address"/>
       </optional>
@@ -4535,6 +4553,9 @@
         <optional>
           <ref name="alias"/>
         </optional>
+        <optional>
+          <ref name="acpi"/>
+        </optional>
         <optional>
           <ref name="address"/>
         </optional>
@@ -4939,6 +4960,9 @@
       <optional>
         <ref name="alias"/>
       </optional>
+      <optional>
+        <ref name="acpi"/>
+      </optional>
       <optional>
         <ref name="address"/>
       </optional>
@@ -5008,6 +5032,9 @@
         <optional>
           <ref name="alias"/>
         </optional>
+        <optional>
+          <ref name="acpi"/>
+        </optional>
         <optional>
           <ref name="address"/>
         </optional>
@@ -5040,6 +5067,9 @@
         <optional>
           <ref name="alias"/>
         </optional>
+        <optional>
+          <ref name="acpi"/>
+        </optional>
         <optional>
           <ref name="address"/>
         </optional>
@@ -5118,6 +5148,9 @@
         <optional>
           <ref name="alias"/>
         </optional>
+        <optional>
+          <ref name="acpi"/>
+        </optional>
         <optional>
           <ref name="address"/>
         </optional>
@@ -5162,6 +5195,9 @@
       <optional>
         <ref name="alias"/>
       </optional>
+      <optional>
+        <ref name="acpi"/>
+      </optional>
       <optional>
         <ref name="address"/>
       </optional>
@@ -5189,6 +5225,9 @@
       <optional>
         <ref name="alias"/>
       </optional>
+      <optional>
+        <ref name="acpi"/>
+      </optional>
       <optional>
         <ref name="address"/>
       </optional>
@@ -5284,6 +5323,9 @@
         <optional>
           <ref name="alias"/>
         </optional>
+        <optional>
+          <ref name="acpi"/>
+        </optional>
         <optional>
           <element name="driver">
             <ref name="virtioOptions"/>
@@ -5386,6 +5428,9 @@
         <optional>
           <ref name="alias"/>
         </optional>
+        <optional>
+          <ref name="acpi"/>
+        </optional>
         <optional>
           <ref name="address"/>
         </optional>
@@ -5401,6 +5446,9 @@
         <optional>
           <ref name="alias"/>
         </optional>
+        <optional>
+          <ref name="acpi"/>
+        </optional>
         <optional>
           <ref name="address"/>
         </optional>
@@ -5420,6 +5468,9 @@
         <optional>
           <ref name="alias"/>
         </optional>
+        <optional>
+          <ref name="acpi"/>
+        </optional>
         <optional>
           <ref name="address"/>
         </optional>
@@ -5451,6 +5502,9 @@
         <optional>
           <ref name="alias"/>
         </optional>
+        <optional>
+          <ref name="acpi"/>
+        </optional>
         <optional>
           <ref name="deviceBoot"/>
         </optional>
@@ -6422,6 +6476,16 @@
     </element>
   </define>
 
+  <define name="acpi">
+    <element name="acpi">
+      <optional>
+        <attribute name="index">
+          <ref name="unsignedInt"/>
+        </attribute>
+      </optional>
+    </element>
+  </define>
+
   <define name="memorydev">
     <element name="memory">
       <attribute name="model">
@@ -6460,6 +6524,9 @@
         <optional>
           <ref name="alias"/>
         </optional>
+        <optional>
+          <ref name="acpi"/>
+        </optional>
       </interleave>
     </element>
   </define>
@@ -6551,6 +6618,9 @@
         <optional>
           <ref name="alias"/>
         </optional>
+        <optional>
+          <ref name="acpi"/>
+        </optional>
         <optional>
           <ref name="address"/>
         </optional>
@@ -7530,6 +7600,9 @@
         <optional>
           <ref name="alias"/>
         </optional>
+        <optional>
+          <ref name="acpi"/>
+        </optional>
         <optional>
           <ref name="address"/>
         </optional>
diff --git a/src/conf/device_conf.h b/src/conf/device_conf.h
index a51bdf10ee..af9a43bff2 100644
--- a/src/conf/device_conf.h
+++ b/src/conf/device_conf.h
@@ -159,6 +159,9 @@ struct _virDomainDeviceInfo {
     /* bootIndex is only used for disk, network interface, hostdev
      * and redirdev devices */
     unsigned int bootIndex;
+    /* Valid for any PCI device. Can be used for NIC to get
+     * stable numbering in Linux */
+    unsigned int acpiIndex;
 
     /* pciConnectFlags is only used internally during address
      * assignment, never saved and never reported.
diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index 1e72171586..ef921ae41a 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -6335,6 +6335,9 @@ virDomainDeviceInfoFormat(virBufferPtr buf,
         virBufferAddLit(buf, "/>\n");
     }
 
+    if (info->acpiIndex != 0)
+        virBufferAsprintf(buf, "<acpi index='%u'/>\n", info->acpiIndex);
+
     if (info->type == VIR_DOMAIN_DEVICE_ADDRESS_TYPE_NONE ||
         info->type == VIR_DOMAIN_DEVICE_ADDRESS_TYPE_VIRTIO_S390)
         /* We're done here */
@@ -6661,6 +6664,7 @@ virDomainDeviceInfoParseXML(virDomainXMLOptionPtr xmlopt,
     g_autofree char *romenabled = NULL;
     g_autofree char *rombar = NULL;
     g_autofree char *aliasStr = NULL;
+    g_autofree char *acpiIndex = NULL;
     VIR_XPATH_NODE_AUTORESTORE(ctxt)
 
     virDomainDeviceInfoClear(info);
@@ -6709,6 +6713,14 @@ virDomainDeviceInfoParseXML(virDomainXMLOptionPtr xmlopt,
         }
     }
 
+    acpiIndex = virXPathString("string(./acpi/@index)", ctxt);
+    if (acpiIndex &&
+        virStrToLong_ui(acpiIndex, NULL, 10, &info->acpiIndex) < 0) {
+        virReportError(VIR_ERR_XML_ERROR,
+                       _("Cannot parse ACPI index value '%s'"), acpiIndex);
+        goto cleanup;
+    }
+
     if ((address = virXPathNode("./address", ctxt)) &&
         virDomainDeviceAddressParseXML(address, info) < 0)
         goto cleanup;
-- 
2.30.2




More information about the libvir-list mailing list