domain: add rendernode attribute on <accel>

vhost-user-gpu helper takes --render-node option to specify on which
GPU should the renderning be done.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>

docs/formatdomain.html.in

@@ -7082,6 +7082,12 @@ qemu-kvm -net nic,model=? /dev/null
         <dd>Enable 3D acceleration (for vbox driver
         <span class="since">since 0.7.1</span>, qemu driver
         <span class="since">since 1.3.0</span>)</dd>
+
+        <dt><code>rendernode</code></dt>
+        <dd>Absolute path to a host's DRI device to be used for
+        rendering (for 'vhostuser' driver only, <span
+        class="since">since 5.8.0</span>). If none is specified,
+        libvirt will pick one available.</dd>
         </dl>
       </dd>
 

docs/schemas/domaincommon.rng

@@ -3648,6 +3648,11 @@
                   <ref name="virYesNo"/>
                 </attribute>
               </optional>
+              <optional>
+                <attribute name="rendernode">
+                  <ref name="absFilePath"/>
+                </attribute>
+              </optional>
             </element>
           </optional>
         </element>

src/conf/domain_conf.c

@@ -2840,6 +2840,8 @@ virDomainVideoDefClear(virDomainVideoDefPtr def)
 
     virDomainDeviceInfoClear(&def->info);
 
+    if (def->accel)
+        VIR_FREE(def->accel->rendernode);
     VIR_FREE(def->accel);
     VIR_FREE(def->virtio);
     VIR_FREE(def->driver);
@@ -6279,6 +6281,11 @@ virDomainVideoDefValidate(const virDomainVideoDef *video,
         break;
     case VIR_DOMAIN_VIDEO_BACKEND_TYPE_DEFAULT:
     case VIR_DOMAIN_VIDEO_BACKEND_TYPE_QEMU:
+        if (video->accel && video->accel->rendernode) {
+            virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                           _("unsupported rendernode accel attribute without 'vhostuser'"));
+            return -1;
+        }
         break;
     case VIR_DOMAIN_VIDEO_BACKEND_TYPE_LAST:
     default:
@@ -15341,6 +15348,7 @@ virDomainVideoAccelDefParseXML(xmlNodePtr node)
     int val;
     VIR_AUTOFREE(char *) accel2d = NULL;
     VIR_AUTOFREE(char *) accel3d = NULL;
+    VIR_AUTOFREE(char *) rendernode = NULL;
 
     cur = node->children;
     while (cur != NULL) {
@@ -15349,12 +15357,13 @@ virDomainVideoAccelDefParseXML(xmlNodePtr node)
                 virXMLNodeNameEqual(cur, "acceleration")) {
                 accel3d = virXMLPropString(cur, "accel3d");
                 accel2d = virXMLPropString(cur, "accel2d");
+                rendernode = virXMLPropString(cur, "rendernode");
             }
         }
         cur = cur->next;
     }
 
-    if (!accel3d && !accel2d)
+    if (!accel3d && !accel2d && !rendernode)
         return NULL;
 
     if (VIR_ALLOC(def) < 0)
@@ -15378,6 +15387,9 @@ virDomainVideoAccelDefParseXML(xmlNodePtr node)
         def->accel2d = val;
     }
 
+    if (rendernode)
+        def->rendernode = virFileSanitizePath(rendernode);
+
  cleanup:
     return def;
 }
@@ -26506,6 +26518,7 @@ virDomainVideoAccelDefFormat(virBufferPtr buf,
         virBufferAsprintf(buf, " accel2d='%s'",
                           virTristateBoolTypeToString(def->accel2d));
     }
+    virBufferEscapeString(buf, " rendernode='%s'", def->rendernode);
     virBufferAddLit(buf, "/>\n");
 }
 

src/conf/domain_conf.h

@@ -1417,6 +1417,7 @@ VIR_ENUM_DECL(virDomainVideoVGAConf);
 struct _virDomainVideoAccelDef {
     int accel2d; /* enum virTristateBool */
     int accel3d; /* enum virTristateBool */
+    char *rendernode;
 };
 
 

tests/qemuxml2argvdata/virtio-options.xml

@@ -75,7 +75,7 @@
     <video>
       <driver iommu='on' ats='on' name='vhostuser'/>
       <model type='virtio' heads='1' primary='yes'>
-        <acceleration accel3d='yes'/>
+        <acceleration accel3d='yes' rendernode='/dev/dri/test'/>
       </model>
       <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/>
     </video>