xenconfig: Add support for max_event_channels

Add support in the domXML<->native config converter for max_event_channels.
The parser and formater functions for max_grant_frames were reworked to
also parse max_event_channels. In doing so the xenbus controller is added
earlier in the config parsing, requiring a small adjustment to one of the
existing tests. Include a new test for the event channel conversion.
Signed-off-by: NJim Fehlig <jfehlig@suse.com>
Reviewed-by: NDaniel P. Berrangé <berrange@redhat.com>

src/libxl/xen_xl.c

@@ -597,19 +597,12 @@ xenParseXLVnuma(virConfPtr conf,
 }
 #endif
 
-#ifdef LIBXL_HAVE_BUILDINFO_GRANT_LIMITS
 static int
-xenParseXLGntLimits(virConfPtr conf, virDomainDefPtr def)
+xenParseXLXenbusLimits(virConfPtr conf, virDomainDefPtr def)
 {
-    unsigned long max_gntframes;
     int ctlr_idx;
     virDomainControllerDefPtr xenbus_ctlr;
-
-    if (xenConfigGetULong(conf, "max_grant_frames", &max_gntframes, 0) < 0)
-        return -1;
-
-    if (max_gntframes <= 0)
-        return 0;
+    unsigned long limit;
 
     ctlr_idx = virDomainControllerFindByType(def, VIR_DOMAIN_CONTROLLER_TYPE_XENBUS);
     if (ctlr_idx == -1)
@@ -620,10 +613,20 @@ xenParseXLGntLimits(virConfPtr conf, virDomainDefPtr def)
     if (xenbus_ctlr == NULL)
         return -1;
 
-    xenbus_ctlr->opts.xenbusopts.maxGrantFrames = max_gntframes;
+    if (xenConfigGetULong(conf, "max_event_channels", &limit, 0) < 0)
+        return -1;
+    if (limit > 0)
+        xenbus_ctlr->opts.xenbusopts.maxEventChannels = limit;
+
+#ifdef LIBXL_HAVE_BUILDINFO_GRANT_LIMITS
+    if (xenConfigGetULong(conf, "max_grant_frames", &limit, 0) < 0)
+        return -1;
+    if (limit > 0)
+        xenbus_ctlr->opts.xenbusopts.maxGrantFrames = limit;
+#endif
+
     return 0;
 }
-#endif
 
 static int
 xenParseXLDiskSrc(virDomainDiskDefPtr disk, char *srcstr)
@@ -1180,10 +1183,8 @@ xenParseXL(virConfPtr conf,
         goto cleanup;
 #endif
 
-#ifdef LIBXL_HAVE_BUILDINFO_GRANT_LIMITS
-    if (xenParseXLGntLimits(conf, def) < 0)
+    if (xenParseXLXenbusLimits(conf, def) < 0)
         goto cleanup;
-#endif
 
     if (xenParseXLCPUID(conf, def) < 0)
         goto cleanup;
@@ -1532,23 +1533,31 @@ xenFormatXLDomainVnuma(virConfPtr conf,
 }
 #endif
 
-#ifdef LIBXL_HAVE_BUILDINFO_GRANT_LIMITS
 static int
-xenFormatXLGntLimits(virConfPtr conf, virDomainDefPtr def)
+xenFormatXLXenbusLimits(virConfPtr conf, virDomainDefPtr def)
 {
     size_t i;
 
     for (i = 0; i < def->ncontrollers; i++) {
-        if (def->controllers[i]->type == VIR_DOMAIN_CONTROLLER_TYPE_XENBUS &&
-            def->controllers[i]->opts.xenbusopts.maxGrantFrames > 0) {
-            if (xenConfigSetInt(conf, "max_grant_frames",
-                                def->controllers[i]->opts.xenbusopts.maxGrantFrames) < 0)
-                return -1;
+        if (def->controllers[i]->type == VIR_DOMAIN_CONTROLLER_TYPE_XENBUS) {
+            if (def->controllers[i]->opts.xenbusopts.maxEventChannels > 0) {
+                if (xenConfigSetInt(conf, "max_event_channels",
+                                    def->controllers[i]->opts.xenbusopts.maxEventChannels) < 0)
+                    return -1;
+            }
+
+#ifdef LIBXL_HAVE_BUILDINFO_GRANT_LIMITS
+            if (def->controllers[i]->opts.xenbusopts.maxGrantFrames > 0) {
+                if (xenConfigSetInt(conf, "max_grant_frames",
+                                    def->controllers[i]->opts.xenbusopts.maxGrantFrames) < 0)
+                    return -1;
+            }
+#endif
         }
     }
+
     return 0;
 }
-#endif
 
 static char *
 xenFormatXLDiskSrcNet(virStorageSourcePtr src)
@@ -2191,10 +2200,8 @@ xenFormatXL(virDomainDefPtr def, virConnectPtr conn)
         return NULL;
 #endif
 
-#ifdef LIBXL_HAVE_BUILDINFO_GRANT_LIMITS
-    if (xenFormatXLGntLimits(conf, def) < 0)
+    if (xenFormatXLXenbusLimits(conf, def) < 0)
         return NULL;
-#endif
 
     if (xenFormatXLDomainDisks(conf, def) < 0)
         return NULL;

tests/xlconfigdata/test-max-eventchannels.cfg

+name = "XenGuest1"
+uuid = "45b60f51-88a9-47a8-a3b3-5e66d71b2283"
+maxmem = 512
+memory = 512
+vcpus = 1
+localtime = 0
+on_poweroff = "preserve"
+on_reboot = "restart"
+on_crash = "preserve"
+vif = [ "mac=5a:36:0e:be:00:09" ]
+bootloader = "/usr/bin/pygrub"
+max_event_channels = 2047
+disk = [ "format=qcow2,vdev=xvda,access=rw,backendtype=qdisk,target=/var/lib/xen/images/debian/disk.qcow2" ]

tests/xlconfigdata/test-max-eventchannels.xml

+<domain type='xen'>
+  <name>XenGuest1</name>
+  <uuid>45b60f51-88a9-47a8-a3b3-5e66d71b2283</uuid>
+  <memory unit='KiB'>524288</memory>
+  <currentMemory unit='KiB'>524288</currentMemory>
+  <vcpu placement='static'>1</vcpu>
+  <bootloader>/usr/bin/pygrub</bootloader>
+  <os>
+    <type arch='x86_64' machine='xenpv'>linux</type>
+  </os>
+  <clock offset='utc' adjustment='reset'/>
+  <on_poweroff>preserve</on_poweroff>
+  <on_reboot>restart</on_reboot>
+  <on_crash>preserve</on_crash>
+  <devices>
+    <disk type='file' device='disk'>
+      <driver name='qemu' type='qcow2'/>
+      <source file='/var/lib/xen/images/debian/disk.qcow2'/>
+      <target dev='xvda' bus='xen'/>
+    </disk>
+    <controller type='xenbus' index='0' maxEventChannels='2047'/>
+    <interface type='ethernet'>
+      <mac address='5a:36:0e:be:00:09'/>
+    </interface>
+    <console type='pty'>
+      <target type='xen' port='0'/>
+    </console>
+    <input type='mouse' bus='xen'/>
+    <input type='keyboard' bus='xen'/>
+    <memballoon model='xen'/>
+  </devices>
+</domain>

tests/xlconfigdata/test-usbctrl.xml

@@ -18,8 +18,8 @@
       <source file='/var/lib/xen/images/debian/disk.qcow2'/>
       <target dev='xvda' bus='xen'/>
     </disk>
-    <controller type='usb' index='0' model='qusb2' ports='6'/>
     <controller type='xenbus' index='0'/>
+    <controller type='usb' index='0' model='qusb2' ports='6'/>
     <interface type='ethernet'>
       <mac address='5a:36:0e:be:00:09'/>
     </interface>

tests/xlconfigtest.c

@@ -294,6 +294,8 @@ mymain(void)
     DO_TEST("max-gntframes");
 #endif
 
+    DO_TEST("max-eventchannels");
+
     DO_TEST("vif-typename");
     DO_TEST("vif-multi-ip");
     DO_TEST("usb");