Tue Aug 21 09:56:00 BST 2007 Richard W.M. Jones <rjones@redhat.com>

        * qemud/remote.c, qemud/remote_protocol.x, src/driver.h,
          src/internal.h, src/libvirt.c, src/libvirt_sym.version,
          src/qemu_driver.c, src/remote_internal.c, src/test.c:
          Add a private interface so that libvirt.c coordination
          functions can detect the availability of features in
          underlying drivers, using the VIR_DRV_SUPPORTS_FEATURE
          macro.

ChangeLog

+Tue Aug 21 09:56:00 BST 2007 Richard W.M. Jones <rjones@redhat.com>
+
+	* qemud/remote.c, qemud/remote_protocol.x, src/driver.h,
+	  src/internal.h, src/libvirt.c, src/libvirt_sym.version,
+	  src/qemu_driver.c, src/remote_internal.c, src/test.c:
+	  Add a private interface so that libvirt.c coordination
+	  functions can detect the availability of features in
+	  underlying drivers, using the VIR_DRV_SUPPORTS_FEATURE
+	  macro.
+
 Tue Aug 21 09:45:00 BST 2007 Richard W.M. Jones <rjones@redhat.com>
 
 	* src/xend_internal.c: Return the interface device name as

docs/hvsupport.html

@@ -5,7 +5,7 @@ This page documents which <a href="html/">libvirt calls</a> work on
 which hypervisors.
 </p><p>
 This information changes frequently.  This page was last checked or
-updated on <i>2007-06-29</i>.
+updated on <i>2007-08-20</i>.
 </p><h3>Domain functions</h3><p> x = not supported; empty cell means no information </p><table class="top_table"><tr><th> Function </th>
   <th> Since </th>
   <th> Xen </th>
@@ -259,7 +259,7 @@ updated on <i>2007-06-29</i>.
   <td> All </td>
   <td> All </td>
   <td> x </td>
-  <td> x </td>
+  <td> &#8805; 0.3.2 </td>
   <td> &#8805; 0.3.0 </td>
 </tr><tr><td> virDomainResume </td>
   <td> All </td>
@@ -271,7 +271,7 @@ updated on <i>2007-06-29</i>.
   <td> All </td>
   <td> All </td>
   <td> x </td>
-  <td> x </td>
+  <td> &#8805; 0.3.2 </td>
   <td> &#8805; 0.3.0 </td>
 </tr><tr><td> virDomainSetAutostart </td>
   <td> 0.2.1 </td>

qemud/remote.c

@@ -417,6 +417,18 @@ remoteDispatchClose (struct qemud_client *client, remote_message_header *req,
     return rv;
 }
 
+static int
+remoteDispatchSupportsFeature (struct qemud_client *client, remote_message_header *req,
+                               remote_supports_feature_args *args, remote_supports_feature_ret *ret)
+{
+    CHECK_CONN(client);
+
+    ret->supported = __virDrvSupportsFeature (client->conn, args->feature);
+    if (ret->supported == -1) return -1;
+
+    return 0;
+}
+
 static int
 remoteDispatchGetType (struct qemud_client *client, remote_message_header *req,
                        void *args ATTRIBUTE_UNUSED, remote_get_type_ret *ret)

qemud/remote_dispatch_localvars.h

@@ -20,9 +20,9 @@ remote_domain_get_os_type_ret lv_remote_domain_get_os_type_ret;
 remote_domain_get_autostart_args lv_remote_domain_get_autostart_args;
 remote_domain_get_autostart_ret lv_remote_domain_get_autostart_ret;
 remote_domain_set_vcpus_args lv_remote_domain_set_vcpus_args;
-remote_get_hostname_ret lv_remote_get_hostname_ret;
 remote_domain_get_scheduler_type_args lv_remote_domain_get_scheduler_type_args;
 remote_domain_get_scheduler_type_ret lv_remote_domain_get_scheduler_type_ret;
+remote_get_hostname_ret lv_remote_get_hostname_ret;
 remote_network_undefine_args lv_remote_network_undefine_args;
 remote_domain_create_args lv_remote_domain_create_args;
 remote_domain_suspend_args lv_remote_domain_suspend_args;
@@ -67,6 +67,8 @@ remote_domain_get_info_args lv_remote_domain_get_info_args;
 remote_domain_get_info_ret lv_remote_domain_get_info_ret;
 remote_network_create_args lv_remote_network_create_args;
 remote_num_of_defined_networks_ret lv_remote_num_of_defined_networks_ret;
+remote_supports_feature_args lv_remote_supports_feature_args;
+remote_supports_feature_ret lv_remote_supports_feature_ret;
 remote_domain_lookup_by_name_args lv_remote_domain_lookup_by_name_args;
 remote_domain_lookup_by_name_ret lv_remote_domain_lookup_by_name_ret;
 remote_network_lookup_by_uuid_args lv_remote_network_lookup_by_uuid_args;

qemud/remote_dispatch_proc_switch.h

@@ -431,3 +431,12 @@ case REMOTE_PROC_OPEN:
 	args = (char *) &lv_remote_open_args;
 	memset (&lv_remote_open_args, 0, sizeof lv_remote_open_args);
 	break;
+case REMOTE_PROC_SUPPORTS_FEATURE:
+	fn = (dispatch_fn) remoteDispatchSupportsFeature;
+	args_filter = (xdrproc_t) xdr_remote_supports_feature_args;
+	args = (char *) &lv_remote_supports_feature_args;
+	memset (&lv_remote_supports_feature_args, 0, sizeof lv_remote_supports_feature_args);
+	ret_filter = (xdrproc_t) xdr_remote_supports_feature_ret;
+	ret = (char *) &lv_remote_supports_feature_ret;
+	memset (&lv_remote_supports_feature_ret, 0, sizeof lv_remote_supports_feature_ret);
+	break;

qemud/remote_dispatch_prototypes.h

@@ -61,3 +61,4 @@ static int remoteDispatchNumOfDefinedNetworks (struct qemud_client *client, remo
 static int remoteDispatchNumOfDomains (struct qemud_client *client, remote_message_header *req, void *args, remote_num_of_domains_ret *ret);
 static int remoteDispatchNumOfNetworks (struct qemud_client *client, remote_message_header *req, void *args, remote_num_of_networks_ret *ret);
 static int remoteDispatchOpen (struct qemud_client *client, remote_message_header *req, remote_open_args *args, void *ret);
+static int remoteDispatchSupportsFeature (struct qemud_client *client, remote_message_header *req, remote_supports_feature_args *args, remote_supports_feature_ret *ret);

qemud/remote_protocol.c

@@ -177,6 +177,24 @@ xdr_remote_open_args (XDR *xdrs, remote_open_args *objp)
 	return TRUE;
 }
 
+bool_t
+xdr_remote_supports_feature_args (XDR *xdrs, remote_supports_feature_args *objp)
+{
+
+	 if (!xdr_int (xdrs, &objp->feature))
+		 return FALSE;
+	return TRUE;
+}
+
+bool_t
+xdr_remote_supports_feature_ret (XDR *xdrs, remote_supports_feature_ret *objp)
+{
+
+	 if (!xdr_int (xdrs, &objp->supported))
+		 return FALSE;
+	return TRUE;
+}
+
 bool_t
 xdr_remote_get_type_ret (XDR *xdrs, remote_get_type_ret *objp)
 {

qemud/remote_protocol.h

@@ -95,6 +95,16 @@ struct remote_open_args {
 };
 typedef struct remote_open_args remote_open_args;
 
+struct remote_supports_feature_args {
+	int feature;
+};
+typedef struct remote_supports_feature_args remote_supports_feature_args;
+
+struct remote_supports_feature_ret {
+	int supported;
+};
+typedef struct remote_supports_feature_ret remote_supports_feature_ret;
+
 struct remote_get_type_ret {
 	remote_nonnull_string type;
 };
@@ -632,6 +642,7 @@ enum remote_procedure {
 	REMOTE_PROC_DOMAIN_GET_SCHEDULER_PARAMETERS = 57,
 	REMOTE_PROC_DOMAIN_SET_SCHEDULER_PARAMETERS = 58,
 	REMOTE_PROC_GET_HOSTNAME = 59,
+	REMOTE_PROC_SUPPORTS_FEATURE = 60,
 };
 typedef enum remote_procedure remote_procedure;
 
@@ -673,6 +684,8 @@ extern  bool_t xdr_remote_vcpu_info (XDR *, remote_vcpu_info*);
 extern  bool_t xdr_remote_sched_param_value (XDR *, remote_sched_param_value*);
 extern  bool_t xdr_remote_sched_param (XDR *, remote_sched_param*);
 extern  bool_t xdr_remote_open_args (XDR *, remote_open_args*);
+extern  bool_t xdr_remote_supports_feature_args (XDR *, remote_supports_feature_args*);
+extern  bool_t xdr_remote_supports_feature_ret (XDR *, remote_supports_feature_ret*);
 extern  bool_t xdr_remote_get_type_ret (XDR *, remote_get_type_ret*);
 extern  bool_t xdr_remote_get_version_ret (XDR *, remote_get_version_ret*);
 extern  bool_t xdr_remote_get_hostname_ret (XDR *, remote_get_hostname_ret*);
@@ -774,6 +787,8 @@ extern bool_t xdr_remote_vcpu_info ();
 extern bool_t xdr_remote_sched_param_value ();
 extern bool_t xdr_remote_sched_param ();
 extern bool_t xdr_remote_open_args ();
+extern bool_t xdr_remote_supports_feature_args ();
+extern bool_t xdr_remote_supports_feature_ret ();
 extern bool_t xdr_remote_get_type_ret ();
 extern bool_t xdr_remote_get_version_ret ();
 extern bool_t xdr_remote_get_hostname_ret ();

qemud/remote_protocol.x

@@ -170,6 +170,14 @@ struct remote_open_args {
     int flags;
 };
 
+struct remote_supports_feature_args {
+    int feature;
+};
+
+struct remote_supports_feature_ret {
+    int supported;
+};
+
 struct remote_get_type_ret {
     remote_nonnull_string type;
 };
@@ -610,7 +618,8 @@ enum remote_procedure {
     REMOTE_PROC_DOMAIN_GET_SCHEDULER_TYPE = 56,
     REMOTE_PROC_DOMAIN_GET_SCHEDULER_PARAMETERS = 57,
     REMOTE_PROC_DOMAIN_SET_SCHEDULER_PARAMETERS = 58,
-    REMOTE_PROC_GET_HOSTNAME = 59
+    REMOTE_PROC_GET_HOSTNAME = 59,
+    REMOTE_PROC_SUPPORTS_FEATURE = 60
 };
 
 /* Custom RPC structure. */

src/driver.h

@@ -44,12 +44,42 @@ typedef enum {
     VIR_DRV_OPEN_ERROR = -2,
 } virDrvOpenStatus;
 
+/* Feature detection.  This is a libvirt-private interface for determining
+ * what features are supported by the driver.
+ *
+ * The remote driver passes features through to the real driver at the
+ * remote end unmodified, except if you query a VIR_DRV_FEATURE_REMOTE*
+ * feature.
+ */
+    /* Driver supports V1-style virDomainMigrate, ie. domainMigratePrepare/
+     * domainMigratePerform/domainMigrateFinish.
+     */
+#define VIR_DRV_FEATURE_MIGRATION_V1 1
+
+    /* Driver is not local. */
+#define VIR_DRV_FEATURE_REMOTE 2
+
+/* Internal feature-detection macro.  Don't call drv->supports_feature
+ * directly, because it may be NULL, use this macro instead.
+ *
+ * Note that you must check for errors.
+ *
+ * Returns:
+ *   >= 1  Feature is supported.
+ *   0     Feature is not supported.
+ *   -1    Error.
+ */
+#define VIR_DRV_SUPPORTS_FEATURE(drv,conn,feature)                      \
+    ((drv)->supports_feature ? (drv)->supports_feature((conn),(feature)) : 0)
+
 typedef virDrvOpenStatus
 	(*virDrvOpen)			(virConnectPtr conn,
 					 const char *name,
 					 int flags);
 typedef int
 	(*virDrvClose)			(virConnectPtr conn);
+typedef int
+    (*virDrvSupportsFeature) (virConnectPtr conn, int feature);
 typedef const char *
 	(*virDrvGetType)		(virConnectPtr conn);
 typedef int
@@ -202,6 +232,7 @@ struct _virDriver {
 	unsigned long ver;	/* the version of the backend */
 	virDrvOpen			open;
 	virDrvClose			close;
+    virDrvSupportsFeature   supports_feature;
 	virDrvGetType			type;
 	virDrvGetVersion		version;
     virDrvGetHostname       getHostname;

src/internal.h

@@ -229,6 +229,8 @@ int __virStateActive(void);
 #define virStateReload() __virStateReload()
 #define virStateActive() __virStateActive()
 
+int __virDrvSupportsFeature (virConnectPtr conn, int feature);
+
 #ifdef __cplusplus
 }
 #endif                          /* __cplusplus */

src/libvirt.c

@@ -540,6 +540,20 @@ virConnectClose(virConnectPtr conn)
     return (0);
 }
 
+/* Not for public use.  This function is part of the internal
+ * implementation of driver features in the remote case.
+ */
+int
+__virDrvSupportsFeature (virConnectPtr conn, int feature)
+{
+    DEBUG("conn=%p, feature=%d", conn, feature);
+
+    if (!VIR_IS_CONNECT(conn))
+        return (-1);
+
+    return VIR_DRV_SUPPORTS_FEATURE (conn->driver, conn, feature);
+}
+
 /**
  * virConnectGetType:
  * @conn: pointer to the hypervisor connection

src/libvirt_sym.version

@@ -116,5 +116,7 @@
  	__virStateReload;
  	__virStateActive;
 
+	__virDrvSupportsFeature;
+
     local: *;
 };

src/qemu_driver.c

@@ -2618,6 +2618,7 @@ static virDriver qemuDriver = {
     LIBVIR_VERSION_NUMBER,
     qemudOpen, /* open */
     qemudClose, /* close */
+    NULL, /* supports_feature */
     qemudGetType, /* type */
     qemudGetVersion, /* version */
     NULL, /* hostname */

src/remote_internal.c

@@ -1195,6 +1195,27 @@ remoteClose (virConnectPtr conn)
     return ret;
 }
 
+static int
+remoteSupportsFeature (virConnectPtr conn, int feature)
+{
+    remote_supports_feature_args args;
+    remote_supports_feature_ret ret;
+    GET_PRIVATE (conn, -1);
+
+    /* VIR_DRV_FEATURE_REMOTE* features are handled directly. */
+    if (feature == VIR_DRV_FEATURE_REMOTE) return 1;
+
+    args.feature = feature;
+
+    memset (&ret, 0, sizeof ret);
+    if (call (conn, priv, 0, REMOTE_PROC_SUPPORTS_FEATURE,
+              (xdrproc_t) xdr_remote_supports_feature_args, (char *) &args,
+              (xdrproc_t) xdr_remote_supports_feature_ret, (char *) &ret) == -1)
+        return -1;
+
+    return ret.supported;
+}
+
 /* Unfortunately this function is defined to return a static string.
  * Since the remote end always answers with the same type (for a
  * single connection anyway) we cache the type in the connection's
@@ -2898,6 +2919,7 @@ static virDriver driver = {
     .ver = REMOTE_PROTOCOL_VERSION,
     .open = remoteOpen,
     .close = remoteClose,
+    .supports_feature = remoteSupportsFeature,
 	.type = remoteType,
 	.version = remoteVersion,
     .getHostname = remoteGetHostname,

src/test.c

@@ -1920,6 +1920,7 @@ static virDriver testDriver = {
     LIBVIR_VERSION_NUMBER,
     testOpen, /* open */
     testClose, /* close */
+    NULL, /* supports_feature */
     NULL, /* type */
     testGetVersion, /* version */
     testGetHostname, /* hostname */