Xen: Fake versions in xencapstest

virInitialize() → xenRegister() → xenhypervisorInit() determines the
version of the Hypervisor. This breaks xencapstest when building as root
on a dom0 system, since xenHypervisorBuildCapabilities() adds the "hap"
and "viridian" features based on the detected version.

Add an optional parameter to xenhypervisorInit() to disable automatic
detection of the Hypervisor version. The passed in arguments are used
instead.
Signed-off-by: NPhilipp Hahn <hahn@univention.de>

src/xen/xen_driver.c

@@ -2272,7 +2272,7 @@ int
 xenRegister (void)
 {
     /* Ignore failures here. */
-    (void) xenHypervisorInit ();
+    (void) xenHypervisorInit (NULL);
 
 #ifdef WITH_LIBVIRTD
     if (virRegisterStateDriver (&state_driver) == -1) return -1;

src/xen/xen_hypervisor.c

@@ -1951,12 +1951,16 @@ virXen_getvcpusinfo(int handle, int id, unsigned int vcpu, virVcpuInfoPtr ipt,
 
 /**
  * xenHypervisorInit:
+ * @override_versions: pointer to optional struct xenHypervisorVersions with
+ *     version information used instead of automatic version detection.
  *
  * Initialize the hypervisor layer. Try to detect the kind of interface
  * used i.e. pre or post changeset 10277
+ *
+ * Returns 0 or -1 in case of failure
  */
 int
-xenHypervisorInit(void)
+xenHypervisorInit(struct xenHypervisorVersions *override_versions)
 {
     int fd, ret, cmd, errcode;
     hypercall_t hc;
@@ -2007,6 +2011,12 @@ xenHypervisorInit(void)
         return -1;
     }
 
+    if (override_versions) {
+      hv_versions = *override_versions;
+      in_init = 0;
+      return 0;
+    }
+
     /* Xen hypervisor version detection begins. */
     ret = open(XEN_HYPERVISOR_SOCKET, O_RDWR);
     if (ret < 0) {
@@ -2188,7 +2198,7 @@ xenHypervisorOpen(virConnectPtr conn,
     virCheckFlags(VIR_CONNECT_RO, VIR_DRV_OPEN_ERROR);
 
     if (initialized == 0)
-        if (xenHypervisorInit() == -1)
+        if (xenHypervisorInit(NULL) == -1)
             return -1;
 
     priv->handle = -1;

src/xen/xen_hypervisor.h

@@ -26,7 +26,7 @@ struct xenHypervisorVersions {
 };
 
 extern struct xenUnifiedDriver xenHypervisorDriver;
-int    xenHypervisorInit                 (void);
+int xenHypervisorInit(struct xenHypervisorVersions *override_versions);
 
 virCapsPtr xenHypervisorMakeCapabilities (virConnectPtr conn);
 

tests/xencapstest.c

@@ -145,11 +145,21 @@ static int testXenppc64(const void *data ATTRIBUTE_UNUSED) {
 }
 
 
+/* Fake initialization data for xenHypervisorInit(). Must be initialized
+ * explicitly before the implicit call via virInitialize(). */
+static struct xenHypervisorVersions hv_versions = {
+    .hv = 0,
+    .hypervisor = 2,
+    .sys_interface = -1,
+    .dom_interface = -1,
+};
+
 static int
 mymain(void)
 {
     int ret = 0;
 
+    xenHypervisorInit(&hv_versions);
     virInitialize();
 
     if (virtTestRun("Capabilities for i686, no PAE, no HVM",