[PATCH v3 10/15] xenstore: make use of the "xenstore domain" flag

[Juergen Gross <jgross@suse.com>]

Create the xenstore domain with the xenstore flag specified. This
enables us to test whether such a domain is already running before
we create it. As there ought to be only one xenstore in the system
we don't need to start another one.

Signed-off-by: Juergen Gross <jgross@suse.com>
---
V3: omit dom0 when checking for xenstore domain as suggested by Ian
    Campbell
    log an error in case of an error when obtaining domain info as
    requested by Ian Campbell
---
 tools/helpers/init-xenstore-domain.c | 32 ++++++++++++++++++++++++++++++--
 1 file changed, 30 insertions(+), 2 deletions(-)

diff --git a/tools/helpers/init-xenstore-domain.c b/tools/helpers/init-xenstore-domain.c
index ff9968f..ecced04 100644
--- a/tools/helpers/init-xenstore-domain.c
+++ b/tools/helpers/init-xenstore-domain.c
@@ -71,7 +71,8 @@ static int build(xc_interface *xch)
     {
         ssid = SECINITSID_DOMU;
     }
-    rv = xc_domain_create(xch, ssid, handle, 0, &domid, NULL);
+    rv = xc_domain_create(xch, ssid, handle, XEN_DOMCTL_CDF_xs_domain,
+                          &domid, NULL);
     if ( rv )
     {
         fprintf(stderr, "xc_domain_create failed\n");
@@ -186,6 +187,28 @@ err:
     return rv;
 }
 
+static int check_domain(xc_interface *xch)
+{
+    xc_dominfo_t info;
+    uint32_t dom;
+    int ret;
+
+    dom = 1;
+    while ( (ret = xc_domain_getinfo(xch, dom, 1, &info)) == 1 )
+    {
+        if ( info.xenstore )
+            return 1;
+        dom = info.domid + 1;
+    }
+    if ( ret < 0 && errno != ESRCH )
+    {
+        fprintf(stderr, "xc_domain_getinfo failed\n");
+        return ret;
+    }
+
+    return 0;
+}
+
 int main(int argc, char** argv)
 {
     int opt;
@@ -229,7 +252,12 @@ int main(int argc, char** argv)
         return 1;
     }
 
-    rv = build(xch);
+    rv = check_domain(xch);
+
+    if ( !rv )
+        rv = build(xch);
+    else if ( rv > 0 )
+        fprintf(stderr, "xenstore domain already present.\n");
 
     xc_interface_close(xch);
 
-- 
2.6.2