[PATCH v2 07/13] xenstore: add error messages to init-xenstore-domain

[Juergen Gross <jgross@suse.com>]

Additional add some diagnostic messages to the program to have an idea
why it failed.

Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
---
 tools/helpers/init-xenstore-domain.c | 104 ++++++++++++++++++++++++++++-------
 1 file changed, 83 insertions(+), 21 deletions(-)

diff --git a/tools/helpers/init-xenstore-domain.c b/tools/helpers/init-xenstore-domain.c
index 6dffaef..d3abec0 100644
--- a/tools/helpers/init-xenstore-domain.c
+++ b/tools/helpers/init-xenstore-domain.c
@@ -10,6 +10,7 @@
 #include <xc_dom.h>
 #include <xenstore.h>
 #include <xen/sys/xenbus_dev.h>
+#include <xen-xsm/flask/flask.h>
 
 static uint32_t domid = ~0;
 
@@ -24,52 +25,103 @@ static int build(xc_interface *xch, int argc, char** argv)
     int limit_kb = (maxmem + 1)*1024;
 
     xs_fd = open("/dev/xen/xenbus_backend", O_RDWR);
-    if (xs_fd == -1) return -1;
+    if (xs_fd == -1) {
+        fprintf(stderr, "Could not open /dev/xen/xenbus_backend\n");
+        return -1;
+    }
 
     rv = xc_flask_context_to_sid(xch, argv[3], strlen(argv[3]), &ssid);
-    if (rv) goto err;
+    if (rv) {
+        fprintf(stderr, "xc_flask_context_to_sid failed\n");
+        goto err;
+    }
     rv = xc_domain_create(xch, ssid, handle, 0, &domid, NULL);
-    if (rv) goto err;
+    if (rv) {
+        fprintf(stderr, "xc_domain_create failed\n");
+        goto err;
+    }
     rv = xc_domain_max_vcpus(xch, domid, 1);
-    if (rv) goto err;
+    if (rv) {
+        fprintf(stderr, "xc_domain_max_vcpus failed\n");
+        goto err;
+    }
     rv = xc_domain_setmaxmem(xch, domid, limit_kb);
-    if (rv) goto err;
+    if (rv) {
+        fprintf(stderr, "xc_domain_setmaxmem failed\n");
+        goto err;
+    }
     rv = xc_domain_set_memmap_limit(xch, domid, limit_kb);
-    if (rv) goto err;
+    if (rv) {
+        fprintf(stderr, "xc_domain_set_memmap_limit failed\n");
+        goto err;
+    }
 
     rv = ioctl(xs_fd, IOCTL_XENBUS_BACKEND_SETUP, domid);
-    if (rv < 0) goto err;
+    if (rv < 0) {
+        fprintf(stderr, "Xenbus setup ioctl failed\n");
+        goto err;
+    }
     snprintf(cmdline, 512, "--event %d --internal-db", rv);
 
     dom = xc_dom_allocate(xch, cmdline, NULL);
     rv = xc_dom_kernel_file(dom, argv[1]);
-    if (rv) goto err;
+    if (rv) {
+        fprintf(stderr, "xc_dom_kernel_file failed\n");
+        goto err;
+    }
 
     if (argc > 4) {
         rv = xc_dom_ramdisk_file(dom, argv[4]);
-        if (rv) goto err;
+        if (rv) {
+            fprintf(stderr, "xc_dom_ramdisk_file failed\n");
+            goto err;
+        }
     }
 
     rv = xc_dom_boot_xen_init(dom, xch, domid);
-    if (rv) goto err;
+    if (rv) {
+        fprintf(stderr, "xc_dom_boot_xen_init failed\n");
+        goto err;
+    }
     rv = xc_dom_parse_image(dom);
-    if (rv) goto err;
+    if (rv) {
+        fprintf(stderr, "xc_dom_parse_image failed\n");
+        goto err;
+    }
     rv = xc_dom_mem_init(dom, maxmem);
-    if (rv) goto err;
+    if (rv) {
+        fprintf(stderr, "xc_dom_mem_init failed\n");
+        goto err;
+    }
     rv = xc_dom_boot_mem_init(dom);
-    if (rv) goto err;
+    if (rv) {
+        fprintf(stderr, "xc_dom_boot_mem_init failed\n");
+        goto err;
+    }
     rv = xc_dom_build_image(dom);
-    if (rv) goto err;
+    if (rv) {
+        fprintf(stderr, "xc_dom_build_image failed\n");
+        goto err;
+    }
     rv = xc_dom_boot_image(dom);
-    if (rv) goto err;
+    if (rv) {
+        fprintf(stderr, "xc_dom_boot_image failed\n");
+        goto err;
+    }
 
     xc_dom_release(dom);
     dom = NULL;
 
     rv = xc_domain_set_virq_handler(xch, domid, VIRQ_DOM_EXC);
-    if (rv) goto err;
+    if (rv) {
+        fprintf(stderr, "xc_domain_set_virq_handler failed\n");
+        goto err;
+    }
     rv = xc_domain_unpause(xch, domid);
-    if (rv) goto err;
+    if (rv) {
+        fprintf(stderr, "xc_domain_unpause failed\n");
+        goto err;
+    }
 
     return 0;
 
@@ -90,12 +142,17 @@ int main(int argc, char** argv)
     int rv, fd;
 
     if (argc < 4 || argc > 5) {
-        printf("Use: %s <xenstore-kernel> <memory_mb> <flask-label> [<ramdisk-file>]\n", argv[0]);
+        fprintf(stderr,
+            "Use: %s <xenstore-kernel> <memory_mb> <flask-label> [<ramdisk-file>]\n",
+            argv[0]);
         return 2;
     }
 
     xch = xc_interface_open(NULL, NULL, 0);
-    if (!xch) return 1;
+    if (!xch) {
+        fprintf(stderr, "xc_interface_open() failed\n");
+        return 1;
+    }
 
     rv = build(xch, argc, argv);
 
@@ -110,13 +167,18 @@ int main(int argc, char** argv)
     xs_daemon_close(xsh);
 
     fd = creat("/var/run/xenstored.pid", 0666);
-    if (fd < 0)
+    if (fd < 0) {
+        fprintf(stderr, "Creating /var/run/xenstored.pid failed\n");
         return 3;
+    }
     rv = snprintf(buf, 16, "domid:%d\n", domid);
     rv = write(fd, buf, rv);
     close(fd);
-    if (rv < 0)
+    if (rv < 0) {
+        fprintf(stderr,
+            "Writing domid to /var/run/xenstored.pid failed\n");
         return 3;
+    }
 
     return 0;
 }
-- 
2.6.2