xl: guest reboot cleanups

diff -r 850af6e1985e -r d12ad3958ca7 tools/libxl/libxl_dom.c
@@ -81,6 +81,7 @@ libxl_scheduler libxl__domain_scheduler(
     if (cpupool < 0)
         return sched;
 
+    libxl_cpupoolinfo_init(&poolinfo);
     rc = libxl_cpupool_info(CTX, &poolinfo, cpupool);
     if (rc < 0)
         goto out;

diff -r d12ad3958ca7 -r 763756d2590c tools/libxl/libxl_dom.c
@@ -73,7 +73,7 @@ int libxl__domain_cpupool(libxl__gc *gc,
 
 libxl_scheduler libxl__domain_scheduler(libxl__gc *gc, uint32_t domid)
 {
-    uint32_t cpupool = libxl__domain_cpupool(gc, domid);
+    int cpupool = libxl__domain_cpupool(gc, domid);
     libxl_cpupoolinfo poolinfo;
     libxl_scheduler sched = LIBXL_SCHEDULER_UNKNOWN;
     int rc;

diff -r 763756d2590c -r 426b2f7429a7 tools/libxl/libxl.c
@@ -571,16 +571,27 @@ static int cpupool_info(libxl__gc *gc,
 
     xcinfo = xc_cpupool_getinfo(CTX->xch, poolid);
     if (xcinfo == NULL)
+    {
+        LOGE(ERROR, "failed to get info for cpupool%d\n", poolid);
         return ERROR_FAIL;
+    }
 
     if (exact && xcinfo->cpupool_id != poolid)
+    {
+        LOG(ERROR, "got info for cpupool%d, wanted cpupool%d\n",
+            xcinfo->cpupool_id, poolid);
         goto out;
+    }
 
     info->poolid = xcinfo->cpupool_id;
     info->sched = xcinfo->sched_id;
     info->n_dom = xcinfo->n_dom;
-    if (libxl_cpumap_alloc(CTX, &info->cpumap, 0))
+    rc = libxl_cpumap_alloc(CTX, &info->cpumap, 0);
+    if (rc)
+    {
+        LOG(ERROR, "unable to allocate cpumap %d\n", rc);
         goto out;
+    }
     memcpy(info->cpumap.map, xcinfo->cpumap, info->cpumap.size);
 
     rc = 0;

diff -r 763756d2590c -r 426b2f7429a7 tools/libxl/libxl_dom.c
@@ -64,10 +64,15 @@ int libxl__domain_cpupool(libxl__gc *gc,
 
     ret = xc_domain_getinfolist(CTX->xch, domid, 1, &info);
     if (ret != 1)
+    {
+        LOGE(ERROR, "getinfolist failed %d\n", ret);
         return ERROR_FAIL;
+    }
     if (info.domain != domid)
+    {
+        LOGE(ERROR, "got info for dom%d, wanted dom%d\n", info.domain, domid);
         return ERROR_FAIL;
-
+    }
     return info.cpupool;
 }

diff -r 426b2f7429a7 -r 77993401a44f tools/libxl/xl_cmdimpl.c
@@ -68,7 +68,8 @@ libxl_ctx *ctx;
 xlchild children[child_max];
 
 /* when we operate on a domain, it is this one: */
-static uint32_t domid;
+#define INVALID_DOMID ~0
+static uint32_t domid = INVALID_DOMID;
 static const char *common_domname;
 static int fd_lock = -1;
 

@@ -1396,6 +1397,7 @@ static int handle_domain_death(uint32_t 
     case LIBXL_ACTION_ON_SHUTDOWN_DESTROY:
         LOG("Domain %d needs to be cleaned up: destroying the domain", domid);
         libxl_domain_destroy(ctx, domid);
+        domid = INVALID_DOMID;
         break;
 
     case LIBXL_ACTION_ON_SHUTDOWN_COREDUMP_DESTROY:

@@ -1458,6 +1460,12 @@ static int preserve_domain(uint32_t domi
     LOG("Preserving domain %d %s with suffix%s", domid, d_config->c_info.name, stime);
     rc = libxl_domain_preserve(ctx, domid, &d_config->c_info, stime, new_uuid);
 
+    /*
+     * Although domid still exists it is no longer the one we are concerned
+     * with.
+     */
+    domid = INVALID_DOMID;
+
     return rc == 0 ? 1 : 0;
 }
 

@@ -1745,7 +1753,7 @@ static int create_domain(struct domain_c
         goto out;
 
 start:
-    domid = -1;
+    assert(domid == INVALID_DOMID);
 
     rc = acquire_lock();
     if (rc < 0)

@@ -1994,8 +2002,10 @@ start:
 
 error_out:
     release_lock();
-    if (libxl_domid_valid_guest(domid))
+    if (libxl_domid_valid_guest(domid)) {
         libxl_domain_destroy(ctx, domid);
+        domid = INVALID_DOMID;
+    }
 
 out:
     if (logfile != 2)