diff --git a/linux-2.6-xen-sparse/arch/xen/kernel/reboot.c b/linux-2.6-xen-sparse/arch/xen/kernel/reboot.c
index 89c2005450..81f0f10c21 100644
--- a/linux-2.6-xen-sparse/arch/xen/kernel/reboot.c
+++ b/linux-2.6-xen-sparse/arch/xen/kernel/reboot.c
@@ -188,7 +188,7 @@ static int __do_suspend(void *ignore)
 	xenbus_resume();
 
 #ifdef CONFIG_SMP
-	for_each_present_cpu(i)
+	for_each_cpu(i)
 		vcpu_prepare(i);
 
  out_reenable_cpus:
diff --git a/linux-2.6-xen-sparse/arch/xen/kernel/smpboot.c b/linux-2.6-xen-sparse/arch/xen/kernel/smpboot.c
index 31ea6473f1..66bb891ec6 100644
--- a/linux-2.6-xen-sparse/arch/xen/kernel/smpboot.c
+++ b/linux-2.6-xen-sparse/arch/xen/kernel/smpboot.c
@@ -277,6 +277,18 @@ void __devinit smp_prepare_boot_cpu(void)
 
 #ifdef CONFIG_HOTPLUG_CPU
 
+/*
+ * Initialize cpu_present_map late to skip SMP boot code in init/main.c.
+ * But do it early enough to catch critical for_each_present_cpu() loops
+ * in i386-specific code.
+ */
+static int __init initialize_cpu_present_map(void)
+{
+	cpu_present_map = cpu_possible_map;
+	return 0;
+}
+core_initcall(initialize_cpu_present_map);
+
 static void vcpu_hotplug(unsigned int cpu)
 {
 	int err;
@@ -293,7 +305,6 @@ static void vcpu_hotplug(unsigned int cpu)
 	}
 
 	if (strcmp(state, "online") == 0) {
-		cpu_set(cpu, cpu_present_map);
 		(void)cpu_up(cpu);
 	} else if (strcmp(state, "offline") == 0) {
 		(void)cpu_down(cpu);
diff --git a/tools/python/xen/xend/XendDomainInfo.py b/tools/python/xen/xend/XendDomainInfo.py
index 886d5c4f0f..3b50fc9be6 100644
--- a/tools/python/xen/xend/XendDomainInfo.py
+++ b/tools/python/xen/xend/XendDomainInfo.py
@@ -437,10 +437,18 @@ class XendDomainInfo:
             defaultInfo('on_crash',     lambda: "restart")
             defaultInfo('cpu',          lambda: None)
             defaultInfo('cpu_weight',   lambda: 1.0)
-            defaultInfo('vcpus',        lambda: int(1))
 
-            self.info['vcpus'] = int(self.info['vcpus'])
+            # some domains don't have a config file (e.g. dom0 )
+            # to set number of vcpus so we derive available cpus
+            # from max_vcpu_id which is present for running domains.
+            if not self.infoIsSet('vcpus') and self.infoIsSet('max_vcpu_id'):
+                avail = int(self.info['max_vcpu_id'])+1
+            else:
+                avail = int(1)
 
+            defaultInfo('vcpus',        lambda: avail)
+            defaultInfo('online_vcpus', lambda: self.info['vcpus'])
+            defaultInfo('max_vcpu_id',  lambda: self.info['vcpus']-1)
             defaultInfo('vcpu_avail',   lambda: (1 << self.info['vcpus']) - 1)
 
             defaultInfo('memory',       lambda: 0)
@@ -927,6 +935,7 @@ class XendDomainInfo:
         if self.infoIsSet('cpu_time'):
             sxpr.append(['cpu_time', self.info['cpu_time']/1e9])
         sxpr.append(['vcpus', self.info['vcpus']])
+        sxpr.append(['online_vcpus', self.info['online_vcpus']])
             
         if self.infoIsSet('start_time'):
             up_time =  time.time() - self.info['start_time']
@@ -943,16 +952,13 @@ class XendDomainInfo:
 
     def getVCPUInfo(self):
         try:
-            def filter_cpumap(map, max):
-                return filter(lambda x: x >= 0, map[0:max])
-
             # We include the domain name and ID, to help xm.
             sxpr = ['domain',
                     ['domid',      self.domid],
                     ['name',       self.info['name']],
-                    ['vcpu_count', self.info['vcpus']]]
+                    ['vcpu_count', self.info['online_vcpus']]]
 
-            for i in range(0, self.info['vcpus']):
+            for i in range(0, self.info['max_vcpu_id']+1):
                 info = xc.vcpu_getinfo(self.domid, i)
 
                 sxpr.append(['vcpu',
@@ -962,8 +968,7 @@ class XendDomainInfo:
                              ['running',  info['running']],
                              ['cpu_time', info['cpu_time'] / 1e9],
                              ['cpu',      info['cpu']],
-                             ['cpumap',   filter_cpumap(info['cpumap'],
-                                                        self.info['vcpus'])]])
+                             ['cpumap',   info['cpumap']]])
 
             return sxpr
 
diff --git a/tools/python/xen/xm/main.py b/tools/python/xen/xm/main.py
index ec4bf16d3a..fc0521fe3f 100644
--- a/tools/python/xen/xm/main.py
+++ b/tools/python/xen/xm/main.py
@@ -260,13 +260,13 @@ def parse_doms_info(info):
         return t(sxp.child_value(info, n, d))
     
     return {
-        'dom'      : get_info('domid',    int,   -1),
-        'name'     : get_info('name',     str,   '??'),
-        'mem'      : get_info('memory',   int,   0),
-        'vcpus'    : get_info('vcpus',    int,   0),
-        'state'    : get_info('state',    str,   '??'),
-        'cpu_time' : get_info('cpu_time', float, 0),
-        'ssidref'  : get_info('ssidref',  int,   0),
+        'dom'      : get_info('domid',        int,   -1),
+        'name'     : get_info('name',         str,   '??'),
+        'mem'      : get_info('memory',       int,   0),
+        'vcpus'    : get_info('online_vcpus', int,   0),
+        'state'    : get_info('state',        str,   '??'),
+        'cpu_time' : get_info('cpu_time',     float, 0),
+        'ssidref'  : get_info('ssidref',      int,   0),
         }