New XEN_DOMCTL_set_target

Stubdomains (and probably other domain disagregation elements too)
need to be able to tinker with another domain.  This adds IS_PRIV_FOR
that extends IS_PRIV by allowing domains to have privileges over a
given "target" domain.  XEN_DOMCTL_set_target permits to set this
"target". A new 'target' configuration option makes the domain builder
use it.

Signed-off-by: Samuel Thibault <samuel.thibault@eu.citrix.com>

25 files changed, 426 insertions, 186 deletions

diff --git a/tools/libxc/xc_domain.c b/tools/libxc/xc_domain.c
index 8be00d1ab6..f75955c577 100644
--- a/tools/libxc/xc_domain.c
+++ b/tools/libxc/xc_domain.c
@@ -875,6 +875,20 @@ int xc_domain_ioport_mapping(
     return do_domctl(xc_handle, &domctl);
 }
 
+int xc_domain_set_target(
+    int xc_handle,
+    uint32_t domid,
+    uint32_t target)
+{
+    DECLARE_DOMCTL;
+
+    domctl.cmd = XEN_DOMCTL_set_target;
+    domctl.domain = domid;
+    domctl.u.set_target.target = target;
+
+    return do_domctl(xc_handle, &domctl);
+}
+
 /*
  * Local variables:
  * mode: C
diff --git a/tools/libxc/xenctrl.h b/tools/libxc/xenctrl.h
index d9c6bace54..f6778dd946 100644
--- a/tools/libxc/xenctrl.h
+++ b/tools/libxc/xenctrl.h
@@ -952,4 +952,9 @@ int xc_domain_bind_pt_isa_irq(int xc_handle,
                               uint32_t domid,
                               uint8_t machine_irq);
 
+/* Set the target domain */
+int xc_domain_set_target(int xc_handle,
+                         uint32_t domid,
+                         uint32_t target);
+
 #endif /* XENCTRL_H */
diff --git a/tools/python/xen/lowlevel/xc/xc.c b/tools/python/xen/lowlevel/xc/xc.c
index 1f1421e487..29a1bc0fd2 100644
--- a/tools/python/xen/lowlevel/xc/xc.c
+++ b/tools/python/xen/lowlevel/xc/xc.c
@@ -96,17 +96,17 @@ static PyObject *pyxc_domain_create(XcObject *self,
                                     PyObject *args,
                                     PyObject *kwds)
 {
-    uint32_t dom = 0, ssidref = 0, flags = 0;
+    uint32_t dom = 0, ssidref = 0, flags = 0, target = 0;
     int      ret, i, hvm = 0;
     PyObject *pyhandle = NULL;
     xen_domain_handle_t handle = { 
         0xde, 0xad, 0xbe, 0xef, 0xde, 0xad, 0xbe, 0xef,
         0xde, 0xad, 0xbe, 0xef, 0xde, 0xad, 0xbe, 0xef };
 
-    static char *kwd_list[] = { "domid", "ssidref", "handle", "hvm", NULL };
+    static char *kwd_list[] = { "domid", "ssidref", "handle", "hvm", "target", NULL };
 
-    if ( !PyArg_ParseTupleAndKeywords(args, kwds, "|iiOi", kwd_list,
-                                      &dom, &ssidref, &pyhandle, &hvm))
+    if ( !PyArg_ParseTupleAndKeywords(args, kwds, "|iiOii", kwd_list,
+				      &dom, &ssidref, &pyhandle, &hvm, &target))
         return NULL;
 
     if ( pyhandle != NULL )
@@ -131,6 +131,11 @@ static PyObject *pyxc_domain_create(XcObject *self,
                                  handle, flags, &dom)) < 0 )
         return pyxc_error_to_exception();
 
+    if ( target )
+        if ( (ret = xc_domain_set_target(self->xc_handle, dom, target)) < 0 )
+            return pyxc_error_to_exception();
+
+
     return PyInt_FromLong(dom);
 
 out_exception:
diff --git a/tools/python/xen/xend/XendConfig.py b/tools/python/xen/xend/XendConfig.py
index 0e970b6293..67803517eb 100644
--- a/tools/python/xen/xend/XendConfig.py
+++ b/tools/python/xen/xend/XendConfig.py
@@ -170,6 +170,7 @@ XENAPI_CFG_TYPES = {
     'platform': dict,
     'tools_version': dict,
     'other_config': dict,
+    'target': int,
     'security_label': str,
     'pci': str,
 }
@@ -336,7 +337,8 @@ class XendConfig(dict):
             'vbd_refs': [],
             'vtpm_refs': [],
             'other_config': {},
-            'platform': {}
+            'platform': {},
+            'target': 0,
         }
         
         return defaults
@@ -1585,6 +1587,9 @@ class XendConfig(dict):
     def is_hvm(self):
         return self['HVM_boot_policy'] != ''
 
+    def target(self):
+	return self['target']
+
     def image_type(self):
         stored_type = self['platform'].get('image_type')
         return stored_type or (self.is_hvm() and 'hvm' or 'linux')
diff --git a/tools/python/xen/xend/XendDomainInfo.py b/tools/python/xen/xend/XendDomainInfo.py
index 052258ec55..38d276748a 100644
--- a/tools/python/xen/xend/XendDomainInfo.py
+++ b/tools/python/xen/xend/XendDomainInfo.py
@@ -1640,7 +1640,8 @@ class XendDomainInfo:
                 domid = 0,
                 ssidref = ssidref,
                 handle = uuid.fromString(self.info['uuid']),
-                hvm = int(hvm))
+                hvm = int(hvm),
+                target = self.info.target())
         except Exception, e:
             # may get here if due to ACM the operation is not permitted
             if security.on():
diff --git a/tools/python/xen/xm/create.py b/tools/python/xen/xm/create.py
index 440b7d4fe9..b201c548db 100644
--- a/tools/python/xen/xm/create.py
+++ b/tools/python/xen/xm/create.py
@@ -521,6 +521,10 @@ gopts.var('on_xend_stop', val='ignore|shutdown|suspend',
           - suspend:        Domain is suspended;
           """)
 
+gopts.var('target', val='TARGET',
+          fn=set_int, default=0,
+          use="Set domain target.")
+
 def err(msg):
     """Print an error to stderr and exit.
     """
@@ -748,7 +752,7 @@ def make_config(vals):
     map(add_conf, ['name', 'memory', 'maxmem', 'shadow_memory',
                    'restart', 'on_poweroff',
                    'on_reboot', 'on_crash', 'vcpus', 'vcpu_avail', 'features',
-                   'on_xend_start', 'on_xend_stop'])
+                   'on_xend_start', 'on_xend_stop', 'target'])
 
     if vals.uuid is not None:
         config.append(['uuid', vals.uuid])
diff --git a/xen/arch/ia64/vmx/vmx_hypercall.c b/xen/arch/ia64/vmx/vmx_hypercall.c
index 5f79cb59d1..b9c5b52568 100644
--- a/xen/arch/ia64/vmx/vmx_hypercall.c
+++ b/xen/arch/ia64/vmx/vmx_hypercall.c
@@ -47,9 +47,6 @@ static int hvmop_set_isa_irq_level(
     if ( copy_from_guest(&op, uop, 1) )
         return -EFAULT;
 
-    if ( !IS_PRIV(current->domain) )
-        return -EPERM;
-
     if ( op.isa_irq > 15 )
         return -EINVAL;
 
@@ -57,6 +54,10 @@ static int hvmop_set_isa_irq_level(
     if ( d == NULL )
         return -ESRCH;
 
+    rc = -EPERM;
+    if ( !IS_PRIV_FOR(current->domain, d) )
+        goto out;
+
     rc = -EINVAL;
     if ( !is_hvm_domain(d) )
         goto out;
@@ -79,9 +80,6 @@ static int hvmop_set_pci_intx_level(
     if ( copy_from_guest(&op, uop, 1) )
         return -EFAULT;
 
-    if ( !IS_PRIV(current->domain) )
-        return -EPERM;
-
     if ( (op.domain > 0) || (op.bus > 0) || (op.device > 31) || (op.intx > 3) )
         return -EINVAL;
 
@@ -89,6 +87,10 @@ static int hvmop_set_pci_intx_level(
     if ( d == NULL )
         return -ESRCH;
 
+    rc = -EPERM;
+    if ( !IS_PRIV_FOR(current->domain, d) )
+        goto out;
+
     rc = -EINVAL;
     if ( !is_hvm_domain(d) )
         goto out;
@@ -124,13 +126,15 @@ do_hvm_op(unsigned long op, XEN_GUEST_HANDLE(void) arg)
         if (a.domid == DOMID_SELF) {
             d = rcu_lock_current_domain();
         }
-        else if (IS_PRIV(current->domain)) {
+        else {
             d = rcu_lock_domain_by_id(a.domid);
             if (d == NULL)
                 return -ESRCH;
+            if (!IS_PRIV_FOR(current->domain, d)) {
+                rcu_unlock_domain(d);
+                return -EPERM;
+            }
         }
-        else
-            return -EPERM;
 
         if (op == HVMOP_set_param) {
             struct vmx_ioreq_page *iorp;
diff --git a/xen/arch/ia64/xen/dom0_ops.c b/xen/arch/ia64/xen/dom0_ops.c
index 85f8eaf7ee..525ed28d54 100644
--- a/xen/arch/ia64/xen/dom0_ops.c
+++ b/xen/arch/ia64/xen/dom0_ops.c
@@ -37,9 +37,6 @@ long arch_do_domctl(xen_domctl_t *op, XEN_GUEST_HANDLE(xen_domctl_t) u_domctl)
 {
     long ret = 0;
 
-    if ( !IS_PRIV(current->domain) )
-        return -EPERM;
-
     switch ( op->cmd )
     {
     case XEN_DOMCTL_getmemlist:
@@ -54,6 +51,13 @@ long arch_do_domctl(xen_domctl_t *op, XEN_GUEST_HANDLE(xen_domctl_t) u_domctl)
             ret = -EINVAL;
             break;
         }
+
+        if ( !IS_PRIV_FOR(current->domain, d) ) {
+            ret = -EPERM;
+            rcu_unlock_domain(d);
+            break;
+        }
+
         for (i = 0 ; i < nr_pages ; i++) {
             pte_t *pte;
 
@@ -87,6 +91,12 @@ long arch_do_domctl(xen_domctl_t *op, XEN_GUEST_HANDLE(xen_domctl_t) u_domctl)
             break;
         }
 
+        if ( !IS_PRIV_FOR(current->domain, d) ) {
+            ret = -EPERM;
+            rcu_unlock_domain(d);
+            break;
+        }
+
         if (ds->flags & XEN_DOMAINSETUP_query) {
             /* Set flags.  */
             if (is_hvm_domain(d))
@@ -153,6 +163,12 @@ long arch_do_domctl(xen_domctl_t *op, XEN_GUEST_HANDLE(xen_domctl_t) u_domctl)
         d = rcu_lock_domain_by_id(op->domain);
         if ( d != NULL )
         {
+            if ( !IS_PRIV_FOR(current->domain, d) ) {
+                ret = -EPERM;
+                rcu_unlock_domain(d);
+                break;
+            }
+
             ret = shadow_mode_control(d, &op->u.shadow_op);
             rcu_unlock_domain(d);
             if (copy_to_guest(u_domctl, op, 1))
@@ -173,6 +189,12 @@ long arch_do_domctl(xen_domctl_t *op, XEN_GUEST_HANDLE(xen_domctl_t) u_domctl)
         if (unlikely(d == NULL))
             break;
 
+        if ( !IS_PRIV_FOR(current->domain, d) ) {
+            ret = -EPERM;
+            rcu_unlock_domain(d);
+            break;
+        }
+
         if (np == 0)
             ret = 0;
         else {
@@ -196,6 +218,11 @@ long arch_do_domctl(xen_domctl_t *op, XEN_GUEST_HANDLE(xen_domctl_t) u_domctl)
         if ( d == NULL )
             break;
 
+        ret = -EPERM;
+        if ( !IS_PRIV_FOR(current->domain, d) ) {
+            goto sendtrigger_out;
+        }
+
         ret = -EINVAL;
         if ( op->u.sendtrigger.vcpu >= MAX_VIRT_CPUS )
             goto sendtrigger_out;
@@ -239,6 +266,10 @@ long arch_do_domctl(xen_domctl_t *op, XEN_GUEST_HANDLE(xen_domctl_t) u_domctl)
         if (d == NULL)
             break;
 
+        ret = -EPERM;
+        if ( !IS_PRIV_FOR(current->domain, d) )
+            goto sethvmcontext_out;
+
 #ifdef CONFIG_X86
         ret = xsm_hvmcontext(d, op->cmd);
         if (ret)
@@ -280,6 +311,10 @@ long arch_do_domctl(xen_domctl_t *op, XEN_GUEST_HANDLE(xen_domctl_t) u_domctl)
         if (d == NULL)
             break;
 
+        ret = -EPERM;
+        if ( !IS_PRIV_FOR(current->domain, d) )
+            goto gethvmcontext_out;
+
 #ifdef CONFIG_X86
         ret = xsm_hvmcontext(d, op->cmd);
         if (ret)
@@ -341,7 +376,10 @@ long arch_do_domctl(xen_domctl_t *op, XEN_GUEST_HANDLE(xen_domctl_t) u_domctl)
             break;
         }
 
-        ret = domain_opt_feature(d, optf);
+        ret = -EPERM;
+        if ( IS_PRIV_FOR(current->domain, d) )
+            ret = domain_opt_feature(d, optf);
+
         rcu_unlock_domain(d);
     }
     break;
diff --git a/xen/arch/ia64/xen/hypercall.c b/xen/arch/ia64/xen/hypercall.c
index c2879f7c9a..9ef8ca8de1 100644
--- a/xen/arch/ia64/xen/hypercall.c
+++ b/xen/arch/ia64/xen/hypercall.c
@@ -500,13 +500,15 @@ do_ia64_debug_op(unsigned long cmd, unsigned long domain,
     struct domain *d;
     long ret = 0;
 
-    if (!IS_PRIV(current->domain))
-        return -EPERM;
     if (copy_from_guest(op, u_debug_op, 1))
         return -EFAULT;
     d = rcu_lock_domain_by_id(domain);
     if (d == NULL)
         return -ESRCH;
+    if (!IS_PRIV_FOR(current->domain, d)) {
+        ret = -EPERM;
+        goto out;
+    }
 
     switch (cmd) {
     case XEN_IA64_DEBUG_OP_SET_FLAGS:
@@ -520,6 +522,7 @@ do_ia64_debug_op(unsigned long cmd, unsigned long domain,
     default:
         ret = -ENOSYS;
     }
+out:
     rcu_unlock_domain(d);
     return ret;
 }
diff --git a/xen/arch/ia64/xen/mm.c b/xen/arch/ia64/xen/mm.c
index 9c80393372..782d12ae97 100644
--- a/xen/arch/ia64/xen/mm.c
+++ b/xen/arch/ia64/xen/mm.c
@@ -2787,10 +2787,14 @@ arch_memory_op(int op, XEN_GUEST_HANDLE(void) arg)
 
         if (xatp.domid == DOMID_SELF)
             d = rcu_lock_current_domain();
-        else if (!IS_PRIV(current->domain))
-            return -EPERM;
-        else if ((d = rcu_lock_domain_by_id(xatp.domid)) == NULL)
-            return -ESRCH;
+        else {
+            if ((d = rcu_lock_domain_by_id(xatp.domid)) == NULL)
+                return -ESRCH;
+            if (!IS_PRIV_FOR(current->domain,d)) {
+                rcu_lock_domain(d);
+                return -EPERM;
+            }
+        }
 
         /* This hypercall is used for VT-i domain only */
         if (!VMX_DOMAIN(d->vcpu[0])) {
diff --git a/xen/arch/ia64/xen/xensetup.c b/xen/arch/ia64/xen/xensetup.c
index ede498abab..fb806af049 100644
--- a/xen/arch/ia64/xen/xensetup.c
+++ b/xen/arch/ia64/xen/xensetup.c
@@ -642,6 +642,7 @@ printk("num_online_cpus=%d, max_cpus=%d\n",num_online_cpus(),max_cpus);
         panic("Cannot allocate dom0 vcpu 0\n");
 
     dom0->is_privileged = 1;
+    dom0->target = NULL;
 
     /*
      * We're going to setup domain0 using the module(s) that we stashed safely
diff --git a/xen/arch/powerpc/setup.c b/xen/arch/powerpc/setup.c
index 6abf10cf17..7f2f5d2572 100644
--- a/xen/arch/powerpc/setup.c
+++ b/xen/arch/powerpc/setup.c
@@ -375,6 +375,7 @@ static void __init __start_xen(void)
     dom0->vcpu[0]->cpu_affinity = cpumask_of_cpu(0);
 
     dom0->is_privileged = 1;
+    dom0->target = NULL;
 
     /* scrub_heap_pages() requires IRQs enabled, and we're post IRQ setup... */
     local_irq_enable();
diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index c812982140..9f88fd0cdd 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -1740,9 +1740,6 @@ static int hvmop_set_pci_intx_level(
     if ( copy_from_guest(&op, uop, 1) )
         return -EFAULT;
 
-    if ( !IS_PRIV(current->domain) )
-        return -EPERM;
-
     if ( (op.domain > 0) || (op.bus > 0) || (op.device > 31) || (op.intx > 3) )
         return -EINVAL;
 
@@ -1750,6 +1747,10 @@ static int hvmop_set_pci_intx_level(
     if ( d == NULL )
         return -ESRCH;
 
+    rc = -EPERM;
+    if ( !IS_PRIV_FOR(current->domain, d) )
+        goto out;
+
     rc = -EINVAL;
     if ( !is_hvm_domain(d) )
         goto out;
@@ -1787,9 +1788,6 @@ static int hvmop_set_isa_irq_level(
     if ( copy_from_guest(&op, uop, 1) )
         return -EFAULT;
 
-    if ( !IS_PRIV(current->domain) )
-        return -EPERM;
-
     if ( op.isa_irq > 15 )
         return -EINVAL;
 
@@ -1797,6 +1795,10 @@ static int hvmop_set_isa_irq_level(
     if ( d == NULL )
         return -ESRCH;
 
+    rc = -EPERM;
+    if ( !IS_PRIV_FOR(current->domain, d) )
+        goto out;
+
     rc = -EINVAL;
     if ( !is_hvm_domain(d) )
         goto out;
@@ -1834,9 +1836,6 @@ static int hvmop_set_pci_link_route(
     if ( copy_from_guest(&op, uop, 1) )
         return -EFAULT;
 
-    if ( !IS_PRIV(current->domain) )
-        return -EPERM;
-
     if ( (op.link > 3) || (op.isa_irq > 15) )
         return -EINVAL;
 
@@ -1844,6 +1843,10 @@ static int hvmop_set_pci_link_route(
     if ( d == NULL )
         return -ESRCH;
 
+    rc = -EPERM;
+    if ( !IS_PRIV_FOR(current->domain, d) )
+        goto out;
+
     rc = -EINVAL;
     if ( !is_hvm_domain(d) )
         goto out;
@@ -1921,13 +1924,16 @@ long do_hvm_op(unsigned long op, XEN_GUEST_HANDLE(void) arg)
 
         if ( a.domid == DOMID_SELF )
             d = rcu_lock_current_domain();
-        else if ( IS_PRIV(current->domain) )
+        else {
             d = rcu_lock_domain_by_id(a.domid);
-        else
-            return -EPERM;
+            if ( d == NULL )
+                return -ESRCH;
+            if ( !IS_PRIV_FOR(current->domain, d) ) {
+                rc = -EPERM;
+                goto param_fail;
+            }
+        }
 
-        if ( d == NULL )
-            return -ESRCH;
 
         rc = -EINVAL;
         if ( !is_hvm_domain(d) )
diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
index baea82118b..efd077ae6d 100644
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -2056,38 +2056,35 @@ static int set_foreigndom(domid_t domid)
         MEM_LOG("Cannot mix foreign mappings with translated domains");
         okay = 0;
     }
-    else if ( !IS_PRIV(d) )
+    else switch ( domid )
     {
-        switch ( domid )
-        {
-        case DOMID_IO:
-            info->foreign = rcu_lock_domain(dom_io);
-            break;
-        default:
+    case DOMID_IO:
+        info->foreign = rcu_lock_domain(dom_io);
+        break;
+    case DOMID_XEN:
+        if (!IS_PRIV(d)) {
             MEM_LOG("Cannot set foreign dom");
             okay = 0;
             break;
         }
-    }
-    else
-    {
-        info->foreign = e = rcu_lock_domain_by_id(domid);
+        info->foreign = rcu_lock_domain(dom_xen);
+        break;
+    default:
+        e = rcu_lock_domain_by_id(domid);
         if ( e == NULL )
         {
-            switch ( domid )
-            {
-            case DOMID_XEN:
-                info->foreign = rcu_lock_domain(dom_xen);
-                break;
-            case DOMID_IO:
-                info->foreign = rcu_lock_domain(dom_io);
-                break;
-            default:
-                MEM_LOG("Unknown domain '%u'", domid);
-                okay = 0;
-                break;
-            }
+            MEM_LOG("Unknown domain '%u'", domid);
+            okay = 0;
+            break;
+        }
+        if (!IS_PRIV_FOR(d, e)) {
+            MEM_LOG("Cannot set foreign dom");
+            okay = 0;
+            rcu_unlock_domain(e);
+            break;
         }
+        info->foreign = e;
+        break;
     }
 
  out:
@@ -3043,9 +3040,6 @@ int do_update_va_mapping_otherdomain(unsigned long va, u64 val64,
 {
     int rc;
 
-    if ( unlikely(!IS_PRIV(current->domain)) )
-        return -EPERM;
-
     if ( !set_foreigndom(domid) )
         return -ESRCH;
 
@@ -3222,10 +3216,15 @@ long arch_memory_op(int op, XEN_GUEST_HANDLE(void) arg)
 
         if ( xatp.domid == DOMID_SELF )
             d = rcu_lock_current_domain();
-        else if ( !IS_PRIV(current->domain) )
-            return -EPERM;
-        else if ( (d = rcu_lock_domain_by_id(xatp.domid)) == NULL )
-            return -ESRCH;
+        else {
+            d = rcu_lock_domain_by_id(xatp.domid);
+            if ( d == NULL )
+                return -ESRCH;
+            if ( !IS_PRIV_FOR(current->domain, d) ) {
+                rcu_unlock_domain(d);
+                return -EPERM;
+            }
+        }
 
         if ( xsm_add_to_physmap(current->domain, d) )
         {
@@ -3313,10 +3312,15 @@ long arch_memory_op(int op, XEN_GUEST_HANDLE(void) arg)
 
         if ( fmap.domid == DOMID_SELF )
             d = rcu_lock_current_domain();
-        else if ( !IS_PRIV(current->domain) )
-            return -EPERM;
-        else if ( (d = rcu_lock_domain_by_id(fmap.domid)) == NULL )
-            return -ESRCH;
+        else {
+            d = rcu_lock_domain_by_id(fmap.domid);
+            if ( d == NULL )
+                return -ESRCH;
+            if ( !IS_PRIV_FOR(current->domain, d) ) {
+                rcu_unlock_domain(d);
+                return -EPERM;
+            }
+        }
 
         rc = xsm_domain_memory_map(d);
         if ( rc )
diff --git a/xen/arch/x86/mm/shadow/multi.c b/xen/arch/x86/mm/shadow/multi.c
index 1c4e7fad70..5a460d9de2 100644
--- a/xen/arch/x86/mm/shadow/multi.c
+++ b/xen/arch/x86/mm/shadow/multi.c
@@ -993,11 +993,11 @@ shadow_get_page_from_l1e(shadow_l1e_t sl1e, struct domain *d)
     // not own, we let it succeed anyway.
     //
     if ( unlikely(!res) &&
-         IS_PRIV(d) &&
          !shadow_mode_translate(d) &&
          mfn_valid(mfn = shadow_l1e_get_mfn(sl1e)) &&
          (owner = page_get_owner(mfn_to_page(mfn))) &&
-         (d != owner) )
+         (d != owner) &&
+         IS_PRIV_FOR(d, owner))
     {
         res = get_page_from_l1e(sl1e, owner);
         SHADOW_PRINTK("privileged domain %d installs map of mfn %05lx "
diff --git a/xen/arch/x86/setup.c b/xen/arch/x86/setup.c
index 095ee91116..031feb12a2 100644
--- a/xen/arch/x86/setup.c
+++ b/xen/arch/x86/setup.c
@@ -959,6 +959,7 @@ void __init __start_xen(unsigned long mbi_p)
         panic("Error creating domain 0\n");
 
     dom0->is_privileged = 1;
+    dom0->target = NULL;
 
     /* Grab the DOM0 command line. */
     cmdline = (char *)(mod[0].string ? __va(mod[0].string) : NULL);
diff --git a/xen/common/domain.c b/xen/common/domain.c
index 6c26363c65..a888d88d79 100644
--- a/xen/common/domain.c
+++ b/xen/common/domain.c
@@ -502,6 +502,9 @@ static void complete_domain_destroy(struct rcu_head *head)
         if ( (v = d->vcpu[i]) != NULL )
             free_vcpu_struct(v);
 
+    if (d->target)
+        put_domain(d->target);
+
     free_domain(d);
 
     send_guest_global_virq(dom0, VIRQ_DOM_EXC);
diff --git a/xen/common/domctl.c b/xen/common/domctl.c
index 3f87a73c84..83d191d93a 100644
--- a/xen/common/domctl.c
+++ b/xen/common/domctl.c
@@ -182,9 +182,6 @@ long do_domctl(XEN_GUEST_HANDLE(xen_domctl_t) u_domctl)
     struct xen_domctl curop, *op = &curop;
     static DEFINE_SPINLOCK(domctl_lock);
 
-    if ( !IS_PRIV(current->domain) )
-        return -EPERM;
-
     if ( copy_from_guest(op, u_domctl, 1) )
         return -EFAULT;
 
@@ -207,6 +204,10 @@ long do_domctl(XEN_GUEST_HANDLE(xen_domctl_t) u_domctl)
         if ( d == NULL )
             break;
 
+        ret = -EPERM;
+        if ( !IS_PRIV_FOR(current->domain, d) )
+            goto svc_out;
+
         ret = xsm_setvcpucontext(d);
         if ( ret )
             goto svc_out;
@@ -258,6 +259,10 @@ long do_domctl(XEN_GUEST_HANDLE(xen_domctl_t) u_domctl)
         ret = -ESRCH;
         if ( d != NULL )
         {
+            ret = -EPERM;
+            if ( !IS_PRIV_FOR(current->domain, d) )
+                goto pausedomain_out;
+
             ret = xsm_pausedomain(d);
             if ( ret )
                 goto pausedomain_out;
@@ -282,16 +287,18 @@ long do_domctl(XEN_GUEST_HANDLE(xen_domctl_t) u_domctl)
         if ( d == NULL )
             break;
 
+        ret = -EPERM;
+        if ( !IS_PRIV_FOR(current->domain, d) )
+            goto unpausedomain_out;
+
         ret = xsm_unpausedomain(d);
         if ( ret )
-        {
-            rcu_unlock_domain(d);
-            break;
-        }
+            goto unpausedomain_out;
 
         domain_unpause_by_systemcontroller(d);
-        rcu_unlock_domain(d);
         ret = 0;
+unpausedomain_out:
+        rcu_unlock_domain(d);
     }
     break;
 
@@ -303,16 +310,18 @@ long do_domctl(XEN_GUEST_HANDLE(xen_domctl_t) u_domctl)
         if ( d == NULL )
             break;
 
+        ret = -EPERM;
+        if ( !IS_PRIV_FOR(current->domain, d) )
+            goto resumedomain_out;
+
         ret = xsm_resumedomain(d);
         if ( ret )
-        {
-            rcu_unlock_domain(d);
-            break;
-        }
+            goto resumedomain_out;
 
         domain_resume(d);
-        rcu_unlock_domain(d);
         ret = 0;
+resumedomain_out:
+        rcu_unlock_domain(d);
     }
     break;
 
@@ -323,6 +332,10 @@ long do_domctl(XEN_GUEST_HANDLE(xen_domctl_t) u_domctl)
         static domid_t rover = 0;
         unsigned int domcr_flags;
 
+        ret = -EPERM;
+        if ( !IS_PRIV(current->domain) )
+            break;
+
         ret = -EINVAL;
         if ( supervisor_mode_kernel ||
              (op->u.createdomain.flags & ~XEN_DOMCTL_CDF_hvm_guest) )
@@ -385,12 +398,13 @@ long do_domctl(XEN_GUEST_HANDLE(xen_domctl_t) u_domctl)
         if ( (d = rcu_lock_domain_by_id(op->domain)) == NULL )
             break;
 
+        ret = -EPERM;
+        if ( !IS_PRIV_FOR(current->domain, d) )
+            goto maxvcpu_out2;
+
         ret = xsm_max_vcpus(d);
         if ( ret )
-        {
-            rcu_unlock_domain(d);
-            break;
-        }
+            goto maxvcpu_out2;
 
         /* Needed, for example, to ensure writable p.t. state is synced. */
         domain_pause(d);
@@ -418,6 +432,7 @@ long do_domctl(XEN_GUEST_HANDLE(xen_domctl_t) u_domctl)
 
     maxvcpu_out:
         domain_unpause(d);
+    maxvcpu_out2:
         rcu_unlock_domain(d);
     }
     break;
@@ -428,7 +443,9 @@ long do_domctl(XEN_GUEST_HANDLE(xen_domctl_t) u_domctl)
         ret = -ESRCH;
         if ( d != NULL )
         {
-            ret = xsm_destroydomain(d) ? : domain_kill(d);
+            ret = -EPERM;
+            if ( IS_PRIV_FOR(current->domain, d) )
+                ret = xsm_destroydomain(d) ? : domain_kill(d);
             rcu_unlock_domain(d);
         }
     }
@@ -446,6 +463,10 @@ long do_domctl(XEN_GUEST_HANDLE(xen_domctl_t) u_domctl)
         if ( d == NULL )
             break;
 
+        ret = -EPERM;
+        if ( !IS_PRIV_FOR(current->domain, d) )
+            goto vcpuaffinity_out;
+
         ret = xsm_vcpuaffinity(op->cmd, d);
         if ( ret )
             goto vcpuaffinity_out;
@@ -484,6 +505,10 @@ long do_domctl(XEN_GUEST_HANDLE(xen_domctl_t) u_domctl)
         if ( (d = rcu_lock_domain_by_id(op->domain)) == NULL )
             break;
 
+        ret = -EPERM;
+        if ( !IS_PRIV_FOR(current->domain, d) )
+            goto scheduler_op_out;
+
         ret = xsm_scheduler(d);
         if ( ret )
             goto scheduler_op_out;
@@ -505,7 +530,7 @@ long do_domctl(XEN_GUEST_HANDLE(xen_domctl_t) u_domctl)
         rcu_read_lock(&domlist_read_lock);
 
         for_each_domain ( d )
-            if ( d->domain_id >= dom )
+            if ( d->domain_id >= dom && IS_PRIV_FOR(current->domain, d))
                 break;
 
         if ( d == NULL )
@@ -540,6 +565,10 @@ long do_domctl(XEN_GUEST_HANDLE(xen_domctl_t) u_domctl)
         if ( (d = rcu_lock_domain_by_id(op->domain)) == NULL )
             break;
 
+        ret = -EPERM;
+        if ( !IS_PRIV_FOR(current->domain, d) )
+            goto getvcpucontext_out;
+
         ret = xsm_getvcpucontext(d);
         if ( ret )
             goto getvcpucontext_out;
@@ -600,6 +629,10 @@ long do_domctl(XEN_GUEST_HANDLE(xen_domctl_t) u_domctl)
         if ( (d = rcu_lock_domain_by_id(op->domain)) == NULL )
             break;
 
+        ret = -EPERM;
+        if ( !IS_PRIV_FOR(current->domain, d) )
+            goto getvcpuinfo_out;
+
         ret = xsm_getvcpuinfo(d);
         if ( ret )
             goto getvcpuinfo_out;
@@ -639,6 +672,10 @@ long do_domctl(XEN_GUEST_HANDLE(xen_domctl_t) u_domctl)
         if ( d == NULL )
             break;
 
+        ret = -EPERM;
+        if ( !IS_PRIV_FOR(current->domain, d) )
+            goto max_mem_out;
+
         ret = xsm_setdomainmaxmem(d);
         if ( ret )
             goto max_mem_out;
@@ -655,6 +692,8 @@ long do_domctl(XEN_GUEST_HANDLE(xen_domctl_t) u_domctl)
             d->max_pages = new_max;
             ret = 0;
         }
+        else
+            printk("new max %ld, tot pages %d\n", new_max, d->tot_pages);
         spin_unlock(&d->page_alloc_lock);
 
     max_mem_out:
@@ -671,17 +710,19 @@ long do_domctl(XEN_GUEST_HANDLE(xen_domctl_t) u_domctl)
         if ( d == NULL )
             break;
 
+        ret = -EPERM;
+        if ( !IS_PRIV_FOR(current->domain, d) )
+            goto setdomainhandle_out;
+
         ret = xsm_setdomainhandle(d);
         if ( ret )
-        {
-            rcu_unlock_domain(d);
-            break;
-        }
+            goto setdomainhandle_out;
 
         memcpy(d->handle, op->u.setdomainhandle.handle,
                sizeof(xen_domain_handle_t));
-        rcu_unlock_domain(d);
         ret = 0;
+setdomainhandle_out:
+        rcu_unlock_domain(d);
     }
     break;
 
@@ -694,18 +735,20 @@ long do_domctl(XEN_GUEST_HANDLE(xen_domctl_t) u_domctl)
         if ( d == NULL )
             break;
 
+        ret = -EPERM;
+        if ( !IS_PRIV_FOR(current->domain, d) )
+            goto setdebugging_out;
+
         ret = xsm_setdebugging(d);
         if ( ret )
-        {
-            rcu_unlock_domain(d);
-            break;
-        }
+            goto setdebugging_out;
 
         domain_pause(d);
         d->debugger_attached = !!op->u.setdebugging.enable;
         domain_unpause(d); /* causes guest to latch new status */
-        rcu_unlock_domain(d);
         ret = 0;
+setdebugging_out:
+        rcu_unlock_domain(d);
     }
     break;
 
@@ -723,6 +766,10 @@ long do_domctl(XEN_GUEST_HANDLE(xen_domctl_t) u_domctl)
         if ( d == NULL )
             break;
 
+        ret = -EPERM;
+        if ( !IS_PRIV_FOR(current->domain, d) )
+            goto irq_permission_out;
+
         ret = xsm_irq_permission(d, pirq, op->u.irq_permission.allow_access);
         if ( ret )
             goto irq_permission_out;
@@ -752,6 +799,10 @@ long do_domctl(XEN_GUEST_HANDLE(xen_domctl_t) u_domctl)
         if ( d == NULL )
             break;
 
+        ret = -EPERM;
+        if ( !IS_PRIV_FOR(current->domain, d) )
+            goto iomem_permission_out;
+
         ret = xsm_iomem_permission(d, mfn, op->u.iomem_permission.allow_access);
         if ( ret )
             goto iomem_permission_out;
@@ -772,19 +823,61 @@ long do_domctl(XEN_GUEST_HANDLE(xen_domctl_t) u_domctl)
 
         ret = -ESRCH;
         d = rcu_lock_domain_by_id(op->domain);
-        if ( d != NULL )
-        {
-            ret = xsm_domain_settime(d);
-            if ( ret )
-            {
-                rcu_unlock_domain(d);
-                break;
-            }
+        if ( d == NULL )
+            break;
 
-            d->time_offset_seconds = op->u.settimeoffset.time_offset_seconds;
-            rcu_unlock_domain(d);
-            ret = 0;
+        ret = -EPERM;
+        if ( !IS_PRIV_FOR(current->domain, d) )
+            goto settimeoffset_out;
+
+        ret = xsm_domain_settime(d);
+        if ( ret )
+            goto settimeoffset_out;
+
+        d->time_offset_seconds = op->u.settimeoffset.time_offset_seconds;
+
+        ret = 0;
+settimeoffset_out:
+        rcu_unlock_domain(d);
+    }
+    break;
+
+    case XEN_DOMCTL_set_target:
+    {
+        struct domain *d, *e;
+
+        ret = -ESRCH;
+        d = rcu_lock_domain_by_id(op->domain);
+        if ( d == NULL )
+            break;
+
+        ret = -EPERM;
+        if (!IS_PRIV_FOR(current->domain, d))
+            goto set_target_out;
+
+        ret = -ESRCH;
+        e = get_domain_by_id(op->u.set_target.target);
+        if ( e == NULL )
+            goto set_target_out;
+
+        if ( d == e ) {
+            ret = -EINVAL;
+            put_domain(e);
+            goto set_target_out;
         }
+
+        if (!IS_PRIV_FOR(current->domain, e)) {
+            ret = -EPERM;
+            put_domain(e);
+            goto set_target_out;
+        }
+
+        d->target = e;
+        /* and we keep the reference on e, released when destroying d */
+        ret = 0;
+
+set_target_out:
+        rcu_unlock_domain(d);
     }
     break;
 
diff --git a/xen/common/event_channel.c b/xen/common/event_channel.c
index 3a82e7c6aa..7777822fb6 100644
--- a/xen/common/event_channel.c
+++ b/xen/common/event_channel.c
@@ -130,12 +130,15 @@ static long evtchn_alloc_unbound(evtchn_alloc_unbound_t *alloc)
     long           rc;
 
     if ( dom == DOMID_SELF )
-        dom = current->domain->domain_id;
-    else if ( !IS_PRIV(current->domain) )
-        return -EPERM;
-
-    if ( (d = rcu_lock_domain_by_id(dom)) == NULL )
-        return -ESRCH;
+        d = current->domain;
+    else {
+        if ( (d = rcu_lock_domain_by_id(dom)) == NULL )
+            return -ESRCH;
+        if ( !IS_PRIV_FOR(current->domain, d) ) {
+            rc = -EPERM;
+            goto out2;
+        }
+    }
 
     spin_lock(&d->evtchn_lock);
 
@@ -156,6 +159,7 @@ static long evtchn_alloc_unbound(evtchn_alloc_unbound_t *alloc)
  out:
     spin_unlock(&d->evtchn_lock);
 
+ out2:
     rcu_unlock_domain(d);
 
     return rc;
@@ -197,7 +201,7 @@ static long evtchn_bind_interdomain(evtchn_bind_interdomain_t *bind)
         ERROR_EXIT_DOM(-EINVAL, rd);
     rchn = evtchn_from_port(rd, rport);
     if ( (rchn->state != ECS_UNBOUND) ||
-         (rchn->u.unbound.remote_domid != ld->domain_id) )
+            (rchn->u.unbound.remote_domid != ld->domain_id && !IS_PRIV_FOR(ld, rd)))
         ERROR_EXIT_DOM(-EINVAL, rd);
 
     rc = xsm_evtchn_interdomain(ld, lchn, rd, rchn);
@@ -628,12 +632,15 @@ static long evtchn_status(evtchn_status_t *status)
     long             rc = 0;
 
     if ( dom == DOMID_SELF )
-        dom = current->domain->domain_id;
-    else if ( !IS_PRIV(current->domain) )
-        return -EPERM;
-
-    if ( (d = rcu_lock_domain_by_id(dom)) == NULL )
-        return -ESRCH;
+        d = current->domain;
+    else {
+        if ( (d = rcu_lock_domain_by_id(dom)) == NULL )
+            return -ESRCH;
+        if ( !IS_PRIV_FOR(current->domain, d) ) {
+            rc = -EPERM;
+            goto out2;
+        }
+    }
 
     spin_lock(&d->evtchn_lock);
 
@@ -684,6 +691,7 @@ static long evtchn_status(evtchn_status_t *status)
 
  out:
     spin_unlock(&d->evtchn_lock);
+ out2:
     rcu_unlock_domain(d);
     return rc;
 }
@@ -782,26 +790,28 @@ static long evtchn_reset(evtchn_reset_t *r)
     int rc;
 
     if ( dom == DOMID_SELF )
-        dom = current->domain->domain_id;
-    else if ( !IS_PRIV(current->domain) )
-        return -EPERM;
-
-    if ( (d = rcu_lock_domain_by_id(dom)) == NULL )
-        return -ESRCH;
+        d = current->domain;
+    else {
+        if ( (d = rcu_lock_domain_by_id(dom)) == NULL )
+            return -ESRCH;
+        if ( !IS_PRIV_FOR(current->domain, d) ) {
+            rc = -EPERM;
+            goto out;
+        }
+    }
 
     rc = xsm_evtchn_reset(current->domain, d);
     if ( rc )
-    {
-        rcu_unlock_domain(d);
-        return rc;
-    }
+        goto out;
 
     for ( i = 0; port_is_valid(d, i); i++ )
         (void)__evtchn_close(d, i);
 
+    rc = 0;
+out:
     rcu_unlock_domain(d);
 
-    return 0;
+    return rc;
 }
 
 
diff --git a/xen/common/grant_table.c b/xen/common/grant_table.c
index 7aaad6417c..6f402832f5 100644
--- a/xen/common/grant_table.c
+++ b/xen/common/grant_table.c
@@ -834,19 +834,19 @@ gnttab_setup_table(
     dom = op.dom;
     if ( dom == DOMID_SELF )
     {
-        dom = current->domain->domain_id;
+        d = current->domain;
     }
-    else if ( unlikely(!IS_PRIV(current->domain)) )
-    {
-        op.status = GNTST_permission_denied;
-        goto out;
-    }
-
-    if ( unlikely((d = rcu_lock_domain_by_id(dom)) == NULL) )
-    {
-        gdprintk(XENLOG_INFO, "Bad domid %d.\n", dom);
-        op.status = GNTST_bad_domain;
-        goto out;
+    else {
+        if ( unlikely((d = rcu_lock_domain_by_id(dom)) == NULL) )
+        {
+            gdprintk(XENLOG_INFO, "Bad domid %d.\n", dom);
+            op.status = GNTST_bad_domain;
+            goto out;
+        }
+        if ( unlikely(!IS_PRIV_FOR(current->domain, d)) ) {
+            op.status = GNTST_permission_denied;
+            goto setup_unlock_out2;
+        }
     }
 
     if ( xsm_grant_setup(current->domain, d) )
@@ -880,6 +880,7 @@ gnttab_setup_table(
  setup_unlock_out:
     spin_unlock(&d->grant_table->lock);
 
+ setup_unlock_out2:
     rcu_unlock_domain(d);
 
  out:
@@ -910,27 +911,26 @@ gnttab_query_size(
     dom = op.dom;
     if ( dom == DOMID_SELF )
     {
-        dom = current->domain->domain_id;
+        d = current->domain;
     }
-    else if ( unlikely(!IS_PRIV(current->domain)) )
-    {
-        op.status = GNTST_permission_denied;
-        goto query_out;
-    }
-
-    if ( unlikely((d = rcu_lock_domain_by_id(dom)) == NULL) )
-    {
-        gdprintk(XENLOG_INFO, "Bad domid %d.\n", dom);
-        op.status = GNTST_bad_domain;
-        goto query_out;
+    else {
+        if ( unlikely((d = rcu_lock_domain_by_id(dom)) == NULL) )
+        {
+            gdprintk(XENLOG_INFO, "Bad domid %d.\n", dom);
+            op.status = GNTST_bad_domain;
+            goto query_out;
+        }
+        if ( unlikely(!IS_PRIV_FOR(current->domain, d)) ) {
+            op.status = GNTST_permission_denied;
+            goto query_out_unlock;
+        }
     }
 
     rc = xsm_grant_query_size(current->domain, d);
     if ( rc )
     {
-        rcu_unlock_domain(d);
         op.status = GNTST_permission_denied;
-        goto query_out;
+        goto query_out_unlock;
     }
 
     spin_lock(&d->grant_table->lock);
@@ -941,6 +941,8 @@ gnttab_query_size(
 
     spin_unlock(&d->grant_table->lock);
 
+ 
+ query_out_unlock:
     rcu_unlock_domain(d);
 
  query_out:
diff --git a/xen/common/memory.c b/xen/common/memory.c
index 849e2c1cd8..a3c2ad65e6 100644
--- a/xen/common/memory.c
+++ b/xen/common/memory.c
@@ -232,12 +232,17 @@ static long translate_gpfn_list(
         return -EFAULT;
 
     if ( op.domid == DOMID_SELF )
-        op.domid = current->domain->domain_id;
-    else if ( !IS_PRIV(current->domain) )
-        return -EPERM;
+        d = current->domain;
+    else {
+        d = rcu_lock_domain_by_id(op.domid);
+        if ( d == NULL )
+            return -ESRCH;
+        if ( !IS_PRIV_FOR(current->domain, d) ) {
+            rcu_unlock_domain(d);
+            return -EPERM;
+        }
+    }
 
-    if ( (d = rcu_lock_domain_by_id(op.domid)) == NULL )
-        return -ESRCH;
 
     if ( !paging_mode_translate(d) )
     {
@@ -535,9 +540,15 @@ long do_memory_op(unsigned long cmd, XEN_GUEST_HANDLE(void) arg)
 
         if ( likely(reservation.domid == DOMID_SELF) )
             d = current->domain;
-        else if ( !IS_PRIV(current->domain) ||
-                  ((d = rcu_lock_domain_by_id(reservation.domid)) == NULL) )
-            return start_extent;
+        else {
+            d = rcu_lock_domain_by_id(reservation.domid);
+            if ( d == NULL)
+                return start_extent;
+            if ( !IS_PRIV_FOR(current->domain, d) ) {
+                rcu_unlock_domain(d);
+                return start_extent;
+            }
+        }
         args.domain = d;
 
         rc = xsm_memory_adjust_reservation(current->domain, d);
@@ -589,10 +600,15 @@ long do_memory_op(unsigned long cmd, XEN_GUEST_HANDLE(void) arg)
 
         if ( likely(domid == DOMID_SELF) )
             d = current->domain;
-        else if ( !IS_PRIV(current->domain) )
-            return -EPERM;
-        else if ( (d = rcu_lock_domain_by_id(domid)) == NULL )
-            return -ESRCH;
+        else {
+            d = rcu_lock_domain_by_id(domid);
+            if ( d == NULL )
+                return -ESRCH;
+            if ( !IS_PRIV_FOR(current->domain, d) ) {
+                rcu_unlock_domain(d);
+                return -EPERM;
+            }
+        }
 
         rc = xsm_memory_stat_reservation(current->domain, d);
         if ( rc )
diff --git a/xen/common/schedule.c b/xen/common/schedule.c
index 9c70b97030..8af024f2de 100644
--- a/xen/common/schedule.c
+++ b/xen/common/schedule.c
@@ -461,9 +461,6 @@ ret_t do_sched_op(int cmd, XEN_GUEST_HANDLE(void) arg)
         struct domain *d;
         struct sched_remote_shutdown sched_remote_shutdown;
 
-        if ( !IS_PRIV(current->domain) )
-            return -EPERM;
-
         ret = -EFAULT;
         if ( copy_from_guest(&sched_remote_shutdown, arg, 1) )
             break;
@@ -473,6 +470,12 @@ ret_t do_sched_op(int cmd, XEN_GUEST_HANDLE(void) arg)
         if ( d == NULL )
             break;
 
+        if ( !IS_PRIV_FOR(current->domain, d) )
+        {
+            rcu_unlock_domain(d);
+            return -EPERM;
+        }
+
         ret = xsm_schedop_shutdown(current->domain, d);
         if ( ret )
         {
diff --git a/xen/include/public/domctl.h b/xen/include/public/domctl.h
index a0d3673af8..99822e3d46 100644
--- a/xen/include/public/domctl.h
+++ b/xen/include/public/domctl.h
@@ -554,6 +554,17 @@ struct xen_domctl_set_opt_feature {
 typedef struct xen_domctl_set_opt_feature xen_domctl_set_opt_feature_t;
 DEFINE_XEN_GUEST_HANDLE(xen_domctl_set_opt_feature_t);
 
+/*
+ * Set the target domain for a domain
+ */
+#define XEN_DOMCTL_set_target    46
+struct xen_domctl_set_target {
+    domid_t target;
+};
+typedef struct xen_domctl_set_target xen_domctl_set_target_t;
+DEFINE_XEN_GUEST_HANDLE(xen_domctl_set_target_t);
+
+
 struct xen_domctl {
     uint32_t cmd;
     uint32_t interface_version; /* XEN_DOMCTL_INTERFACE_VERSION */
@@ -590,6 +601,7 @@ struct xen_domctl {
         struct xen_domctl_pin_mem_cacheattr pin_mem_cacheattr;
         struct xen_domctl_ext_vcpucontext   ext_vcpucontext;
         struct xen_domctl_set_opt_feature   set_opt_feature;
+        struct xen_domctl_set_target        set_target;
         uint8_t                             pad[128];
     } u;
 };
diff --git a/xen/include/xen/sched.h b/xen/include/xen/sched.h
index 85cdb6e9a5..a2983aed6a 100644
--- a/xen/include/xen/sched.h
+++ b/xen/include/xen/sched.h
@@ -187,6 +187,8 @@ struct domain
     bool_t           is_hvm;
     /* Is this guest fully privileged (aka dom0)? */
     bool_t           is_privileged;
+    /* Which guest this guest has privileges on */
+    struct domain   *target;
     /* Is this guest being debugged by dom0? */
     bool_t           debugger_attached;
     /* Are any VCPUs polling event channels (SCHEDOP_poll)? */
@@ -493,6 +495,7 @@ static inline void vcpu_unblock(struct vcpu *v)
 }
 
 #define IS_PRIV(_d) ((_d)->is_privileged)
+#define IS_PRIV_FOR(_d, _t) (IS_PRIV(_d) || ((_d)->target && (_d)->target == (_t)))
 
 #ifndef IS_COMPAT
 #define IS_COMPAT(d) 0
diff --git a/xen/xsm/acm/acm_simple_type_enforcement_hooks.c b/xen/xsm/acm/acm_simple_type_enforcement_hooks.c
index 652351ab05..d58c49fcd4 100644
--- a/xen/xsm/acm/acm_simple_type_enforcement_hooks.c
+++ b/xen/xsm/acm/acm_simple_type_enforcement_hooks.c
@@ -817,17 +817,19 @@ ste_pre_grant_setup (domid_t id)
         return ACM_ACCESS_PERMITTED;
     }
     atomic_inc(&ste_bin_pol.gt_eval_count);
+    subj = current->domain;
+    obj = rcu_lock_domain_by_id(id);
+
     /* a) check authorization (eventually use specific capabilities) */
-    if ( !IS_PRIV(current->domain) )
+    if ( obj && !IS_PRIV_FOR(current->domain, obj) )
     {
         printk("%s: Grant table management authorization denied ERROR!\n",
                __func__);
+        rcu_unlock_domain(obj);
         return ACM_ACCESS_DENIED;
     }
-    /* b) check types */
-    subj = current->domain;
-    obj = rcu_lock_domain_by_id(id);
 
+    /* b) check types */
     if ( share_common_type(subj, obj) )
     {
         cache_result(subj, obj);