Add nomigrate config option to disable migration/restore

The new nomigrate option can be set to non-zero in vm.cfg
(for both hvm and pvm) to disallow a guest from being
migrated or restored.  (Save is still allowed for the purpose
of checkpointing.)  The option persists into a save file
and is also communicated into the hypervisor, the latter
for the purposes of a to-be-added hypercall for communicating
to guests that migration is disallowed (which will be
used initially for userland TSC-related sensing, but may
find other uses).

Signed-off-by: Dan Magenheimer <dan.magenheimer@oracle.com>

tools/python/xen/lowlevel/xc/xc.c

@@ -1485,6 +1485,20 @@ static PyObject *pyxc_domain_set_tsc_native(XcObject *self, PyObject *args)
     return zero;
 }
 
+static PyObject *pyxc_domain_disable_migrate(XcObject *self, PyObject *args)
+{
+    uint32_t dom;
+
+    if (!PyArg_ParseTuple(args, "i", &dom))
+        return NULL;
+
+    if (xc_domain_disable_migrate(self->xc_handle, dom) != 0)
+        return pyxc_error_to_exception();
+
+    Py_INCREF(zero);
+    return zero;
+}
+
 static PyObject *pyxc_domain_send_trigger(XcObject *self,
                                           PyObject *args,
                                           PyObject *kwds)
@@ -2015,6 +2029,13 @@ static PyMethodDef pyxc_methods[] = {
       " is_native  [int]: 1=native, 0=emulate.\n"
       "Returns: [int] 0 on success; -1 on error.\n" },
 
+    { "domain_disable_migrate",
+      (PyCFunction)pyxc_domain_disable_migrate,
+      METH_VARARGS, "\n"
+      "Marks domain as non-migratable AND non-restoreable\n"
+      " dom        [int]: Domain whose TSC mode is being set.\n"
+      "Returns: [int] 0 on success; -1 on error.\n" },
+
     { "domain_send_trigger",
       (PyCFunction)pyxc_domain_send_trigger,
       METH_VARARGS | METH_KEYWORDS, "\n"

tools/python/xen/xend/XendCheckpoint.py

@@ -226,6 +226,19 @@ def restore(xd, fd, dominfo = None, paused = False, relocating = False):
     else:
         dominfo = xd.restore_(vmconfig)
 
+    image_cfg = dominfo.info.get('image', {})
+    is_hvm = dominfo.info.is_hvm()
+
+    if is_hvm:
+        nomigrate = dominfo.info['platform'].get('nomigrate', 0)
+    else:
+        nomigrate = dominfo.info['platform'].get('nomigrate')
+        if nomigrate is None:
+            nomigrate = 0
+    if int(nomigrate) != 0:
+        dominfo.destroy()
+        raise XendError("cannot restore non-migratable domain")
+
     # repin domain vcpus if a target node number was specified 
     # this is done prior to memory allocation to aide in memory
     # distribution for NUMA systems.
@@ -248,8 +261,6 @@ def restore(xd, fd, dominfo = None, paused = False, relocating = False):
     assert console_port
 
     # if hvm, pass mem size to calculate the store_mfn
-    image_cfg = dominfo.info.get('image', {})
-    is_hvm = dominfo.info.is_hvm()
     if is_hvm:
         apic = int(dominfo.info['platform'].get('apic', 0))
         pae  = int(dominfo.info['platform'].get('pae',  0))

tools/python/xen/xend/XendConfig.py

@@ -146,6 +146,7 @@ XENAPI_PLATFORM_CFG_TYPES = {
     'localtime': int,
     'monitor': int,
     'nographic': int,
+    'nomigrate': int,
     'pae' : int,
     'rtc_timeoffset': int,
     'serial': str,
@@ -479,6 +480,9 @@ class XendConfig(dict):
         if 'tsc_native' not in self['platform']:
             self['platform']['tsc_native'] = 0
 
+        if 'nomigrate' not in self['platform']:
+            self['platform']['nomigrate'] = 0
+
         if self.is_hvm():
             if 'timer_mode' not in self['platform']:
                 self['platform']['timer_mode'] = 1

tools/python/xen/xend/XendDomainInfo.py

@@ -2464,6 +2464,11 @@ class XendDomainInfo:
         if arch.type == "x86" and hvm and viridian is not None:
             xc.hvm_set_param(self.domid, HVM_PARAM_VIRIDIAN, long(viridian))
 
+        # If nomigrate is set, disable migration
+        nomigrate = self.info["platform"].get("nomigrate")
+        if arch.type == "x86" and nomigrate is not None and long(nomigrate) != 0:
+            xc.domain_disable_migrate(self.domid)
+
         # Optionally enable virtual HPET
         hpet = self.info["platform"].get("hpet")
         if hvm and hpet is not None:

tools/python/xen/xm/create.py

@@ -225,6 +225,10 @@ gopts.var('tsc_native', val='TSC_NATIVE',
           fn=set_int, default=0,
           use="""TSC mode (0=emulate TSC, 1=native TSC).""")
 
+gopts.var('nomigrate', val='NOMIGRATE',
+          fn=set_int, default=0,
+          use="""migratability (0=migration enabled, 1=migration disabled).""")
+
 gopts.var('vpt_align', val='VPT_ALIGN',
           fn=set_int, default=1,
           use="Enable aligning all periodic vpt to reduce timer interrupts.")
@@ -737,6 +741,9 @@ def configure_image(vals):
     if vals.tsc_native is not None:
         config_image.append(['tsc_native', vals.tsc_native])
 
+    if vals.nomigrate is not None:
+        config_image.append(['nomigrate', vals.nomigrate])
+
     return config_image
     
 def configure_disks(config_devs, vals):
@@ -1020,7 +1027,7 @@ def make_config(vals):
                 config.append([n, v])
 
     map(add_conf, ['name', 'memory', 'maxmem', 'shadow_memory',
-                   'restart', 'on_poweroff', 'tsc_native',
+                   'restart', 'on_poweroff', 'tsc_native', 'nomigrate',
                    'on_reboot', 'on_crash', 'vcpus', 'vcpu_avail', 'features',
                    'on_xend_start', 'on_xend_stop', 'target', 'cpuid',
                    'cpuid_check', 'machine_address_size', 'suppress_spurious_page_faults'])

tools/python/xen/xm/xenapi_create.py

@@ -1079,6 +1079,7 @@ class sxp2xml:
             'xen_platform_pci',
             'tsc_native'
             'description',
+            'nomigrate'
         ]
 
         platform_configs = []