Add support for superpages (hugepages) in PV domain

This patch adds the option "superpages" to the domain configuration
file. If it is set, the domain is populated using 2M pages.

This code does not support fallback to small pages.  If the domain can
not be created with 2M pages, the  create will fail.

The patch also includes support for saving and restoring domains with
the superpage flag set.  However, if a domain has freed small pages
within its physical page array and then extended the array, the
restore will fill in those freed pages.  It will then attempt to
allocate more than its memory limit and will fail.  This is
significant because apparently Linux does this during boot, thus a
freshly booted Linux image can not be saved and restored successfully.

Signed-off-by: Dave McCracken <dcm@mccr.org>

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

@@ -405,6 +405,7 @@ static PyObject *pyxc_linux_build(XcObject *self,
     int flags = 0;
     int store_evtchn, console_evtchn;
     int vhpt = 0;
+    int superpages = 0;
     unsigned int mem_mb;
     unsigned long store_mfn = 0;
     unsigned long console_mfn = 0;
@@ -417,14 +418,14 @@ static PyObject *pyxc_linux_build(XcObject *self,
                                 "console_evtchn", "image",
                                 /* optional */
                                 "ramdisk", "cmdline", "flags",
-                                "features", "vhpt", NULL };
+                                "features", "vhpt", "superpages", NULL };
 
-    if ( !PyArg_ParseTupleAndKeywords(args, kwds, "iiiis|ssisi", kwd_list,
+    if ( !PyArg_ParseTupleAndKeywords(args, kwds, "iiiis|ssisii", kwd_list,
                                       &domid, &store_evtchn, &mem_mb,
                                       &console_evtchn, &image,
                                       /* optional */
                                       &ramdisk, &cmdline, &flags,
-                                      &features, &vhpt) )
+                                      &features, &vhpt, &superpages) )
         return NULL;
 
     xc_dom_loginit();
@@ -436,7 +437,7 @@ static PyObject *pyxc_linux_build(XcObject *self,
 
     if ( xc_dom_linux_build(self->xc_handle, dom, domid, mem_mb, image,
                             ramdisk, flags, store_evtchn, &store_mfn,
-                            console_evtchn, &console_mfn) != 0 ) {
+                            console_evtchn, &console_mfn, superpages) != 0 ) {
         goto out;
     }
 

tools/python/xen/xend/XendCheckpoint.py

@@ -272,9 +272,11 @@ def restore(xd, fd, dominfo = None, paused = False, relocating = False):
         shadow_cur = xc.shadow_mem_control(dominfo.getDomid(), shadow / 1024)
         dominfo.info['shadow_memory'] = shadow_cur
 
+        superpages = restore_image.superpages
+
         cmd = map(str, [xen.util.auxbin.pathTo(XC_RESTORE),
                         fd, dominfo.getDomid(),
-                        store_port, console_port, int(is_hvm), pae, apic])
+                        store_port, console_port, int(is_hvm), pae, apic, superpages])
         log.debug("[xc_restore]: %s", string.join(cmd))
 
         handler = RestoreInputHandler()

tools/python/xen/xend/XendConfig.py

@@ -220,6 +220,7 @@ XENAPI_CFG_TYPES = {
     'machine_address_size': int,
     'suppress_spurious_page_faults': bool0,
     's3_integrity' : int,
+    'superpages' : int,
 }
 
 # List of legacy configuration keys that have no equivalent in the
@@ -392,6 +393,7 @@ class XendConfig(dict):
             'other_config': {},
             'platform': {},
             'target': 0,
+            'superpages': 0,
         }
         
         return defaults
@@ -2014,6 +2016,8 @@ class XendConfig(dict):
             image.append(['ramdisk', self['PV_ramdisk']])
         if self.has_key('PV_args') and self['PV_args']:
             image.append(['args', self['PV_args']])
+        if self.has_key('superpages'):
+            image.append(['superpages', self['superpages']])
 
         for key in XENAPI_PLATFORM_CFG_TYPES.keys():
             if key in self['platform']:
@@ -2051,6 +2055,8 @@ class XendConfig(dict):
             self['PV_ramdisk'] = sxp.child_value(image_sxp, 'ramdisk','')
             self['PV_args'] = kernel_args
 
+        self['superpages'] = sxp.child_value(image_sxp, 'superpages',0)
+
         for key in XENAPI_PLATFORM_CFG_TYPES.keys():
             val = sxp.child_value(image_sxp, key, None)
             if val is not None and val != '':

tools/python/xen/xend/image.py

@@ -651,6 +651,7 @@ class LinuxImageHandler(ImageHandler):
         ImageHandler.configure(self, vmConfig)
         self.vramsize = int(vmConfig['platform'].get('videoram',4)) * 1024
         self.is_stubdom = (self.kernel.find('stubdom') >= 0)
+        self.superpages = vmConfig['superpages']
 
     def buildDomain(self):
         store_evtchn = self.vm.getStorePort()
@@ -668,6 +669,7 @@ class LinuxImageHandler(ImageHandler):
         log.debug("vcpus          = %d", self.vm.getVCpuCount())
         log.debug("features       = %s", self.vm.getFeatures())
         log.debug("flags          = %d", self.flags)
+        log.debug("superpages     = %d", self.superpages)
         if arch.type == "ia64":
             log.debug("vhpt          = %d", self.vhpt)
 
@@ -680,7 +682,8 @@ class LinuxImageHandler(ImageHandler):
                               ramdisk        = self.ramdisk,
                               features       = self.vm.getFeatures(),
                               flags          = self.flags,
-                              vhpt           = self.vhpt)
+                              vhpt           = self.vhpt,
+                              superpages     = self.superpages)
 
     def getRequiredAvailableMemory(self, mem_kb):
         if self.is_stubdom :

tools/python/xen/xm/create.dtd

@@ -54,6 +54,7 @@
                  actions_after_reboot   %NORMAL_EXIT; #REQUIRED
                  actions_after_crash    %CRASH_BEHAVIOUR; #REQUIRED
                  PCI_bus                CDATA #REQUIRED
+                 superpages             CDATA #REQUIRED
                  security_label         CDATA #IMPLIED>
 
 <!ELEMENT memory EMPTY> 

tools/python/xen/xm/create.py

@@ -660,6 +660,8 @@ def configure_image(vals):
         config_image.append(['videoram', vals.videoram])
     if vals.extra:
         config_image.append(['args', vals.extra])
+    if vals.superpages:
+        config_image.append(['superpages', vals.superpages])
 
     if vals.builder == 'hvm':
         configure_hvm(config_image, vals) 

tools/python/xen/xm/xenapi_create.py

@@ -271,6 +271,8 @@ class xenapi_create:
                 vm.attributes["auto_power_on"].value == 'true',
             "s3_integrity":
                 vm.attributes["s3_integrity"].value,
+            "superpages":
+                vm.attributes["superpages"].value,
             "memory_static_max":
                 get_child_node_attribute(vm, "memory", "static_max"),
             "memory_static_min":
@@ -654,6 +656,8 @@ class sxp2xml:
             = str(get_child_by_name(config, "vcpus", 1))
         vm.attributes["s3_integrity"] \
             = str(get_child_by_name(config, "s3_integrity", 0))
+        vm.attributes["superpages"] \
+            = str(get_child_by_name(config, "superpages", 0))
 
         sec_data = get_child_by_name(config, "security")
         if sec_data: