xen/xenpaging.autostart.patch

xenpaging: start xenpaging via config option

Start xenpaging via config option.

TODO: add libxl support
TODO: parse config values like 42K, 42M, 42G, 42%

Signed-off-by: Olaf Hering <olaf@aepfle.de>

---
v4:
  add config option for pagefile directory
  add config option to enable debug
  add config option to set polic mru_size
  fail if chdir fails
  force self.xenpaging* variables to be strings because a xm new may turn some
  of them into type int and later os.execve fails with a TypeError

v3:
  decouple create/destroycreateXenPaging from _create/_removeDevices
  init xenpaging variable to 0 if xenpaging is not in config file to
  avoid string None coming from sxp file

v2:
  unlink logfile instead of truncating it.
  allows hardlinking for further inspection

---
 tools/examples/xmexample.hvm            |   12 ++++
 tools/python/README.XendConfig          |    4 +
 tools/python/README.sxpcfg              |    4 +
 tools/python/xen/xend/XendConfig.py     |   12 ++++
 tools/python/xen/xend/XendDomainInfo.py |   12 ++++
 tools/python/xen/xend/image.py          |   87 ++++++++++++++++++++++++++++++++
 tools/python/xen/xm/create.py           |   20 +++++++
 tools/python/xen/xm/xenapi_create.py    |    4 +
 8 files changed, 155 insertions(+)

Index: xen-4.1.1-testing/tools/examples/xmexample.hvm
===================================================================
--- xen-4.1.1-testing.orig/tools/examples/xmexample.hvm
+++ xen-4.1.1-testing/tools/examples/xmexample.hvm
@@ -127,6 +127,18 @@ disk = [ 'file:/var/lib/xen/images/disk.
 # Device Model to be used
 device_model = 'qemu-dm'
 
+# number of guest pages to page-out, or -1 for entire guest memory range
+xenpaging=42
+
+# directory to store guest page file
+#xenpaging_workdir="/var/lib/xen/xenpaging"
+
+# enable debug output in pager
+#xenpaging_debug=0
+
+# number of paged-in pages to keep in memory
+#xenpaging_policy_mru_size=1024
+
 #-----------------------------------------------------------------------------
 # boot on floppy (a), hard disk (c), Network (n) or CD-ROM (d) 
 # default: hard disk, cd-rom, floppy
Index: xen-4.1.1-testing/tools/python/README.XendConfig
===================================================================
--- xen-4.1.1-testing.orig/tools/python/README.XendConfig
+++ xen-4.1.1-testing/tools/python/README.XendConfig
@@ -120,6 +120,10 @@ otherConfig
                                 image.vncdisplay
                                 image.vncunused
                                 image.hvm.device_model
+                                image.hvm.xenpaging
+                                image.hvm.xenpaging_workdir
+                                image.hvm.xenpaging_debug
+                                image.hvm.xenpaging_policy_mru_size
                                 image.hvm.display
                                 image.hvm.xauthority
                                 image.hvm.vncconsole
Index: xen-4.1.1-testing/tools/python/README.sxpcfg
===================================================================
--- xen-4.1.1-testing.orig/tools/python/README.sxpcfg
+++ xen-4.1.1-testing/tools/python/README.sxpcfg
@@ -51,6 +51,10 @@ image
   - vncunused
   (HVM)
   - device_model
+  - xenpaging
+  - xenpaging_workdir
+  - xenpaging_debug
+  - xenpaging_policy_mru_size
   - display
   - xauthority
   - vncconsole
Index: xen-4.1.1-testing/tools/python/xen/xend/XendConfig.py
===================================================================
--- xen-4.1.1-testing.orig/tools/python/xen/xend/XendConfig.py
+++ xen-4.1.1-testing/tools/python/xen/xend/XendConfig.py
@@ -147,6 +147,10 @@ XENAPI_PLATFORM_CFG_TYPES = {
     'apic': int,
     'boot': str,
     'device_model': str,
+    'xenpaging': str,
+    'xenpaging_workdir': str,
+    'xenpaging_debug': str,
+    'xenpaging_policy_mru_size': str,
     'loader': str,
     'display' : str,
     'fda': str,
@@ -516,6 +520,14 @@ class XendConfig(dict):
             self['platform']['nomigrate'] = 0
 
         if self.is_hvm():
+            if 'xenpaging' not in self['platform']:
+                self['platform']['xenpaging'] = "0"
+            if 'xenpaging_workdir' not in self['platform']:
+                self['platform']['xenpaging_workdir'] = "/var/lib/xen/xenpaging"
+            if 'xenpaging_debug' not in self['platform']:
+                self['platform']['xenpaging_debug'] = "0"
+            if 'xenpaging_policy_mru_size' not in self['platform']:
+                self['platform']['xenpaging_policy_mru_size'] = "0"
             if 'timer_mode' not in self['platform']:
                 self['platform']['timer_mode'] = 1
             if 'extid' in self['platform'] and int(self['platform']['extid']) == 1:
Index: xen-4.1.1-testing/tools/python/xen/xend/XendDomainInfo.py
===================================================================
--- xen-4.1.1-testing.orig/tools/python/xen/xend/XendDomainInfo.py
+++ xen-4.1.1-testing/tools/python/xen/xend/XendDomainInfo.py
@@ -2290,6 +2290,8 @@ class XendDomainInfo:
                  self.info['name_label'], self.domid, self.info['uuid'],
                  new_name, new_uuid)
         self._unwatchVm()
+        if self.image:
+            self.image.destroyXenPaging()
         self._releaseDevices()
         # Remove existing vm node in xenstore
         self._removeVm()
@@ -2961,6 +2963,9 @@ class XendDomainInfo:
 
             self._createDevices()
 
+            if self.image:
+                self.image.createXenPaging()
+
             self.image.cleanupTmpImages()
 
             self.info['start_time'] = time.time()
@@ -2985,6 +2990,8 @@ class XendDomainInfo:
         self.refresh_shutdown_lock.acquire()
         try:
             self.unwatchShutdown()
+            if self.image:
+                self.image.destroyXenPaging()
             self._releaseDevices()
             bootloader_tidy(self)
 
@@ -3069,6 +3076,7 @@ class XendDomainInfo:
         self.image = image.create(self, self.info)
         if self.image:
             self._createDevices(True)
+            self.image.createXenPaging()
         self.console_port = console_port
         self._storeDomDetails()
         self._registerWatches()
@@ -3210,6 +3218,8 @@ class XendDomainInfo:
             # could also fetch a parsed note from xenstore
             fast = self.info.get_notes().get('SUSPEND_CANCEL') and 1 or 0
             if not fast:
+                if self.image:
+                    self.image.destroyXenPaging()
                 self._releaseDevices()
                 self.testDeviceComplete()
                 self.testvifsComplete()
@@ -3225,6 +3235,8 @@ class XendDomainInfo:
                 self._storeDomDetails()
 
                 self._createDevices()
+                if self.image:
+                    self.image.createXenPaging()
                 log.debug("XendDomainInfo.resumeDomain: devices created")
 
             xc.domain_resume(self.domid, fast)
Index: xen-4.1.1-testing/tools/python/xen/xend/image.py
===================================================================
--- xen-4.1.1-testing.orig/tools/python/xen/xend/image.py
+++ xen-4.1.1-testing/tools/python/xen/xend/image.py
@@ -122,6 +122,11 @@ class ImageHandler:
         self.vm.permissionsVm("image/cmdline", { 'dom': self.vm.getDomid(), 'read': True } )
 
         self.device_model = vmConfig['platform'].get('device_model')
+        self.xenpaging = str(vmConfig['platform'].get('xenpaging'))
+        self.xenpaging_workdir = str(vmConfig['platform'].get('xenpaging_workdir'))
+        self.xenpaging_debug = str(vmConfig['platform'].get('xenpaging_debug'))
+        self.xenpaging_policy_mru_size = str(vmConfig['platform'].get('xenpaging_policy_mru_size'))
+        self.xenpaging_pid = None
 
         self.display = vmConfig['platform'].get('display')
         self.xauthority = vmConfig['platform'].get('xauthority')
@@ -392,6 +397,88 @@ class ImageHandler:
         sentinel_fifos_inuse[sentinel_path_fifo] = 1
         self.sentinel_path_fifo = sentinel_path_fifo
 
+    def createXenPaging(self):
+        if not self.vm.info.is_hvm():
+            return
+        if self.xenpaging == "0":
+            return
+        if self.xenpaging_pid:
+            return
+        xenpaging_bin = auxbin.pathTo("xenpaging")
+        args = [xenpaging_bin]
+        args = args + ([ "%d" % self.vm.getDomid()])
+        args = args + ([ "%s" % self.xenpaging])
+        env = dict(os.environ)
+	if not self.xenpaging_debug == "0":
+            env['XENPAGING_DEBUG'] = self.xenpaging_debug
+	if not self.xenpaging_policy_mru_size == "0":
+            env['XENPAGING_POLICY_MRU_SIZE'] = self.xenpaging_policy_mru_size
+        self.xenpaging_logfile = "/var/log/xen/xenpaging-%s.log" %  str(self.vm.info['name_label'])
+        logfile_mode = os.O_WRONLY|os.O_CREAT|os.O_APPEND|os.O_TRUNC
+        null = os.open("/dev/null", os.O_RDONLY)
+        try:
+            os.unlink(self.xenpaging_logfile)
+        except:
+            pass
+        logfd = os.open(self.xenpaging_logfile, logfile_mode, 0644)
+        sys.stderr.flush()
+        contract = osdep.prefork("%s:%d" % (self.vm.getName(), self.vm.getDomid()))
+        xenpaging_pid = os.fork()
+        if xenpaging_pid == 0: #child
+            try:
+                osdep.postfork(contract)
+                os.dup2(null, 0)
+                os.dup2(logfd, 1)
+                os.dup2(logfd, 2)
+                os.chdir(self.xenpaging_workdir)
+                try:
+                    log.info("starting %s" % args)
+                    os.execve(xenpaging_bin, args, env)
+                except Exception, e:
+                    log.warn('failed to execute xenpaging: %s' % utils.exception_string(e))
+                    os._exit(126)
+            except:
+                log.warn("starting xenpaging in %s failed" % self.xenpaging_workdir)
+                os._exit(127)
+        else:
+            osdep.postfork(contract, abandon=True)
+            self.xenpaging_pid = xenpaging_pid
+            os.close(null)
+            os.close(logfd)
+
+    def destroyXenPaging(self):
+        if self.xenpaging == "0":
+            return
+        if self.xenpaging_pid:
+            try:
+                os.kill(self.xenpaging_pid, signal.SIGHUP)
+            except OSError, exn:
+                log.exception(exn)
+            for i in xrange(100):
+                try:
+                    (p, rv) = os.waitpid(self.xenpaging_pid, os.WNOHANG)
+                    if p == self.xenpaging_pid:
+                        break
+                except OSError:
+                    # This is expected if Xend has been restarted within
+                    # the life of this domain.  In this case, we can kill
+                    # the process, but we can't wait for it because it's
+                    # not our child. We continue this loop, and after it is
+                    # terminated make really sure the process is going away
+                    # (SIGKILL).
+                    pass
+                time.sleep(0.1)
+            else:
+                log.warning("xenpaging %d took more than 10s "
+                            "to terminate: sending SIGKILL" % self.xenpaging_pid)
+                try:
+                    os.kill(self.xenpaging_pid, signal.SIGKILL)
+                    os.waitpid(self.xenpaging_pid, 0)
+                except OSError:
+                    # This happens if the process doesn't exist.
+                    pass
+        self.xenpaging_pid = None
+
     def createDeviceModel(self, restore = False):
         if self.device_model is None:
             return
Index: xen-4.1.1-testing/tools/python/xen/xm/create.py
===================================================================
--- xen-4.1.1-testing.orig/tools/python/xen/xm/create.py
+++ xen-4.1.1-testing/tools/python/xen/xm/create.py
@@ -495,6 +495,22 @@ gopts.var('nfs_root', val="PATH",
           fn=set_value, default=None,
           use="Set the path of the root NFS directory.")
 
+gopts.var('xenpaging', val='NUM',
+          fn=set_value, default='0',
+          use="Number of pages to swap.")
+
+gopts.var('xenpaging_workdir', val='PATH',
+          fn=set_value, default='/var/lib/xen/xenpaging',
+          use="Number of pages to swap.")
+
+gopts.var('xenpaging_debug', val='NUM',
+          fn=set_value, default='0',
+          use="Number of pages to swap.")
+
+gopts.var('xenpaging_policy_mru_size', val='NUM',
+          fn=set_value, default='0',
+          use="Number of pages to swap.")
+
 gopts.var('device_model', val='FILE',
           fn=set_value, default=None,
           use="Path to device model program.")
@@ -1095,6 +1111,10 @@ def configure_hvm(config_image, vals):
     args = [ 'acpi', 'apic',
              'boot',
              'cpuid', 'cpuid_check',
+             'xenpaging',
+             'xenpaging_workdir',
+             'xenpaging_debug',
+             'xenpaging_policy_mru_size',
              'device_model', 'display',
              'fda', 'fdb',
              'gfx_passthru', 'guest_os_type',
Index: xen-4.1.1-testing/tools/python/xen/xm/xenapi_create.py
===================================================================
--- xen-4.1.1-testing.orig/tools/python/xen/xm/xenapi_create.py
+++ xen-4.1.1-testing/tools/python/xen/xm/xenapi_create.py
@@ -1085,6 +1085,10 @@ class sxp2xml:
             'acpi',
             'apic',
             'boot',
+            'xenpaging',
+            'xenpaging_workdir',
+            'xenpaging_debug',
+            'xenpaging_policy_mru_size',
             'device_model',
             'loader',
             'fda',