bitkeeper revision 1.1527.2.1 (429368a2F0SR4yrzuHsrRucuwriYqA)

Implement the parts of vm save which need interaction with xend
as part of xend, instead of using xfrd.
Execute xc_linux_save in a seperate process so that it can't
crash xend.  Also handle errors passed from xc_linux_save.
xen_domain.c:
  Disable save in xfrd.
xc_save.c:
  new file
Makefile:
  Add xc_save.
XendDomainInfo.py:
  Add suspended state and threading Condition with notification, allowing
  easy waiting for state changes.
XendDomain.py:
  Implement the parts of vm save which need interaction with xend
  as part of xend, instead of using xfrd.  Set state to "suspended"
  when detecting a suspended domain.
  Fix reading output from subprocesses.
  Fix ValueError in xen_domain().
xc.c:
  Remove python binding for xc_linux_save.
xc_linux_save.c:
  Implement the parts of vm save which need interaction with xend
  as part of xend, instead of using xfrd.  Also run xc_linux_save
  in a seperate process.
xc_linux_restore.c:
  Flush output so that xend picks it up timely.
  Also disable debug output again.
xc.h:
  Update xc_linux_save prototype and fix comments for xc_linux_{save,restore}.
ignore:
  Add tools/xcutils/xc_save.
xpopen.py:
  Exit with 127 if exec fails.
Signed-off-by: Christian Limpach <Christian.Limpach@cl.cam.ac.uk>

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

@@ -254,93 +254,6 @@ static PyObject *pyxc_domain_getinfo(PyObject *self,
     return list;
 }
 
-static int file_save(XcObject *xc, XcIOContext *ctxt, char *state_file)
-{
-    int rc = -1;
-    int fd = -1;
-    int open_flags = (O_CREAT | O_EXCL | O_WRONLY);
-    int open_mode = 0644;
-
-    printf("%s>\n", __FUNCTION__);
-
-    if ( (fd = open(state_file, open_flags, open_mode)) < 0 )
-    {
-        xcio_perror(ctxt, "Could not open file for writing");
-        goto exit;
-    }
-
-    printf("%s>gzip_stream_fdopen... \n", __FUNCTION__);
-
-    /* Compression rate 1: we want speed over compression. 
-     * We're mainly going for those zero pages, after all.
-     */
-    ctxt->io = gzip_stream_fdopen(fd, "wb1");
-    if ( ctxt->io == NULL )
-    {
-        xcio_perror(ctxt, "Could not allocate compression state");
-        goto exit;
-    }
-
-    printf("%s> xc_linux_save...\n", __FUNCTION__);
-
-    rc = xc_linux_save(xc->xc_handle, ctxt);
-
-  exit:
-    if ( ctxt->io != NULL )
-        IOStream_close(ctxt->io);
-    if ( fd >= 0 )
-        close(fd);
-    unlink(state_file);
-    printf("%s> rc=%d\n", __FUNCTION__, rc);
-    return rc;
-}
-
-static PyObject *pyxc_linux_save(PyObject *self,
-                                 PyObject *args,
-                                 PyObject *kwds)
-{
-    XcObject *xc = (XcObject *)self;
-
-    char *state_file;
-    int progress = 1, debug = 0;
-    PyObject *val = NULL;
-    int rc = -1;
-    XcIOContext ioctxt = { .info = iostdout, .err = iostderr };
-
-    static char *kwd_list[] = { "dom", "state_file", "vmconfig", "progress", "debug", NULL };
-
-    if ( !PyArg_ParseTupleAndKeywords(args, kwds, "is|sii", kwd_list, 
-                                      &ioctxt.domain,
-                                      &state_file,
-                                      &ioctxt.vmconfig,
-                                      &progress, 
-                                      &debug) )
-        goto exit;
-
-    ioctxt.vmconfig_n = (ioctxt.vmconfig ? strlen(ioctxt.vmconfig) : 0);
-
-    if ( progress )
-        ioctxt.flags |= XCFLAGS_VERBOSE;
-    if ( debug )
-        ioctxt.flags |= XCFLAGS_DEBUG;
-
-    if ( (state_file == NULL) || (state_file[0] == '\0') )
-        goto exit;
-    
-    rc = file_save(xc, &ioctxt, state_file);
-    if ( rc != 0 )
-    {
-        PyErr_SetFromErrno(xc_error);
-        goto exit;
-    } 
-
-    Py_INCREF(zero);
-    val = zero;
-
-  exit:
-    return val;
-}
-
 static PyObject *pyxc_linux_build(PyObject *self,
                                   PyObject *args,
                                   PyObject *kwds)
@@ -999,15 +912,6 @@ static PyMethodDef pyxc_methods[] = {
       "reason why it shut itself down.\n" 
       " vcpu_to_cpu [[int]]: List that maps VCPUS to CPUS\n" },
 
-    { "linux_save", 
-      (PyCFunction)pyxc_linux_save, 
-      METH_VARARGS | METH_KEYWORDS, "\n"
-      "Save the CPU and memory state of a Linux guest OS.\n"
-      " dom        [int]:    Identifier of domain to be saved.\n"
-      " state_file [str]:    Name of state file. Must not currently exist.\n"
-      " progress   [int, 1]: Bool - display a running progress indication?\n\n"
-      "Returns: [int] 0 on success; -1 on error.\n" },
-
     { "linux_build", 
       (PyCFunction)pyxc_linux_build, 
       METH_VARARGS | METH_KEYWORDS, "\n"

tools/python/xen/util/xpopen.py

@@ -129,7 +129,7 @@ class xPopen3:
         try:
             os.execvp(cmd[0], cmd)
         finally:
-            os._exit(1)
+            os._exit(127)
 
     def poll(self):
         """Return the exit status of the child process if it has finished,

tools/python/xen/xend/XendDomain.py

@@ -90,7 +90,10 @@ class XendDomain:
         """Get info about a single domain from xc.
         Returns None if not found.
         """
-        dom = int(dom)
+        try:
+            dom = int(dom)
+        except ValueError:
+            return None
         dominfo = xc.domain_getinfo(dom, 1)
         if dominfo == [] or dominfo[0]['dom'] != dom:
             dominfo = None
@@ -198,6 +201,8 @@ class XendDomain:
                         log.debug('XendDomain>reap> Suspended domain died id=%s', id)
                     else:
                         eserver.inject('xend.domain.suspended', [name, id])
+                        if dominfo:
+                            dominfo.state_set("suspended")
                         continue
                 if reason in ['poweroff', 'reboot']:
                     eserver.inject('xend.domain.exit', [name, id, reason])
@@ -349,7 +354,7 @@ class XendDomain:
 
             l = fd.read_exact(sizeof_int,
                               "not a valid guest state file: config size read")
-            vmconfig_size = unpack("i", l)[0] # XXX endianess
+            vmconfig_size = unpack("!i", l)[0]
             vmconfig_buf = fd.read_exact(vmconfig_size,
                 "not a valid guest state file: config read")
 
@@ -384,17 +389,22 @@ class XendDomain:
             p.register(child.childerr.fileno())
             while True:
                 r = p.poll()
-                for l in child.childerr.readlines():
-                    log.error(l.rstrip())
-                    lasterr = l.rstrip()
-                for l in child.fromchild.readlines():
-                    log.info(l.rstrip())
+                for (fd, event) in r:
+                    if not event & select.POLLIN:
+                        continue
+                    if fd == child.childerr.fileno():
+                        l = child.childerr.readline()
+                        log.error(l.rstrip())
+                        lasterr = l.rstrip()
+                    if fd == child.fromchild.fileno():
+                        l = child.fromchild.readline()
+                        log.info(l.rstrip())
                 if filter(lambda (fd, event): event & select.POLLHUP, r):
                     break
 
             if child.wait() != 0:
                 raise XendError("xc_restore failed: %s" % lasterr)
-            
+
             return dominfo
 
         except IOError, ex:
@@ -592,10 +602,66 @@ class XendDomain:
         @param dst:      destination file
         @param progress: output progress if true
         """
-        dominfo = self.domain_lookup(id)
-        xmigrate = XendMigrate.instance()
-        return xmigrate.save_begin(dominfo, dst)
-    
+
+        SIGNATURE = "LinuxGuestRecord"
+        sizeof_int = calcsize("i")
+        PATH_XC_SAVE = "/usr/libexec/xen/xc_save"
+
+        try:
+            dominfo = self.domain_lookup(id)
+
+            fd = os.open(dst, os.O_WRONLY | os.O_CREAT | os.O_TRUNC)
+
+            if os.write(fd, SIGNATURE) != len(SIGNATURE):
+                raise XendError("could not write guest state file: signature")
+
+            config = sxp.to_string(dominfo.sxpr())
+            if os.write(fd, pack("!i", len(config))) != sizeof_int:
+                raise XendError("could not write guest state file: config len")
+            if os.write(fd, config) != len(config):
+                raise XendError("could not write guest state file: config")
+
+            cmd = [PATH_XC_SAVE, str(xc.handle()), str(fd),
+                   dominfo.id]
+            log.info("[xc_save] " + join(cmd))
+            child = xPopen3(cmd, True, -1, [fd, xc.handle()])
+            
+            lasterr = ""
+            p = select.poll()
+            p.register(child.fromchild.fileno())
+            p.register(child.childerr.fileno())
+            while True:
+                r = p.poll()
+                for (fd, event) in r:
+                    if not event & select.POLLIN:
+                        continue
+                    if fd == child.childerr.fileno():
+                        l = child.childerr.readline()
+                        log.error(l.rstrip())
+                        lasterr = l.rstrip()
+                    if fd == child.fromchild.fileno():
+                        l = child.fromchild.readline()
+                        if l.rstrip() == "suspend":
+                            log.info("suspending %s" % dominfo.id)
+                            self.domain_shutdown(dominfo.id, reason='suspend')
+                            dominfo.state_wait("suspended")
+                            log.info("suspend %s done" % dominfo.id)
+                            child.tochild.write("done\n")
+                            child.tochild.flush()
+                if filter(lambda (fd, event): event & select.POLLHUP, r):
+                    break
+
+            if child.wait() >> 8 == 127:
+                lasterr = "popen %s failed" % PATH_XC_SAVE
+            if child.wait() != 0:
+                raise XendError("xc_save failed: %s" % lasterr)
+
+            self.domain_destroy(dominfo.id)
+            return None
+
+        except:
+            raise
+
     def domain_pincpu(self, id, vcpu, cpumap):
         """Set which cpus vcpu can use
 

tools/python/xen/xend/XendDomainInfo.py

@@ -11,6 +11,7 @@ Author: Mike Wray <mike.wray@hp.com>
 import string
 import os
 import time
+import threading
 
 import xen.lowlevel.xc; xc = xen.lowlevel.xc.new()
 import xen.util.ip
@@ -74,6 +75,7 @@ STATE_RESTART_BOOTING = 'booting'
 
 STATE_VM_OK         = "ok"
 STATE_VM_TERMINATED = "terminated"
+STATE_VM_SUSPENDED  = "suspended"
 
 
 def domain_exists(name):
@@ -288,6 +290,7 @@ class XendDomainInfo:
         self.netif_backend = False
         #todo: state: running, suspended
         self.state = STATE_VM_OK
+        self.state_updated = threading.Condition()
         self.shutdown_pending = None
 
         #todo: set to migrate info if migrating
@@ -328,6 +331,19 @@ class XendDomainInfo:
         self.info = info
         self.memory = self.info['mem_kb'] / 1024
 
+    def state_set(self, state):
+        self.state_updated.acquire()
+        if self.state != state:
+            self.state = state
+            self.state_updated.notifyAll()
+        self.state_updated.release()
+
+    def state_wait(self, state):
+        self.state_updated.acquire()
+        while self.state != state:
+            self.state_updated.wait()
+        self.state_updated.release()
+
     def __str__(self):
         s = "domain"
         s += " id=" + self.id