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# Copyright (C) 2005 Christian Limpach <Christian.Limpach@cl.cam.ac.uk>
# This file is subject to the terms and conditions of the GNU General
# Public License. See the file "COPYING" in the main directory of
# this archive for more details.
import errno
import os
import select
import sxp
from string import join
from struct import pack, unpack, calcsize
from xen.util.xpopen import xPopen3
import xen.lowlevel.xc; xc = xen.lowlevel.xc.new()
from XendError import XendError
from XendLogging import log
SIGNATURE = "LinuxGuestRecord"
PAGE_SIZE = 4096
PATH_XC_SAVE = "/usr/libexec/xen/xc_save"
PATH_XC_RESTORE = "/usr/libexec/xen/xc_restore"
sizeof_int = calcsize("i")
sizeof_unsigned_long = calcsize("L")
def write_exact(fd, buf, errmsg):
if os.write(fd, buf) != len(buf):
raise XendError(errmsg)
def read_exact(fd, size, errmsg):
buf = os.read(fd, size)
if len(buf) != size:
raise XendError(errmsg)
return buf
def save(xd, fd, dominfo):
write_exact(fd, SIGNATURE, "could not write guest state file: signature")
config = sxp.to_string(dominfo.sxpr())
write_exact(fd, pack("!i", len(config)),
"could not write guest state file: config len")
write_exact(fd, config, "could not write guest state file: config")
cmd = [PATH_XC_SAVE, str(xc.handle()), str(fd),
str(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 %d" % dominfo.id)
xd.domain_shutdown(dominfo.id, reason='suspend')
dominfo.state_wait("suspended")
log.info("suspend %d 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)
xd.domain_destroy(dominfo.id)
return None
def restore(xd, fd):
signature = read_exact(fd, len(SIGNATURE),
"not a valid guest state file: signature read")
if signature != SIGNATURE:
raise XendError("not a valid guest state file: found '%s'" %
signature)
l = read_exact(fd, sizeof_int,
"not a valid guest state file: config size read")
vmconfig_size = unpack("!i", l)[0]
vmconfig_buf = read_exact(fd, vmconfig_size,
"not a valid guest state file: config read")
p = sxp.Parser()
p.input(vmconfig_buf)
if not p.ready:
raise XendError("not a valid guest state file: config parse")
vmconfig = p.get_val()
dominfo = xd.domain_configure(vmconfig)
l = read_exact(fd, sizeof_unsigned_long,
"not a valid guest state file: pfn count read")
nr_pfns = unpack("=L", l)[0] # XXX endianess
if nr_pfns > 1024*1024: # XXX
raise XendError(
"not a valid guest state file: pfn count out of range")
cmd = [PATH_XC_RESTORE, str(xc.handle()), str(fd),
str(dominfo.id), str(nr_pfns)]
log.info("[xc_restore] " + join(cmd))
child = xPopen3(cmd, True, -1, [fd, xc.handle()])
child.tochild.close()
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()
log.info(l.rstrip())
if filter(lambda (fd, event): event & select.POLLHUP, r):
break
if child.wait() >> 8 == 127:
lasterr = "popen %s failed" % PATH_XC_RESTORE
if child.wait() != 0:
raise XendError("xc_restore failed: %s" % lasterr)
return dominfo
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