xenddomaininfo.py

xen虚拟机源代码安装包

#===========================================================================
# This library is free software; you can redistribute it and/or
# modify it under the terms of version 2.1 of the GNU Lesser General Public
# License as published by the Free Software Foundation.
#
# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
#============================================================================
# Copyright (C) 2004, 2005 Mike Wray <[e-mail]>
# Copyright (C) 2005-2007 XenSource Ltd
#============================================================================

"""Representation of a single domain.
Includes support for domain construction, using
open-ended configurations.

Author: Mike Wray <[e-mail]>

"""

import logging
import time
import threading
import re
import copy
import os
import traceback
from types import StringTypes

import xen.lowlevel.xc
from xen.util import asserts
from xen.util.blkif import blkdev_uname_to_file, blkdev_uname_to_taptype
import xen.util.xsm.xsm as security
from xen.util import xsconstants

from xen.xend import balloon, sxp, uuid, image, arch, osdep
from xen.xend import XendOptions, XendNode, XendConfig

from xen.xend.XendConfig import scrub_password
from xen.xend.XendBootloader import bootloader, bootloader_tidy
from xen.xend.XendError import XendError, VmError
from xen.xend.XendDevices import XendDevices
from xen.xend.XendTask import XendTask
from xen.xend.xenstore.xstransact import xstransact, complete
from xen.xend.xenstore.xsutil import GetDomainPath, IntroduceDomain, SetTarget, ResumeDomain
from xen.xend.xenstore.xswatch import xswatch
from xen.xend.XendConstants import *
from xen.xend.XendAPIConstants import *

from xen.xend.XendVMMetrics import XendVMMetrics

from xen.xend.XendPPCI import XendPPCI
from xen.xend.XendDPCI import XendDPCI
from xen.xend import XendAPIStore

MIGRATE_TIMEOUT = 30.0
BOOTLOADER_LOOPBACK_DEVICE = '/dev/xvdp'

xc = xen.lowlevel.xc.xc()
xoptions = XendOptions.instance()

log = logging.getLogger("xend.XendDomainInfo")
#log.setLevel(logging.TRACE)


def create(config):
    """Creates and start a VM using the supplied configuration. 

    @param config: A configuration object involving lists of tuples.
    @type  config: list of lists, eg ['vm', ['image', 'xen.gz']]

    @rtype:  XendDomainInfo
    @return: An up and running XendDomainInfo instance
    @raise VmError: Invalid configuration or failure to start.
    """
    from xen.xend import XendDomain
    domconfig = XendConfig.XendConfig(sxp_obj = config)
    othervm = XendDomain.instance().domain_lookup_nr(domconfig["name_label"])
    if othervm is None or othervm.domid is None:
        othervm = XendDomain.instance().domain_lookup_nr(domconfig["uuid"])
    if othervm is not None and othervm.domid is not None:
        raise VmError("Domain '%s' already exists with ID '%d'" % (domconfig["name_label"], othervm.domid))
    log.debug("XendDomainInfo.create(%s)", scrub_password(config))
    vm = XendDomainInfo(domconfig)
    try:
        vm.start()
    except:
        log.exception('Domain construction failed')
        vm.destroy()
        raise

    return vm

def create_from_dict(config_dict):
    """Creates and start a VM using the supplied configuration. 

    @param config_dict: An configuration dictionary.

    @rtype:  XendDomainInfo
    @return: An up and running XendDomainInfo instance
    @raise VmError: Invalid configuration or failure to start.
    """

    log.debug("XendDomainInfo.create_from_dict(%s)",
              scrub_password(config_dict))
    vm = XendDomainInfo(XendConfig.XendConfig(xapi = config_dict))
    try:
        vm.start()
    except:
        log.exception('Domain construction failed')
        vm.destroy()
        raise
    return vm

def recreate(info, priv):
    """Create the VM object for an existing domain.  The domain must not
    be dying, as the paths in the store should already have been removed,
    and asking us to recreate them causes problems.

    @param xeninfo: Parsed configuration
    @type  xeninfo: Dictionary
    @param priv: Is a privileged domain (Dom 0)
    @type  priv: bool

    @rtype:  XendDomainInfo
    @return: A up and running XendDomainInfo instance
    @raise VmError: Invalid configuration.
    @raise XendError: Errors with configuration.
    """

    log.debug("XendDomainInfo.recreate(%s)", scrub_password(info))

    assert not info['dying']

    xeninfo = XendConfig.XendConfig(dominfo = info)
    xeninfo['is_control_domain'] = priv
    xeninfo['is_a_template'] = False
    domid = xeninfo['domid']
    uuid1 = uuid.fromString(xeninfo['uuid'])
    needs_reinitialising = False
    
    dompath = GetDomainPath(domid)
    if not dompath:
        raise XendError('No domain path in store for existing '
                        'domain %d' % domid)

    log.info("Recreating domain %d, UUID %s. at %s" %
             (domid, xeninfo['uuid'], dompath))

    # need to verify the path and uuid if not Domain-0
    # if the required uuid and vm aren't set, then that means
    # we need to recreate the dom with our own values
    #
    # NOTE: this is probably not desirable, really we should just
    #       abort or ignore, but there may be cases where xenstore's
    #       entry disappears (eg. xenstore-rm /)
    #
    try:
        vmpath = xstransact.Read(dompath, "vm")
        if not vmpath:
            if not priv:
                log.warn('/local/domain/%d/vm is missing. recreate is '
                         'confused, trying our best to recover' % domid)
            needs_reinitialising = True
            raise XendError('reinit')
        
        uuid2_str = xstransact.Read(vmpath, "uuid")
        if not uuid2_str:
            log.warn('%s/uuid/ is missing. recreate is confused, '
                     'trying our best to recover' % vmpath)
            needs_reinitialising = True
            raise XendError('reinit')
        
        uuid2 = uuid.fromString(uuid2_str)
        if uuid1 != uuid2:
            log.warn('UUID in /vm does not match the UUID in /dom/%d.'
                     'Trying out best to recover' % domid)
            needs_reinitialising = True
    except XendError:
        pass # our best shot at 'goto' in python :)

    vm = XendDomainInfo(xeninfo, domid, dompath, augment = True, priv = priv,
                        vmpath = vmpath)
    
    if needs_reinitialising:
        vm._recreateDom()
        vm._removeVm()
        vm._storeVmDetails()
        vm._storeDomDetails()
        
    vm.image = image.create(vm, vm.info)
    vm.image.recreate()

    vm._registerWatches()
    vm.refreshShutdown(xeninfo)

    # register the domain in the list 
    from xen.xend import XendDomain
    XendDomain.instance().add_domain(vm)

    return vm


def restore(config):
    """Create a domain and a VM object to do a restore.

    @param config: Domain SXP configuration
    @type  config: list of lists. (see C{create})

    @rtype:  XendDomainInfo
    @return: A up and running XendDomainInfo instance
    @raise VmError: Invalid configuration or failure to start.
    @raise XendError: Errors with configuration.
    """

    log.debug("XendDomainInfo.restore(%s)", scrub_password(config))
    vm = XendDomainInfo(XendConfig.XendConfig(sxp_obj = config),
                        resume = True)
    try:
        vm.resume()
        return vm
    except:
        vm.destroy()
        raise

def createDormant(domconfig):
    """Create a dormant/inactive XenDomainInfo without creating VM.
    This is for creating instances of persistent domains that are not
    yet start.

    @param domconfig: Parsed configuration
    @type  domconfig: XendConfig object
    
    @rtype:  XendDomainInfo
    @return: A up and running XendDomainInfo instance
    @raise XendError: Errors with configuration.    
    """
    
    log.debug("XendDomainInfo.createDormant(%s)", scrub_password(domconfig))
    
    # domid does not make sense for non-running domains.
    domconfig.pop('domid', None)
    vm = XendDomainInfo(domconfig)
    return vm    

def domain_by_name(name):
    """Get domain by name

    @params name: Name of the domain
    @type   name: string
    @return: XendDomainInfo or None
    """
    from xen.xend import XendDomain
    return XendDomain.instance().domain_lookup_by_name_nr(name)


def shutdown_reason(code):
    """Get a shutdown reason from a code.

    @param code: shutdown code
    @type  code: int
    @return: shutdown reason
    @rtype:  string
    """
    return DOMAIN_SHUTDOWN_REASONS.get(code, "?")

def dom_get(dom):
    """Get info from xen for an existing domain.

    @param dom: domain id
    @type  dom: int
    @return: info or None
    @rtype: dictionary
    """
    try:
        domlist = xc.domain_getinfo(dom, 1)
        if domlist and dom == domlist[0]['domid']:
            return domlist[0]
    except Exception, err:
        # ignore missing domain
        log.trace("domain_getinfo(%d) failed, ignoring: %s", dom, str(err))
    return None


class XendDomainInfo:
    """An object represents a domain.

    @TODO: try to unify dom and domid, they mean the same thing, but
           xc refers to it as dom, and everywhere else, including
           xenstore it is domid. The best way is to change xc's
           python interface.

    @ivar info: Parsed configuration
    @type info: dictionary
    @ivar domid: Domain ID (if VM has started)
    @type domid: int or None
    @ivar vmpath: XenStore path to this VM.
    @type vmpath: string
    @ivar dompath: XenStore path to this Domain.
    @type dompath: string
    @ivar image:  Reference to the VM Image.
    @type image: xen.xend.image.ImageHandler
    @ivar store_port: event channel to xenstored
    @type store_port: int
    @ivar console_port: event channel to xenconsoled
    @type console_port: int
    @ivar store_mfn: xenstored mfn
    @type store_mfn: int
    @ivar console_mfn: xenconsoled mfn
    @type console_mfn: int
    @ivar notes: OS image notes
    @type notes: dictionary
    @ivar vmWatch: reference to a watch on the xenstored vmpath
    @type vmWatch: xen.xend.xenstore.xswatch
    @ivar shutdownWatch: reference to watch on the xenstored domain shutdown
    @type shutdownWatch: xen.xend.xenstore.xswatch
    @ivar shutdownStartTime: UNIX Time when domain started shutting down.
    @type shutdownStartTime: float or None
#    @ivar state: Domain state
#    @type state: enum(DOM_STATE_HALTED, DOM_STATE_RUNNING, ...)
    @ivar state_updated: lock for self.state
    @type state_updated: threading.Condition
    @ivar refresh_shutdown_lock: lock for polling shutdown state
    @type refresh_shutdown_lock: threading.Condition
    @ivar _deviceControllers: device controller cache for this domain
    @type _deviceControllers: dict 'string' to DevControllers
    """
    
    def __init__(self, info, domid = None, dompath = None, augment = False,
                 priv = False, resume = False, vmpath = None):
        """Constructor for a domain

        @param   info: parsed configuration
        @type    info: dictionary
        @keyword domid: Set initial domain id (if any)
        @type    domid: int
        @keyword dompath: Set initial dompath (if any)
        @type    dompath: string
        @keyword augment: Augment given info with xenstored VM info
        @type    augment: bool
        @keyword priv: Is a privileged domain (Dom 0)
        @type    priv: bool
        @keyword resume: Is this domain being resumed?
        @type    resume: bool
        """

        self.info = info
        if domid == None:
            self.domid =  self.info.get('domid')