Rework QubesWatch implementation for libvirt events
This commit is contained in:
Marek Marczykowski-Górecki
parent
d4ab70ae9d
commit
adff88101a
@ -157,6 +157,7 @@ class QubesVMMConnection(object):
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if 'xen.lowlevel.xs' in sys.modules:
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self._xs = xen.lowlevel.xs.xs()
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libvirt.virEventRegisterDefaultImpl()
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self._libvirt_conn = libvirt.open(defaults['libvirt_uri'])
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if self._libvirt_conn == None:
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raise QubesException("Failed connect to libvirt driver")
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@ -21,6 +21,7 @@
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# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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#
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#
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import string
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from lxml import etree
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from lxml.etree import ElementTree, SubElement, Element
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@ -34,6 +35,8 @@ import subprocess
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import re
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import time
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import stat
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import libvirt
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from qdb import QubesDB,Error,DisconnectedError
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import xen.lowlevel.xc
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import xen.lowlevel.xs
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@ -695,94 +698,105 @@ def only_in_first_list(l1, l2):
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return ret
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class QubesWatch(object):
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class WatchType(object):
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def __init__(self, fn, param):
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self.fn = fn
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self.param = param
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def __init__(self):
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self.xs = xen.lowlevel.xs.xs()
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self.watch_tokens_block = {}
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self.watch_tokens_vbd = {}
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self.watch_tokens_meminfo = {}
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self._qdb = {}
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self._qdb_events = {}
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self.block_callback = None
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self.meminfo_callback = None
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self.domain_callback = None
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self.xs.watch('@introduceDomain', QubesWatch.WatchType(self.domain_list_changed, None))
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self.xs.watch('@releaseDomain', QubesWatch.WatchType(self.domain_list_changed, None))
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vmm.libvirt_conn.domainEventRegisterAny(
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None,
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libvirt.VIR_DOMAIN_EVENT_ID_LIFECYCLE,
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self._domain_list_changed, None)
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vmm.libvirt_conn.domainEventRegisterAny(
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None,
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libvirt.VIR_DOMAIN_EVENT_ID_DEVICE_REMOVED,
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self._device_removed, None)
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# TODO: device attach libvirt event
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for vm in vmm.libvirt_conn.listAllDomains():
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if vm.isActive():
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self._register_watches(vm)
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# and for dom0
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self._register_watches(None)
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def _qdb_handler(self, watch, fd, events, domain_name):
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try:
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path = self._qdb[domain_name].read_watch()
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except DisconnectedError:
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libvirt.virEventRemoveHandle(watch)
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del(self._qdb_events[domain_name])
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self._qdb[domain_name].close()
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del(self._qdb[domain_name])
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return
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if path.startswith('/qubes-block-devices'):
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if self.block_callback is not None:
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self.block_callback(domain_name)
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def setup_block_watch(self, callback):
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old_block_callback = self.block_callback
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self.block_callback = callback
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if old_block_callback is not None and callback is None:
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# remove watches
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self.update_watches_block([])
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else:
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# possibly add watches
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self.domain_list_changed(None)
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def setup_meminfo_watch(self, callback):
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old_meminfo_callback = self.meminfo_callback
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self.meminfo_callback = callback
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if old_meminfo_callback is not None and callback is None:
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# remove watches
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self.update_watches_meminfo([])
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else:
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# possibly add watches
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self.domain_list_changed(None)
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raise NotImplemented
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def setup_domain_watch(self, callback):
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self.domain_callback = callback
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def get_block_key(self, xid):
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return '/local/domain/%s/qubes-block-devices' % xid
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def get_vbd_key(self, xid):
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return '/local/domain/%s/device/vbd' % xid
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def get_meminfo_key(self, xid):
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return '/local/domain/%s/memory/meminfo' % xid
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def update_watches(self, xid_list, watch_tokens, xs_key_func, callback):
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for i in only_in_first_list(xid_list, watch_tokens.keys()):
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#new domain has been created
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watch = QubesWatch.WatchType(callback, i)
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watch_tokens[i] = watch
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self.xs.watch(xs_key_func(i), watch)
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for i in only_in_first_list(watch_tokens.keys(), xid_list):
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#domain destroyed
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self.xs.unwatch(xs_key_func(i), watch_tokens[i])
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watch_tokens.pop(i)
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def update_watches_block(self, xid_list):
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self.update_watches(xid_list, self.watch_tokens_block,
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self.get_block_key, self.block_callback)
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self.update_watches(xid_list, self.watch_tokens_vbd,
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self.get_vbd_key, self.block_callback)
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def update_watches_meminfo(self, xid_list):
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self.update_watches(xid_list, self.watch_tokens_meminfo,
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self.get_meminfo_key, self.meminfo_callback)
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def domain_list_changed(self, param):
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curr = self.xs.ls('', '/local/domain')
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if curr == None:
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def _register_watches(self, libvirt_domain):
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if libvirt_domain:
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name = libvirt_domain.name()
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if name in self._qdb:
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return
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if self.domain_callback:
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self.domain_callback()
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if self.block_callback:
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self.update_watches_block(curr)
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if self.meminfo_callback:
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self.update_watches_meminfo(curr)
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# open separate connection to Qubes DB:
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# 1. to not confuse pull() with responses to real commands sent from
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# other threads (like read, write etc) with watch events
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# 2. to not think whether QubesDB is thread-safe (it isn't)
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while libvirt_domain.isActive() and name not in self._qdb:
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try:
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self._qdb[name] = QubesDB(name)
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except Error as e:
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if e.args[0] != 2:
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raise
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time.sleep(0.5)
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else:
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name = "dom0"
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self._qdb[name] = QubesDB(name)
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self._qdb[name].watch('/qubes-block-devices')
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self._qdb_events[name] = libvirt.virEventAddHandle(
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self._qdb[name].watch_fd(),
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libvirt.VIR_EVENT_HANDLE_READABLE,
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self._qdb_handler, name)
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def watch_single(self):
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result = self.xs.read_watch()
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token = result[1]
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token.fn(token.param)
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def _unregister_watches(self, libvirt_domain):
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name = libvirt_domain.name()
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if name in self._qdb_events:
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libvirt.virEventRemoveHandle(self._qdb_events[name])
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del(self._qdb_events[name])
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if name in self._qdb:
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self._qdb[name].close()
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del(self._qdb[name])
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def _domain_list_changed(self, conn, domain, event, reason, param):
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if event == libvirt.VIR_DOMAIN_EVENT_STARTED:
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self._register_watches(domain)
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elif event == libvirt.VIR_DOMAIN_EVENT_STOPPED:
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self._unregister_watches(domain)
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else:
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# ignore other events for now
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return None
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if self.domain_callback:
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self.domain_callback(name=domain.name())
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def _device_removed(self, conn, domain, device, param):
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if self.block_callback is not None:
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self.block_callback(domain.name())
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def watch_loop(self):
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while True:
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self.watch_single()
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libvirt.virEventRunDefaultImpl()
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##### updates check #####
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