#
# The Qubes OS Project, https://www.qubes-os.org/
#
# Copyright (C) 2016 Marek Marczykowski-Górecki
# <[email protected]>
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.
#
# 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, see <https://www.gnu.org/licenses/>.
#
''' Qubes PCI Extensions '''
import functools
import os
import re
import subprocess
import libvirt
import lxml
import lxml.etree
import qubes.devices
import qubes.ext
#: cache of PCI device classes
pci_classes = None
def load_pci_classes():
''' List of known device classes, subclasses and programming interfaces. '''
# Syntax:
# C class class_name
# subclass subclass_name <-- single tab
# prog-if prog-if_name <-- two tabs
result = {}
with open('/usr/share/hwdata/pci.ids',
encoding='utf-8', errors='ignore') as pciids:
class_id = None
subclass_id = None
for line in pciids.readlines():
line = line.rstrip()
if line.startswith('\t\t') and class_id and subclass_id:
(progif_id, _, class_name) = line[2:].split(' ', 2)
result[class_id + subclass_id + progif_id] = \
class_name
elif line.startswith('\t') and class_id:
(subclass_id, _, class_name) = line[1:].split(' ', 2)
# store both prog-if specific entry and generic one
result[class_id + subclass_id + '00'] = \
class_name
result[class_id + subclass_id] = \
class_name
elif line.startswith('C '):
(_, class_id, _, class_name) = line.split(' ', 3)
result[class_id + '0000'] = class_name
result[class_id + '00'] = class_name
subclass_id = None
return result
def pcidev_class(dev_xmldesc):
sysfs_path = dev_xmldesc.findtext('path')
assert sysfs_path
try:
with open(sysfs_path + '/class') as f_class:
class_id = f_class.read().strip()
except OSError:
return "Unknown"
if not qubes.ext.pci.pci_classes:
qubes.ext.pci.pci_classes = load_pci_classes()
if class_id.startswith('0x'):
class_id = class_id[2:]
try:
# ignore prog-if
return qubes.ext.pci.pci_classes[class_id[0:4]]
except KeyError:
return "Unknown"
def attached_devices(app):
"""Return map device->domain-name for all currently attached devices"""
# Libvirt do not expose nice API to query where the device is
# attached. The only way would be to query _all_ the domains (
# each with separate libvirt call) and look if the device is
# there. Horrible waste of resources.
# Instead, do this on much lower level - xenstore info for
# xen-pciback driver, where we get all the info at once
xs = app.vmm.xs
devices = {}
for domid in xs.ls('', 'backend/pci') or []:
for devid in xs.ls('', 'backend/pci/' + domid) or []:
devpath = 'backend/pci/' + domid + '/' + devid
domain_name = xs.read('', devpath + '/domain')
try:
domain = app.domains[domain_name]
except KeyError:
# unknown domain - maybe from another qubes.xml?
continue
devnum = xs.read('', devpath + '/num_devs')
for dev in range(int(devnum)):
dbdf = xs.read('', devpath + '/dev-' + str(dev))
bdf = dbdf[len('0000:'):]
devices[bdf.replace(':', '_')] = domain
return devices
def _device_desc(hostdev_xml):
return '{devclass}: {vendor} {product}'.format(
devclass=pcidev_class(hostdev_xml),
vendor=hostdev_xml.findtext('capability/vendor'),
product=hostdev_xml.findtext('capability/product'),
)
class PCIDevice(qubes.devices.DeviceInfo):
# pylint: disable=too-few-public-methods
regex = re.compile(
r'^(?P<bus>[0-9a-f]+)_(?P<device>[0-9a-f]+)\.(?P<function>[0-9a-f]+)$')
_libvirt_regex = re.compile(
r'^pci_0000_(?P<bus>[0-9a-f]+)_(?P<device>[0-9a-f]+)_'
r'(?P<function>[0-9a-f]+)$')
def __init__(self, backend_domain, ident, libvirt_name=None):
if libvirt_name:
dev_match = self._libvirt_regex.match(libvirt_name)
assert dev_match
ident = '{bus}_{device}.{function}'.format(**dev_match.groupdict())
super(PCIDevice, self).__init__(backend_domain, ident, None)
# lazy loading
self._description = None
@property
def libvirt_name(self):
# pylint: disable=no-member
# noinspection PyUnresolvedReferences
return 'pci_0000_{}_{}_{}'.format(self.bus, self.device, self.function)
@property
def description(self):
if self._description is None:
hostdev_details = \
self.backend_domain.app.vmm.libvirt_conn.nodeDeviceLookupByName(
self.libvirt_name
)
self._description = _device_desc(lxml.etree.fromstring(
hostdev_details.XMLDesc()))
return self._description
@property
def frontend_domain(self):
# TODO: cache this
all_attached = attached_devices(self.backend_domain.app)
return all_attached.get(self.ident, None)
[docs]class PCIDeviceExtension(qubes.ext.Extension):
def __init__(self):
super(PCIDeviceExtension, self).__init__()
# lazy load this
self.pci_classes = {}
@qubes.ext.handler('device-list:pci')
def on_device_list_pci(self, vm, event):
# pylint: disable=unused-argument,no-self-use
# only dom0 expose PCI devices
if vm.qid != 0:
return
for dev in vm.app.vmm.libvirt_conn.listAllDevices():
if 'pci' not in dev.listCaps():
continue
xml_desc = lxml.etree.fromstring(dev.XMLDesc())
libvirt_name = xml_desc.findtext('name')
yield PCIDevice(vm, None, libvirt_name=libvirt_name)
@qubes.ext.handler('device-get:pci')
def on_device_get_pci(self, vm, event, ident):
# pylint: disable=unused-argument,no-self-use
if not vm.app.vmm.offline_mode:
yield _cache_get(vm, ident)
@qubes.ext.handler('device-list-attached:pci')
def on_device_list_attached(self, vm, event, **kwargs):
# pylint: disable=unused-argument,no-self-use
if not vm.is_running() or isinstance(vm, qubes.vm.adminvm.AdminVM):
return
xml_desc = lxml.etree.fromstring(vm.libvirt_domain.XMLDesc())
for hostdev in xml_desc.findall('devices/hostdev'):
if hostdev.get('type') != 'pci':
continue
address = hostdev.find('source/address')
bus = address.get('bus')[2:]
device = address.get('slot')[2:]
function = address.get('function')[2:]
ident = '{bus}_{device}.{function}'.format(
bus=bus,
device=device,
function=function,
)
yield (PCIDevice(vm.app.domains[0], ident), {})
@qubes.ext.handler('device-pre-attach:pci')
def on_device_pre_attached_pci(self, vm, event, device, options):
# pylint: disable=unused-argument
if not os.path.exists('/sys/bus/pci/devices/0000:{}'.format(
device.ident.replace('_', ':'))):
raise qubes.exc.QubesException(
'Invalid PCI device: {}'.format(device.ident))
if vm.virt_mode == 'pvh':
raise qubes.exc.QubesException(
"Can't attach PCI device to VM in pvh mode")
if not vm.is_running():
return
try:
device = _cache_get(device.backend_domain, device.ident)
self.bind_pci_to_pciback(vm.app, device)
vm.libvirt_domain.attachDevice(
vm.app.env.get_template('libvirt/devices/pci.xml').render(
device=device, vm=vm, options=options))
except subprocess.CalledProcessError as e:
vm.log.exception('Failed to attach PCI device {!r} on the fly,'
' changes will be seen after VM restart.'.format(
device.ident), e)
@qubes.ext.handler('device-pre-detach:pci')
def on_device_pre_detached_pci(self, vm, event, device):
# pylint: disable=unused-argument,no-self-use
if not vm.is_running():
return
# this cannot be converted to general API, because there is no
# provision in libvirt for extracting device-side BDF; we need it for
# qubes.DetachPciDevice, which unbinds driver, not to oops the kernel
device = _cache_get(device.backend_domain, device.ident)
p = subprocess.Popen(['xl', 'pci-list', str(vm.xid)],
stdout=subprocess.PIPE)
result = p.communicate()[0].decode()
m = re.search(r'^(\d+.\d+)\s+0000:{}$'.format(device.ident.replace(
'_', ':')),
result,
flags=re.MULTILINE)
if not m:
vm.log.error('Device %s already detached', device.ident)
return
vmdev = m.group(1)
try:
vm.run_service('qubes.DetachPciDevice',
user='root', input='00:{}'.format(vmdev))
vm.libvirt_domain.detachDevice(
vm.app.env.get_template('libvirt/devices/pci.xml').render(
device=device, vm=vm))
except (subprocess.CalledProcessError, libvirt.libvirtError) as e:
vm.log.exception('Failed to detach PCI device {!r} on the fly,'
' changes will be seen after VM restart.'.format(
device.ident), e)
raise
@qubes.ext.handler('domain-pre-start')
def on_domain_pre_start(self, vm, _event, **_kwargs):
# Bind pci devices to pciback driver
for assignment in vm.devices['pci'].persistent():
device = _cache_get(assignment.backend_domain, assignment.ident)
self.bind_pci_to_pciback(vm.app, device)
@staticmethod
def bind_pci_to_pciback(app, device):
'''Bind PCI device to pciback driver.
:param qubes.devices.PCIDevice device: device to attach
Devices should be unbound from their normal kernel drivers and bound to
the dummy driver, which allows for attaching them to a domain.
'''
try:
node = app.vmm.libvirt_conn.nodeDeviceLookupByName(
device.libvirt_name)
except libvirt.libvirtError as e:
if e.get_error_code() == libvirt.VIR_ERR_NO_NODE_DEVICE:
raise qubes.exc.QubesException(
'PCI device {!s} does not exist'.format(
device))
raise
try:
node.dettach()
except libvirt.libvirtError as e:
if e.get_error_code() == libvirt.VIR_ERR_INTERNAL_ERROR:
# allreaddy dettached
pass
else:
raise
@functools.lru_cache(maxsize=None)
def _cache_get(vm, ident):
''' Caching wrapper around `PCIDevice(vm, ident)`. '''
return PCIDevice(vm, ident)