virt-manager/virtinst/capabilities.py

316 lines
9.3 KiB
Python

#
# Some code for parsing libvirt's capabilities XML
#
# Copyright 2007, 2012-2014 Red Hat, Inc.
#
# This work is licensed under the GNU GPLv2 or later.
# See the COPYING file in the top-level directory.
import pwd
from .domain import DomainCpu
from .logger import log
from .xmlbuilder import XMLBuilder, XMLChildProperty, XMLProperty
###################################
# capabilities host <cpu> parsing #
###################################
class _CapsCPU(DomainCpu):
arch = XMLProperty("./arch")
###########################
# Caps <topology> parsers #
###########################
class _CapsTopologyCPU(XMLBuilder):
XML_NAME = "cpu"
id = XMLProperty("./@id")
class _TopologyCell(XMLBuilder):
XML_NAME = "cell"
cpus = XMLChildProperty(_CapsTopologyCPU, relative_xpath="./cpus")
class _CapsTopology(XMLBuilder):
XML_NAME = "topology"
cells = XMLChildProperty(_TopologyCell, relative_xpath="./cells")
######################################
# Caps <host> and <secmodel> parsers #
######################################
class _CapsSecmodelBaselabel(XMLBuilder):
XML_NAME = "baselabel"
type = XMLProperty("./@type")
content = XMLProperty(".")
class _CapsSecmodel(XMLBuilder):
XML_NAME = "secmodel"
model = XMLProperty("./model")
baselabels = XMLChildProperty(_CapsSecmodelBaselabel)
class _CapsHost(XMLBuilder):
XML_NAME = "host"
secmodels = XMLChildProperty(_CapsSecmodel)
cpu = XMLChildProperty(_CapsCPU, is_single=True)
topology = XMLChildProperty(_CapsTopology, is_single=True)
def get_qemu_baselabel(self):
for secmodel in self.secmodels:
if secmodel.model != "dac":
continue
label = None
for baselabel in secmodel.baselabels:
if baselabel.type in ["qemu", "kvm"]:
label = baselabel.content
break
if not label:
continue # pragma: no cover
# XML we are looking at is like:
#
# <secmodel>
# <model>dac</model>
# <doi>0</doi>
# <baselabel type='kvm'>+107:+107</baselabel>
# <baselabel type='qemu'>+107:+107</baselabel>
# </secmodel>
try:
uid = int(label.split(":")[0].replace("+", ""))
user = pwd.getpwuid(uid)[0]
return user, uid
except Exception: # pragma: no cover
log.debug("Exception parsing qemu dac baselabel=%s",
label, exc_info=True)
return None, None # pragma: no cover
################################
# <guest> and <domain> parsers #
################################
class _CapsMachine(XMLBuilder):
XML_NAME = "machine"
name = XMLProperty(".")
canonical = XMLProperty("./@canonical")
class _CapsDomain(XMLBuilder):
XML_NAME = "domain"
hypervisor_type = XMLProperty("./@type")
emulator = XMLProperty("./emulator")
machines = XMLChildProperty(_CapsMachine)
class _CapsGuestFeatures(XMLBuilder):
XML_NAME = "features"
pae = XMLProperty("./pae", is_bool=True)
acpi = XMLProperty("./acpi/@default", is_onoff=True)
apic = XMLProperty("./apic/@default", is_onoff=True)
class _CapsGuest(XMLBuilder):
XML_NAME = "guest"
os_type = XMLProperty("./os_type")
arch = XMLProperty("./arch/@name")
loader = XMLProperty("./arch/loader")
emulator = XMLProperty("./arch/emulator")
domains = XMLChildProperty(_CapsDomain, relative_xpath="./arch")
features = XMLChildProperty(_CapsGuestFeatures, is_single=True)
machines = XMLChildProperty(_CapsMachine, relative_xpath="./arch")
###############
# Public APIs #
###############
def all_machine_names(self, domain):
"""
Return all machine string names, including canonical aliases for
the guest+domain combo
"""
mobjs = (domain and domain.machines) or self.machines
ret = []
for m in mobjs:
ret.append(m.name)
if m.canonical:
ret.append(m.canonical)
return ret
def has_install_options(self):
"""
Return True if there are any install options available
"""
return bool(len(self.domains) > 0)
def is_kvm_available(self):
"""
Return True if kvm guests can be installed
"""
for d in self.domains:
if d.hypervisor_type == "kvm":
return True
return False
def supports_pae(self):
"""
Return True if capabilities report support for PAE
"""
return bool(self.features.pae)
def supports_acpi(self):
"""
Return Tree if capabilities report support for ACPI
"""
return bool(self.features.acpi)
def supports_apic(self):
"""
Return Tree if capabilities report support for APIC
"""
return bool(self.features.apic)
############################
# Main capabilities object #
############################
class _CapsInfo(object):
"""
Container object to hold the results of guest_lookup, so users don't
need to juggle two objects
"""
def __init__(self, conn, guest, domain):
self.conn = conn
self.guest = guest
self.domain = domain
self.hypervisor_type = self.domain.hypervisor_type
self.os_type = self.guest.os_type
self.arch = self.guest.arch
self.loader = self.guest.loader
self.emulator = self.domain.emulator or self.guest.emulator
self.machines = self.guest.all_machine_names(self.domain)
class Capabilities(XMLBuilder):
def __init__(self, *args, **kwargs):
XMLBuilder.__init__(self, *args, **kwargs)
self._cpu_models_cache = {}
XML_NAME = "capabilities"
host = XMLChildProperty(_CapsHost, is_single=True)
guests = XMLChildProperty(_CapsGuest)
############################
# Public XML building APIs #
############################
def _guestForOSType(self, os_type, arch):
archs = [arch]
if arch is None:
archs = [self.host.cpu.arch, None]
for a in archs:
for g in self.guests:
if ((os_type is None or g.os_type == os_type) and
(a is None or g.arch == a)):
return g
def _bestDomainType(self, guest, dtype, machine):
"""
Return the recommended domain for use if the user does not explicitly
request one.
"""
domains = []
for d in guest.domains:
if dtype and d.hypervisor_type != dtype.lower():
continue
if machine and machine not in guest.all_machine_names(d):
continue
domains.append(d)
if not domains:
return None
priority = ["kvm", "xen", "qemu"]
for t in priority:
for d in domains:
if d.hypervisor_type == t:
return d
# Fallback, just return last item in list
return domains[-1]
def guest_lookup(self, os_type=None, arch=None, typ=None, machine=None):
"""
Simple virtualization availability lookup
Convenience function for looking up 'Guest' and 'Domain' capabilities
objects for the desired virt type. If type, arch, or os_type are none,
we return the default virt type associated with those values. These are
typically:
- os_type : hvm, then xen
- typ : kvm over plain qemu
- arch : host arch over all others
Otherwise the default will be the first listed in the capabilities xml.
This function throws C{ValueError}s if any of the requested values are
not found.
:param typ: Virtualization type ('hvm', 'xen', ...)
:param arch: Guest architecture ('x86_64', 'i686' ...)
:param os_type: Hypervisor name ('qemu', 'kvm', 'xen', ...)
:param machine: Optional machine type to emulate
:returns: A _CapsInfo object containing the found guest and domain
"""
# F22 libxl xen still puts type=linux in the XML, so we need
# to handle it for caps lookup
if os_type == "linux":
os_type = "xen"
guest = self._guestForOSType(os_type, arch)
if not guest:
archstr = _("for arch '%s'") % arch
if not arch:
archstr = ""
osstr = _("virtualization type '%s'") % os_type
if not os_type:
osstr = _("any virtualization options")
raise ValueError(_("Host does not support %(virttype)s %(arch)s") %
{'virttype': osstr, 'arch': archstr})
domain = self._bestDomainType(guest, typ, machine)
if domain is None:
machinestr = " with machine '%s'" % machine
if not machine:
machinestr = ""
raise ValueError(_("Host does not support domain type %(domain)s"
"%(machine)s for virtualization type "
"'%(virttype)s' arch '%(arch)s'") %
{'domain': typ, 'virttype': guest.os_type,
'arch': guest.arch, 'machine': machinestr})
capsinfo = _CapsInfo(self.conn, guest, domain)
return capsinfo