[Kimchi-devel] [PATCH v12 3/6] Host device passthrough: Directly assign and dissmis host device from VM
Zhou Zheng Sheng
zhshzhou at linux.vnet.ibm.com
Wed Oct 8 09:08:40 UTC 2014
This patch enbales Kimchi's VM to use host devices directly, and it
greatly improves the related device performance. The user can assign
PCI, USB and SCSI LUN directly to VM, as long as the host supports one
of Intel VT-d, AMD IOMMU or POWER sPAPR technology and runs a recent
release of Linux kernel.
This patch adds a sub-collection "hostdevs" to the URI vms/vm-name/.
The front-end can GET
vms/vm-name/hostdevs
and
vms/vm-name/hostdevs/dev-name
or POST (assign)
vms/vm-name/hostdevs
and DELETE (dismiss)
vms/vm-name/hostdevs/dev-name
The eligible devices to assign are the devices listed by the URI
host/devices?_passthrough=1
When assigning a host PCI device to VM, all the eligible PCI devices in
the same IOMMU group are also automatically assigned, and vice versa
when dismissing a host PIC device from the VM.
Some examples:
Assign a USB device:
curl -k -u root -H "Content-Type: application/json" \
-H "Accept: application/json" \
-X POST -d '{"name": "usb_1_1_6"}' \
'https://127.0.0.1:8001/vms/rhel65/hostdevs'
Assign a PCI device:
-d '{"name": "pci_0000_0d_00_0"}'
Assign a SCSI LUN:
-d '{"name": "scsi_1_0_0_0"}'
List assigned devices:
curl -k -u root -H "Content-Type: application/json" \
-H "Accept: application/json" \
'https://127.0.0.1:8001/vms/rhel65/hostdevs'
The above command should print following.
[
{
"type":"scsi",
"name":"scsi_1_0_0_0"
},
{
"type":"usb",
"name":"usb_1_1_6"
},
{
"type":"pci",
"name":"pci_0000_0d_00_0"
},
{
"type":"pci",
"name":"pci_0000_03_00_0"
}
]
Notice that the device pci_0000_03_00_0 is also assigned automatically.
The assigned devices are hot-plugged to VM and also written to the
domain XML. When it's possible, it enables VFIO for PCI device
assignment.
On distribution with old Linux kernel, there are many limitations with
PCI passthrough and it's hardly useful. This patch tries to adapt to old
kernel but it's better to use a newer kernel with vfio support. Thus
this patch also provide a new capability in /config/capabilities. The
front-end can disable or freeze the related web UI if back-end reports
host does not support vfio.
curl -k -u root -H "Content-Type: application/json" \
-H "Accept: application/json" \
'https://127.0.0.1:8001/config/capabilities'
The above command should print following.
{
"blah": "blah",
...
"kernel_vfio":true
}
v1:
Handle the devices in the VM template.
v2:
Handle the devices in the VM sub-resource "hostdevs".
v3:
No change.
v4:
Not all domain XMLs contain hostdev node. Deal with the case.
v5:
Change _passthrough='1' to _passthrough='true'. When attaching and
detaching a device, do not use VIR_DOMAIN_AFFECT_CURRENT flag, instead,
use kimchi.model.utils.get_vm_config_flag() to correctly set the device
flag.
v11:
Add Capability kernel_vfio to indicate if Linux kernel is new enough
to support vfio.
v12:
Use lxml.etree and lxml.builder to generate XML.
Signed-off-by: Zhou Zheng Sheng <zhshzhou at linux.vnet.ibm.com>
---
src/kimchi/control/vm/hostdevs.py | 43 ++++++
src/kimchi/featuretests.py | 10 +-
src/kimchi/i18n.py | 7 +
src/kimchi/model/config.py | 6 +-
src/kimchi/model/vmhostdevs.py | 295 ++++++++++++++++++++++++++++++++++++++
src/kimchi/rollbackcontext.py | 3 +
6 files changed, 362 insertions(+), 2 deletions(-)
create mode 100644 src/kimchi/control/vm/hostdevs.py
create mode 100644 src/kimchi/model/vmhostdevs.py
diff --git a/src/kimchi/control/vm/hostdevs.py b/src/kimchi/control/vm/hostdevs.py
new file mode 100644
index 0000000..1eb88cf
--- /dev/null
+++ b/src/kimchi/control/vm/hostdevs.py
@@ -0,0 +1,43 @@
+#
+# Project Kimchi
+#
+# Copyright IBM, Corp. 2014
+#
+# 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, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+
+from kimchi.control.base import Collection, Resource
+from kimchi.control.utils import UrlSubNode
+
+
+ at UrlSubNode("hostdevs")
+class VMHostDevs(Collection):
+ def __init__(self, model, vmid):
+ super(VMHostDevs, self).__init__(model)
+ self.resource = VMHostDev
+ self.vmid = vmid
+ self.resource_args = [self.vmid, ]
+ self.model_args = [self.vmid, ]
+
+
+class VMHostDev(Resource):
+ def __init__(self, model, vmid, ident):
+ super(VMHostDev, self).__init__(model, ident)
+ self.vmid = vmid
+ self.ident = ident
+ self.model_args = [self.vmid, self.ident]
+
+ @property
+ def data(self):
+ return self.info
diff --git a/src/kimchi/featuretests.py b/src/kimchi/featuretests.py
index 8964098..c1470fc 100644
--- a/src/kimchi/featuretests.py
+++ b/src/kimchi/featuretests.py
@@ -29,7 +29,7 @@ from lxml.builder import E
from kimchi.rollbackcontext import RollbackContext
-from kimchi.utils import kimchi_log
+from kimchi.utils import kimchi_log, run_command
ISO_STREAM_XML = """
@@ -206,3 +206,11 @@ class FeatureTests(object):
return True
except libvirt.libvirtError:
return False
+
+ @staticmethod
+ def kernel_support_vfio():
+ out, err, rc = run_command(['modprobe', 'vfio-pci'])
+ if rc != 0:
+ kimchi_log.warning("Unable to load Kernal module vfio-pci.")
+ return False
+ return True
diff --git a/src/kimchi/i18n.py b/src/kimchi/i18n.py
index 98adc46..ad65775 100644
--- a/src/kimchi/i18n.py
+++ b/src/kimchi/i18n.py
@@ -98,6 +98,13 @@ messages = {
"KCHVM0031E": _("The guest console password must be a string."),
"KCHVM0032E": _("The life time for the guest console password must be a number."),
+ "KCHVMHDEV0001E": _("VM %(vmid)s does not contain directly assigned host device %(dev_name)s."),
+ "KCHVMHDEV0002E": _("The host device %(dev_name)s is not allowed to directly assign to VM."),
+ "KCHVMHDEV0003E": _("No IOMMU groups found. Host PCI pass through needs IOMMU group to function correctly. "
+ "Please enable Intel VT-d or AMD IOMMU in your BIOS, then verify the Kernel is compiled with IOMMU support. "
+ "For Intel CPU, add intel_iommu=on to your Kernel parameter in /boot/grub2/grub.conf. "
+ "For AMD CPU, add iommu=pt iommu=1."),
+
"KCHVMIF0001E": _("Interface %(iface)s does not exist in virtual machine %(name)s"),
"KCHVMIF0002E": _("Network %(network)s specified for virtual machine %(name)s does not exist"),
"KCHVMIF0003E": _("Do not support guest interface hot plug attachment"),
diff --git a/src/kimchi/model/config.py b/src/kimchi/model/config.py
index 1c00cfe..9ffc53e 100644
--- a/src/kimchi/model/config.py
+++ b/src/kimchi/model/config.py
@@ -53,6 +53,7 @@ class CapabilitiesModel(object):
self.libvirt_stream_protocols = []
self.fc_host_support = False
self.metadata_support = False
+ self.kernel_vfio = False
# Subscribe function to set host capabilities to be run when cherrypy
# server is up
@@ -66,6 +67,7 @@ class CapabilitiesModel(object):
self.nfs_target_probe = FeatureTests.libvirt_support_nfs_probe()
self.fc_host_support = FeatureTests.libvirt_support_fc_host()
self.metadata_support = FeatureTests.has_metadata_support()
+ self.kernel_vfio = FeatureTests.kernel_support_vfio()
self.libvirt_stream_protocols = []
for p in ['http', 'https', 'ftp', 'ftps', 'tftp']:
@@ -110,7 +112,9 @@ class CapabilitiesModel(object):
'system_report_tool': bool(report_tool),
'update_tool': update_tool,
'repo_mngt_tool': repo_mngt_tool,
- 'federation': kconfig.get("server", "federation")}
+ 'federation': kconfig.get("server", "federation"),
+ 'kernel_vfio': self.kernel_vfio,
+ }
class DistrosModel(object):
diff --git a/src/kimchi/model/vmhostdevs.py b/src/kimchi/model/vmhostdevs.py
new file mode 100644
index 0000000..d9e7a05
--- /dev/null
+++ b/src/kimchi/model/vmhostdevs.py
@@ -0,0 +1,295 @@
+#
+# Project Kimchi
+#
+# Copyright IBM, Corp. 2014
+#
+# 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, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+
+import glob
+import os
+
+import libvirt
+from lxml import etree, objectify
+from lxml.builder import E
+
+from kimchi.exception import InvalidOperation, InvalidParameter, NotFoundError
+from kimchi.model.config import CapabilitiesModel
+from kimchi.model.host import DeviceModel, DevicesModel
+from kimchi.model.utils import get_vm_config_flag
+from kimchi.model.vms import DOM_STATE_MAP, VMModel
+from kimchi.rollbackcontext import RollbackContext
+from kimchi.utils import kimchi_log, run_command
+
+
+class VMHostDevsModel(object):
+ def __init__(self, **kargs):
+ self.conn = kargs['conn']
+
+ def get_list(self, vmid):
+ dom = VMModel.get_vm(vmid, self.conn)
+ xmlstr = dom.XMLDesc(0)
+ root = objectify.fromstring(xmlstr)
+ try:
+ hostdev = root.devices.hostdev
+ except AttributeError:
+ return []
+
+ return [self._deduce_dev_name(e) for e in hostdev]
+
+ @staticmethod
+ def _toint(num_str):
+ if num_str.startswith('0x'):
+ return int(num_str, 16)
+ elif num_str.startswith('0'):
+ return int(num_str, 8)
+ else:
+ return int(num_str)
+
+ def _deduce_dev_name(self, e):
+ return getattr(self, '_deduce_dev_name_%s' % e.attrib['type'])(e)
+
+ def _deduce_dev_name_pci(self, e):
+ attrib = {}
+ for field in ('domain', 'bus', 'slot', 'function'):
+ attrib[field] = self._toint(e.source.address.attrib[field])
+ return 'pci_%(domain)04x_%(bus)02x_%(slot)02x_%(function)x' % attrib
+
+ def _deduce_dev_name_scsi(self, e):
+ attrib = {}
+ for field in ('bus', 'target', 'unit'):
+ attrib[field] = self._toint(e.source.address.attrib[field])
+ attrib['host'] = self._toint(
+ e.source.adapter.attrib['name'][len('scsi_host'):])
+ return 'scsi_%(host)d_%(bus)d_%(target)d_%(unit)d' % attrib
+
+ def _deduce_dev_name_usb(self, e):
+ dev_names = DevicesModel(conn=self.conn).get_list(_cap='usb_device')
+ usb_infos = [DeviceModel(conn=self.conn).lookup(dev_name)
+ for dev_name in dev_names]
+
+ unknown_dev = None
+
+ try:
+ evendor = self._toint(e.source.vendor.attrib['id'])
+ eproduct = self._toint(e.source.product.attrib['id'])
+ except AttributeError:
+ evendor = 0
+ eproduct = 0
+ else:
+ unknown_dev = 'usb_vendor_%s_product_%s' % (evendor, eproduct)
+
+ try:
+ ebus = self._toint(e.source.address.attrib['bus'])
+ edevice = self._toint(e.source.address.attrib['device'])
+ except AttributeError:
+ ebus = -1
+ edevice = -1
+ else:
+ unknown_dev = 'usb_bus_%s_device_%s' % (ebus, edevice)
+
+ for usb_info in usb_infos:
+ ivendor = self._toint(usb_info['vendor']['id'])
+ iproduct = self._toint(usb_info['product']['id'])
+ if evendor == ivendor and eproduct == iproduct:
+ return usb_info['name']
+ ibus = usb_info['bus']
+ idevice = usb_info['device']
+ if ebus == ibus and edevice == idevice:
+ return usb_info['name']
+ return unknown_dev
+
+ def _passthrough_device_validate(self, dev_name):
+ eligible_dev_names = \
+ DevicesModel(conn=self.conn).get_list(_passthrough='true')
+ if dev_name not in eligible_dev_names:
+ raise InvalidParameter('KCHVMHDEV0002E', {'dev_name': dev_name})
+
+ def create(self, vmid, params):
+ dev_name = params['name']
+ self._passthrough_device_validate(dev_name)
+ dev_info = DeviceModel(conn=self.conn).lookup(dev_name)
+ attach_device = getattr(
+ self, '_attach_%s_device' % dev_info['device_type'])
+ return attach_device(vmid, dev_info)
+
+ def _get_pci_device_xml(self, dev_info):
+ if 'detach_driver' not in dev_info:
+ dev_info['detach_driver'] = 'kvm'
+
+ source = E.source(E.address(domain=str(dev_info['domain']),
+ bus=str(dev_info['bus']),
+ slot=str(dev_info['slot']),
+ function=str(dev_info['function'])))
+ driver = E.driver(name=dev_info['detach_driver'])
+ host_dev = E.hostdev(source, driver,
+ mode='subsystem', type='pci', managed='yes')
+
+ return etree.tostring(host_dev)
+
+ @staticmethod
+ def _validate_pci_passthrough_env():
+ # Linux kernel < 3.5 doesn't provide /sys/kernel/iommu_groups
+ if os.path.isdir('/sys/kernel/iommu_groups'):
+ if not glob.glob('/sys/kernel/iommu_groups/*'):
+ raise InvalidOperation("KCHVMHDEV0003E")
+
+ # Enable virt_use_sysfs on RHEL6 and older distributions
+ # In recent Fedora, there is no virt_use_sysfs.
+ out, err, rc = run_command(['getsebool', 'virt_use_sysfs'])
+ if rc == 0 and out.rstrip('\n') != "virt_use_sysfs --> on":
+ out, err, rc = run_command(['setsebool', '-P',
+ 'virt_use_sysfs=on'])
+ if rc != 0:
+ kimchi_log.warning("Unable to turn on sebool virt_use_sysfs")
+
+ def _attach_pci_device(self, vmid, dev_info):
+ self._validate_pci_passthrough_env()
+
+ dom = VMModel.get_vm(vmid, self.conn)
+ # Due to libvirt limitation, we don't support live assigne device to
+ # vfio driver.
+ driver = ('vfio' if DOM_STATE_MAP[dom.info()[0]] == "shutoff" and
+ CapabilitiesModel().kernel_vfio else 'kvm')
+
+ # Attach all PCI devices in the same IOMMU group
+ dev_model = DeviceModel(conn=self.conn)
+ devs_model = DevicesModel(conn=self.conn)
+ affected_names = devs_model.get_list(
+ _passthrough_affected_by=dev_info['name'])
+ passthrough_names = devs_model.get_list(
+ _cap='pci', _passthrough='true')
+ group_names = list(set(affected_names) & set(passthrough_names))
+ pci_infos = [dev_model.lookup(dev_name) for dev_name in group_names]
+ pci_infos.append(dev_info)
+
+ device_flags = get_vm_config_flag(dom, mode='all')
+
+ with RollbackContext() as rollback:
+ for pci_info in pci_infos:
+ pci_info['detach_driver'] = driver
+ xmlstr = self._get_pci_device_xml(pci_info)
+ try:
+ dom.attachDeviceFlags(xmlstr, device_flags)
+ except libvirt.libvirtError:
+ kimchi_log.error(
+ 'Failed to attach host device %s to VM %s: \n%s',
+ pci_info['name'], vmid, xmlstr)
+ raise
+ rollback.prependDefer(dom.detachDeviceFlags,
+ xmlstr, device_flags)
+ rollback.commitAll()
+
+ return dev_info['name']
+
+ def _get_scsi_device_xml(self, dev_info):
+ adapter = E.adapter(name=('scsi_host%s' % dev_info['host']))
+ address = E.address(type='scsi', bus=str(dev_info['bus']),
+ target=str(dev_info['target']),
+ unit=str(dev_info['lun']))
+ host_dev = E.hostdev(E.source(adapter, address),
+ mode='subsystem', type='scsi', sgio='unfiltered')
+ return etree.tostring(host_dev)
+
+ def _attach_scsi_device(self, vmid, dev_info):
+ xmlstr = self._get_scsi_device_xml(dev_info)
+ dom = VMModel.get_vm(vmid, self.conn)
+ dom.attachDeviceFlags(xmlstr, get_vm_config_flag(dom, mode='all'))
+ return dev_info['name']
+
+ def _get_usb_device_xml(self, dev_info):
+ source = E.source(
+ E.vendor(id=dev_info['vendor']['id']),
+ E.product(id=dev_info['product']['id']),
+ E.address(bus=str(dev_info['bus']),
+ device=str(dev_info['device'])),
+ startupPolicy='optional')
+ host_dev = E.hostdev(source, mode='subsystem',
+ ype='usb', managed='yes')
+ return etree.tostring(host_dev)
+
+ def _attach_usb_device(self, vmid, dev_info):
+ xmlstr = self._get_usb_device_xml(dev_info)
+ dom = VMModel.get_vm(vmid, self.conn)
+ dom.attachDeviceFlags(xmlstr, get_vm_config_flag(dom, mode='all'))
+ return dev_info['name']
+
+
+class VMHostDevModel(object):
+ def __init__(self, **kargs):
+ self.conn = kargs['conn']
+
+ def lookup(self, vmid, dev_name):
+ dom = VMModel.get_vm(vmid, self.conn)
+ xmlstr = dom.XMLDesc(0)
+ root = objectify.fromstring(xmlstr)
+ try:
+ hostdev = root.devices.hostdev
+ except AttributeError:
+ raise NotFoundError('KCHVMHDEV0001E',
+ {'vmid': vmid, 'dev_name': dev_name})
+
+ devsmodel = VMHostDevsModel(conn=self.conn)
+
+ for e in hostdev:
+ deduced_name = devsmodel._deduce_dev_name(e)
+ if deduced_name == dev_name:
+ return {'name': dev_name, 'type': e.attrib['type']}
+
+ raise NotFoundError('KCHVMHDEV0001E',
+ {'vmid': vmid, 'dev_name': dev_name})
+
+ def delete(self, vmid, dev_name):
+ dom = VMModel.get_vm(vmid, self.conn)
+ xmlstr = dom.XMLDesc(0)
+ root = objectify.fromstring(xmlstr)
+
+ try:
+ hostdev = root.devices.hostdev
+ except AttributeError:
+ raise NotFoundError('KCHVMHDEV0001E',
+ {'vmid': vmid, 'dev_name': dev_name})
+
+ devsmodel = VMHostDevsModel(conn=self.conn)
+ pci_devs = [(devsmodel._deduce_dev_name(e), e) for e in hostdev
+ if e.attrib['type'] == 'pci']
+
+ for e in hostdev:
+ if devsmodel._deduce_dev_name(e) == dev_name:
+ xmlstr = etree.tostring(e)
+ dom.detachDeviceFlags(
+ xmlstr, get_vm_config_flag(dom, mode='all'))
+ if e.attrib['type'] == 'pci':
+ self._delete_affected_pci_devices(dom, dev_name, pci_devs)
+ break
+ else:
+ raise NotFoundError('KCHVMHDEV0001E',
+ {'vmid': vmid, 'dev_name': dev_name})
+
+ def _delete_affected_pci_devices(self, dom, dev_name, pci_devs):
+ dev_model = DeviceModel(conn=self.conn)
+ try:
+ dev_model.lookup(dev_name)
+ except NotFoundError:
+ return
+
+ affected_names = set(
+ DevicesModel(
+ conn=self.conn).get_list(_passthrough_affected_by=dev_name))
+
+ for pci_name, e in pci_devs:
+ if pci_name in affected_names:
+ xmlstr = etree.tostring(e)
+ dom.detachDeviceFlags(
+ xmlstr, get_vm_config_flag(dom, mode='all'))
diff --git a/src/kimchi/rollbackcontext.py b/src/kimchi/rollbackcontext.py
index 29c0235..2f3e8bc 100644
--- a/src/kimchi/rollbackcontext.py
+++ b/src/kimchi/rollbackcontext.py
@@ -64,3 +64,6 @@ class RollbackContext(object):
def prependDefer(self, func, *args, **kwargs):
self._finally.insert(0, (func, args, kwargs))
+
+ def commitAll(self):
+ self._finally = []
--
1.9.3
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