[Kimchi-devel] [PATCH v6 3/4] Host device passthrough: Directly assign and dissmis host device from VM
Zhou Zheng Sheng
zhshzhou at linux.vnet.ibm.com
Mon Jun 9 09:28:36 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.
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.
Signed-off-by: Zhou Zheng Sheng <zhshzhou at linux.vnet.ibm.com>
---
src/kimchi/control/vm/hostdevs.py | 44 ++++++
src/kimchi/featuretests.py | 10 +-
src/kimchi/i18n.py | 7 +
src/kimchi/model/config.py | 2 +
src/kimchi/model/vmhostdevs.py | 303 ++++++++++++++++++++++++++++++++++++++
src/kimchi/rollbackcontext.py | 3 +
6 files changed, 368 insertions(+), 1 deletion(-)
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..81fe8ec
--- /dev/null
+++ b/src/kimchi/control/vm/hostdevs.py
@@ -0,0 +1,44 @@
+#
+# 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.info = {}
+ 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 5192361..74222bf 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 452ede2..4757001 100644
--- a/src/kimchi/i18n.py
+++ b/src/kimchi/i18n.py
@@ -90,6 +90,13 @@ messages = {
"KCHVM0029E": _("Unable to shutdown virtual machine %(name)s. Details: %(err)s"),
"KCHVM0030E": _("Unable to get access metadata of virtual machine %(name)s. Details: %(err)s"),
+ "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 0ef0855..95c8e7e 100644
--- a/src/kimchi/model/config.py
+++ b/src/kimchi/model/config.py
@@ -54,6 +54,7 @@ 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
@@ -67,6 +68,7 @@ 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']:
diff --git a/src/kimchi/model/vmhostdevs.py b/src/kimchi/model/vmhostdevs.py
new file mode 100644
index 0000000..9e59513
--- /dev/null
+++ b/src/kimchi/model/vmhostdevs.py
@@ -0,0 +1,303 @@
+#
+# 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 libvirt
+from lxml import etree, objectify
+
+from kimchi.exception import InvalidOperation, InvalidParameter, NotFoundError
+from kimchi.model.config import CapabilitiesModel
+from kimchi.model.host import DeviceModel, DevicesModel
+from kimchi.model.host import PassthroughAffectedDevicesModel
+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):
+ dev_types = {
+ 'pci': self._deduce_dev_name_pci,
+ 'scsi': self._deduce_dev_name_scsi,
+ 'usb': self._deduce_dev_name_usb,
+ }
+ return dev_types[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 = {
+ 'pci': self._attach_pci_device,
+ 'scsi': self._attach_scsi_device,
+ 'usb_device': self._attach_usb_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'
+
+ xmlstr = '''
+ <hostdev mode='subsystem' type='pci' managed='yes'>
+ <source>
+ <address domain='%(domain)s' bus='%(bus)s' slot='%(slot)s'
+ function='%(function)s'/>
+ </source>
+ <driver name='%(detach_driver)s'/>
+ </hostdev>''' % dev_info
+ return xmlstr
+
+ @staticmethod
+ def _validate_pci_passthrough_env():
+ 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)
+ affected_devs_model = PassthroughAffectedDevicesModel(conn=self.conn)
+ dev_infos = [dev_model.lookup(dev_name) for dev_name in
+ affected_devs_model.get_list(dev_info['name'])]
+ pci_infos = [dev_info] + [info for info in dev_infos
+ if info['device_type'] == 'pci']
+
+ 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):
+ xmlstr = '''
+ <hostdev mode='subsystem' type='scsi' sgio='unfiltered'>
+ <source>
+ <adapter name='scsi_host%(host)s'/>
+ <address type='scsi' bus='%(bus)s' target='%(target)s'
+ unit='%(lun)s'/>
+ </source>
+ </hostdev>''' % dev_info
+ return xmlstr
+
+ 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):
+ xmlstr = '''
+ <hostdev mode='subsystem' type='usb' managed='yes'>
+ <source startupPolicy='optional'>
+ <vendor id='%s'/>
+ <product id='%s'/>
+ <address bus='%s' device='%s'/>
+ </source>
+ </hostdev>''' % (dev_info['vendor']['id'], dev_info['product']['id'],
+ dev_info['bus'], dev_info['device'])
+ return xmlstr
+
+ 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)
+ pci_devs = []
+
+ 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 e.attrib['type'] == 'pci':
+ pci_devs.append((deduced_name, e))
+ if deduced_name == dev_name:
+ dev_e = e
+ xmlstr = etree.tostring(e)
+ dom.detachDeviceFlags(
+ xmlstr, get_vm_config_flag(dom, mode='all'))
+ break
+ else:
+ raise NotFoundError('KCHVMHDEV0001E',
+ {'vmid': vmid, 'dev_name': dev_name})
+
+ if dev_e.attrib['type'] == 'pci':
+ self._delete_affected_pci_devices(dom, dev_name, pci_devs)
+
+ 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(
+ PassthroughAffectedDevicesModel(conn=self.conn).get_list(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 70fcfeb..ba28999 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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