[Kimchi-devel] [PATCH v6 2/4] Host device passthrough: List eligible device to passthrough
Sheldon
shaohef at linux.vnet.ibm.com
Tue Jun 10 14:48:29 UTC 2014
Reviewed-by: ShaoHe Feng <shaohef at linux.vnet.ibm.com>
looks good for me after with zhengsheng.
On 06/09/2014 05:28 PM, Zhou Zheng Sheng wrote:
> This patch adds a '_passthrough=1' filter to /host/devices, so it can
> filter and shows all devices eligible to passthrough to guest.
> Theoretically, all PCI, USB and SCSI devices can be assigned to guest
> directly. However usually all host devices form a tree, if we assign a
> PCI port/SCSI controller/USB controller to guest, all devices/disks
> under the controller are assigned as well. In this patch we only present
> the "leaf" host devices to the user as potential passthrough devices.
> In other word, the possible devices are wireless network interface, SD
> card reader, camera, SCSI unit(disk or CD), and so on.
>
> Linux kernel is able to recognize the host IOMMU group layout. If two
> PCI devices are in the same IOMMU group, it means there are possible
> interconnections between the devices, and the devices can talk to each
> other bypassing IOMMU. This implies isolation is not pefect between those
> devices, so all devices in a IOMMU group must be assigned to guest
> together. On host that recognizes IOMMU groups, by accessing the URI
> /host/devices/deviceX/passthrough_affected_devices, it returns a list
> containing the devices in the same IOMMU group as deviceX.
>
> How to test:
>
> List all types of devices to passthrough
> curl -k -u root -H "Content-Type: application/json" \
> -H "Accept: application/json" \
> 'https://127.0.0.1:8001/host/devices?_passthrough=true'
>
> List all eligible PCI devices to passthrough
> /host/devices?_passthrough=true&_cap=pci
>
> List all USB devices to passthrough
> /host/devices?_passthrough=true&_cap=usb_device
>
> List all SCSI devices to passthrough
> /host/devices?_passthrough=true&_cap=scsi
>
> List devices in the same IOMMU group as pci_0000_00_19_0
> /host/devices/pci_0000_00_19_0/passthrough_affected_devices
>
> v1:
> v1 series does not contain this patch.
>
> v2:
> Deal with calculation "leaf" device and "affected" device.
>
> v3 v4:
> No change.
>
> v5:
> Change _passthrough=1 to _passthrough=true in the URI scheme. Filter
> PCI devices according the PCI class.
>
> v6:
> Don't passthrough PCI device of class code 07. In modern
> x86 machine, it's possible that
> "6 Series/C200 Series Chipset Family MEI Controller" and
> "6 Series/C200 Series Chipset Family KT Controller"
> are of this class code. These two devices are not suitable to
> passthrough to guest. We don't have simple and reliable way to
> distinguish normal serial controller and host chipset XXX controller.
> This type of PCI devices also include various serial, parallel, modem,
> communication controller. Serial and parallel controllers can be
> re-direct from ttyS0 to QEMU's pty using socat, and there is little
> performance benefit to directly assign to guest. So it'k ok not to
> passththrough PCI device of class code 07.
>
> Signed-off-by: Zhou Zheng Sheng <zhshzhou at linux.vnet.ibm.com>
> ---
> src/kimchi/control/host.py | 9 ++++
> src/kimchi/hostdev.py | 107 +++++++++++++++++++++++++++++++++++++++++++++
> src/kimchi/model/host.py | 17 ++++++-
> 3 files changed, 132 insertions(+), 1 deletion(-)
>
> diff --git a/src/kimchi/control/host.py b/src/kimchi/control/host.py
> index ebf1bed..15f2343 100644
> --- a/src/kimchi/control/host.py
> +++ b/src/kimchi/control/host.py
> @@ -103,9 +103,18 @@ class Devices(Collection):
> self.resource = Device
>
>
> +class PassthroughAffectedDevices(Collection):
> + def __init__(self, model, device_id):
> + super(PassthroughAffectedDevices, self).__init__(model)
> + self.resource = Device
> + self.model_args = (device_id, )
> +
> +
> class Device(Resource):
> def __init__(self, model, id):
> super(Device, self).__init__(model, id)
> + self.passthrough_affected_devices = \
> + PassthroughAffectedDevices(self.model, id)
>
> @property
> def data(self):
> diff --git a/src/kimchi/hostdev.py b/src/kimchi/hostdev.py
> index d4c142d..f70154f 100644
> --- a/src/kimchi/hostdev.py
> +++ b/src/kimchi/hostdev.py
> @@ -17,6 +17,8 @@
> # 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 os
> +
> from kimchi.model.libvirtconnection import LibvirtConnection
> from kimchi.utils import kimchi_log
> from kimchi.xmlutils import dictize
> @@ -46,6 +48,108 @@ def _get_dev_info_tree(dev_infos):
> return root
>
>
> +def _strip_parents(devs, dev):
> + parent = dev['parent']
> + while parent is not None:
> + try:
> + parent_dev = devs.pop(parent)
> + except KeyError:
> + break
> +
> + if (parent_dev['device_type'],
> + dev['device_type']) == ('usb_device', 'scsi'):
> + # For USB device containing mass storage, passthrough the
> + # USB device itself, not the SCSI unit.
> + devs.pop(dev['name'])
> + break
> +
> + parent = parent_dev['parent']
> +
> +
> +def _is_pci_qualified(pci_dev):
> + # PCI class such as bridge and storage controller are not suitable to
> + # passthrough to VM, so we make a whitelist and only passthrough PCI
> + # class in the list.
> +
> + whitelist_pci_classes = {
> + # Refer to Linux Kernel code include/linux/pci_ids.h
> + 0x000000: { # Old PCI devices
> + 0x000100: None}, # Old VGA devices
> + 0x020000: None, # Network controller
> + 0x030000: None, # Display controller
> + 0x040000: None, # Multimedia device
> + 0x090000: None, # Inupt device
> + 0x0d0000: None, # Wireless controller
> + 0x0f0000: None, # Satellite communication controller
> + 0x100000: None, # Cryption controller
> + 0x110000: None, # Signal Processing controller
> + }
> +
> + with open(os.path.join(pci_dev['path'], 'class')) as f:
> + pci_class = int(f.read(), 16)
> +
> + try:
> + subclass = whitelist_pci_classes[pci_class & 0xff0000]
> + except KeyError:
> + return False
> +
> + if subclass is None:
> + return True
> +
> + if pci_class & 0xffff00 in subclass:
> + return True
> +
> + return False
> +
> +
> +def get_passthrough_dev_infos():
> + ''' Get devices eligible to be passed through to VM. '''
> +
> + dev_infos = _get_all_host_dev_infos()
> + devs = dict([(dev_info['name'], dev_info) for dev_info in dev_infos])
> +
> + for dev in dev_infos:
> + if dev['device_type'] in ('pci', 'usb_device', 'scsi'):
> + _strip_parents(devs, dev)
> +
> + def is_eligible(dev):
> + if dev['device_type'] not in ('pci', 'usb_device', 'scsi'):
> + return False
> + if dev['device_type'] == 'pci':
> + return _is_pci_qualified(dev)
> + return True
> +
> + return [dev for dev in devs.itervalues() if is_eligible(dev)]
> +
> +
> +def get_affected_passthrough_devices(passthrough_dev):
> + devs = dict([(dev['name'], dev) for dev in _get_all_host_dev_infos()])
> +
> + def get_iommu_group(dev_info):
> + try:
> + return int(dev_info['iommuGroup'])
> + except KeyError:
> + pass
> +
> + parent = dev_info['parent']
> + while parent is not None:
> + try:
> + iommuGroup = int(devs[parent]['iommuGroup'])
> + except KeyError:
> + pass
> + else:
> + return iommuGroup
> + parent = devs[parent]['parent']
> +
> + return -1
> +
> + iommu_group = get_iommu_group(passthrough_dev)
> +
> + return [dev for dev in get_passthrough_dev_infos()
> + if dev['name'] != passthrough_dev['name'] and
> + get_iommu_group(dev) == iommu_group]
> +
> +
> def get_dev_info(node_dev):
> ''' Parse the node device XML string into dict according to
> http://libvirt.org/formatnode.html. '''
> @@ -206,4 +310,7 @@ def _format_dev_node(node):
>
>
> if __name__ == '__main__':
> + from pprint import pprint
> _print_host_dev_tree()
> + print 'Eligible passthrough devices:'
> + pprint(get_passthrough_dev_infos())
> diff --git a/src/kimchi/model/host.py b/src/kimchi/model/host.py
> index 1ea97f0..280aa53 100644
> --- a/src/kimchi/model/host.py
> +++ b/src/kimchi/model/host.py
> @@ -247,7 +247,7 @@ class DevicesModel(object):
> def __init__(self, **kargs):
> self.conn = kargs['conn']
>
> - def get_list(self, _cap=None):
> + def get_list(self, _cap=None, _passthrough=None):
> conn = self.conn.get()
> if _cap is None:
> dev_names = [name.name() for name in conn.listAllDevices(0)]
> @@ -256,6 +256,11 @@ class DevicesModel(object):
> else:
> # Get devices with required capability
> dev_names = conn.listDevices(_cap, 0)
> +
> + if _passthrough is not None and _passthrough.lower() == 'true':
> + passthrough_names = [
> + dev['name'] for dev in hostdev.get_passthrough_dev_infos()]
> + dev_names = list(set(dev_names) & set(passthrough_names))
> return dev_names
>
> def _get_devices_fc_host(self):
> @@ -273,6 +278,16 @@ class DevicesModel(object):
> return conn.listDevices('fc_host', 0)
>
>
> +class PassthroughAffectedDevicesModel(object):
> + def __init__(self, **kargs):
> + self.conn = kargs['conn']
> +
> + def get_list(self, device_id):
> + dev_info = DeviceModel(conn=self.conn).lookup(device_id)
> + affected = hostdev.get_affected_passthrough_devices(dev_info)
> + return [dev['name'] for dev in affected]
> +
> +
> class DeviceModel(object):
> def __init__(self, **kargs):
> self.conn = kargs['conn']
--
Thanks and best regards!
Sheldon Feng(冯少合)<shaohef at linux.vnet.ibm.com>
IBM Linux Technology Center
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