[Kimchi-devel] [PATCH v6 2/4] Host device passthrough: List eligible device to passthrough

[Zhou Zheng Sheng]

on 2014/06/09 23:14, Sheldon wrote:
> On 06/09/2014 05:28 PM, Zhou Zheng Sheng wrote:
>> +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
> looks strange?

So the problem you think here is?

>> +        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]
> does this means dev['name'] and passthrough_dev['name'] in same IOMMU
> group ?

Yes.