[Kimchi-devel] [PATCH v11 4/6] Host device passthrough: List VMs that are holding a host device

[Aline Manera]

Reviewed-by: Aline Manera <alinefm at linux.vnet.ibm.com>

On 09/30/2014 07:00 AM, Zhou Zheng Sheng wrote:
> Add a "vm_holders" sub-collection under host device resource, so the
> front-end can determine if a device is busy or not, and the user can
> know which VMs are holding the device.
>
> This patch scans all VM XML to check if a device is hold by a VM.
>
> Example
>    curl -k -u root -H "Content-Type: application/json" \
>      -H "Accept: application/json" \
>      'https://127.0.0.1:8001/host/devices/usb_1_1_6/vm_holders'
> Should output a list like following.
>    [
>      {
>        "state":"shutoff",
>        "name":"fedora20"
>      },
>      {
>        "state":"running",
>        "name":"f20xfce-slave"
>      }
>    ]
>
> If there is no VM holding the device, it prints an empty list [].
>
> v5:
>    When assigning a device to VM, check if there are other VMs holding
> the device and raise an exception. Move the VMHoldersModel to
> vmhostdevs.py to avoid circular import problem.
>
> v11:
>    Allow Guests to Share a Host PCI Device. A PCI device can be shared
>    by guests, as long as there is only one guest active.
>
> Signed-off-by: Zhou Zheng Sheng <zhshzhou at linux.vnet.ibm.com>
> ---
>   src/kimchi/control/host.py     |  7 +++++++
>   src/kimchi/model/vmhostdevs.py | 19 +++++++++++++++++++
>   2 files changed, 26 insertions(+)
>
> diff --git a/src/kimchi/control/host.py b/src/kimchi/control/host.py
> index 1eb6350..7bcae72 100644
> --- a/src/kimchi/control/host.py
> +++ b/src/kimchi/control/host.py
> @@ -113,11 +113,18 @@ class Devices(Collection):
>           self.resource = Device
>
>
> +class VMHolders(SimpleCollection):
> +    def __init__(self, model, device_id):
> +        super(VMHolders, self).__init__(model)
> +        self.model_args = (device_id, )
> +
> +
>   class Device(Resource):
>       def __init__(self, model, id):
>           self.role_key = 'storage'
>           self.admin_methods = ['GET']
>           super(Device, self).__init__(model, id)
> +        self.vm_holders = VMHolders(self.model, id)
>
>       @property
>       def data(self):
> diff --git a/src/kimchi/model/vmhostdevs.py b/src/kimchi/model/vmhostdevs.py
> index 0d002b5..83755eb 100644
> --- a/src/kimchi/model/vmhostdevs.py
> +++ b/src/kimchi/model/vmhostdevs.py
> @@ -303,3 +303,22 @@ class VMHostDevModel(object):
>                   xmlstr = etree.tostring(e)
>                   dom.detachDeviceFlags(
>                       xmlstr, get_vm_config_flag(dom, mode='all'))
> +
> +
> +class VMHoldersModel(object):
> +    def __init__(self, **kargs):
> +        self.conn = kargs['conn']
> +
> +    def get_list(self, device_id):
> +        devsmodel = VMHostDevsModel(conn=self.conn)
> +
> +        conn = self.conn.get()
> +        doms = conn.listAllDomains(0)
> +
> +        res = []
> +        for dom in doms:
> +            dom_name = dom.name()
> +            if device_id in devsmodel.get_list(dom_name):
> +                state = DOM_STATE_MAP[dom.info()[0]]
> +                res.append({"name": dom_name, "state": state})
> +        return res