[Kimchi-devel] [PATCH 3/6 - V2] [Memory HotPlug] Memory device control and model classes

[Rodrigo Trujillo]

This patch creates new colletion and resource of memory devices. They
are subnodes of a given VM resource, that means the user is going to use
the VM url/api to add or fetch the memory devices, such as:
http://<HOST>/vms/<YOUR_VM>/memdevices (GET)  -> to list memory devs
http://<HOST>/vms/<YOUR_VM>/memdevices (POST) -> to add a memory dev
http://<HOST>/vms/<YOUR_VM>/memdevices/<SLOT> (GET) -> to retrieve a
given memory device in SLOT
This patch does not give support do DELETE or UPDATE a memory device

Signed-off-by: Rodrigo Trujillo <rodrigo.trujillo at linux.vnet.ibm.com>
---
 src/kimchi/control/vm/memdevices.py | 47 +++++++++++++++++++
 src/kimchi/i18n.py                  |  2 +
 src/kimchi/model/vmmemdevices.py    | 94 +++++++++++++++++++++++++++++++++++++
 3 files changed, 143 insertions(+)
 create mode 100644 src/kimchi/control/vm/memdevices.py
 create mode 100644 src/kimchi/model/vmmemdevices.py

diff --git a/src/kimchi/control/vm/memdevices.py b/src/kimchi/control/vm/memdevices.py
new file mode 100644
index 0000000..2d96104
--- /dev/null
+++ b/src/kimchi/control/vm/memdevices.py
@@ -0,0 +1,47 @@
+#
+# Project Kimchi
+#
+# Copyright IBM, Corp. 2015
+#
+# 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("memdevices")
+class VMMemDevices(Collection):
+    def __init__(self, model, vm):
+        super(VMMemDevices, self).__init__(model)
+        self.admin_methods = ['GET', 'POST']
+        self.resource = VMMemDevice
+        self.vm = vm
+        self.resource_args = [self.vm, ]
+        self.model_args = [self.vm, ]
+
+
+class VMMemDevice(Resource):
+    def __init__(self, model, vm, ident):
+        super(VMMemDevice, self).__init__(model, ident)
+        self.admin_methods = ['GET']
+        self.vm = vm
+        self.ident = ident
+        self.info = {}
+        self.model_args = [self.vm, self.ident]
+        self.uri_fmt = '/vms/%s/memdevices/%s'
+
+    @property
+    def data(self):
+        return self.info
diff --git a/src/kimchi/i18n.py b/src/kimchi/i18n.py
index 9f169ab..7085530 100644
--- a/src/kimchi/i18n.py
+++ b/src/kimchi/i18n.py
@@ -340,4 +340,6 @@ messages = {
     "KCHCPUINF0002E": _("Invalid vCPU/topology combination."),
     "KCHCPUINF0003E": _("This host (or current configuration) does not allow CPU topology."),
 
+    "KCHMEMDEV0001E": _("Host's libvirt version does not support memory devices. Libvirt must be >= 1.2.14"),
+    "KCHMEMDEV0002E": _("Error attaching memory device. Details: %(error)s"),
 }
diff --git a/src/kimchi/model/vmmemdevices.py b/src/kimchi/model/vmmemdevices.py
new file mode 100644
index 0000000..c92678d
--- /dev/null
+++ b/src/kimchi/model/vmmemdevices.py
@@ -0,0 +1,94 @@
+#
+# Project Kimchi
+#
+# Copyright IBM, Corp. 2015
+#
+# 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 libvirt import VIR_DOMAIN_MEM_CONFIG, VIR_DOMAIN_MEM_LIVE
+from lxml import etree, objectify
+from lxml.builder import E
+
+
+from kimchi.exception import InvalidOperation, OperationFailed
+from kimchi.model.config import CapabilitiesModel
+
+
+def _get_all_memory_devices(conn, vm_name):
+    # Return all memory devices from a given guest
+    dom = conn.get().lookupByName(vm_name)
+    devs = objectify.fromstring(dom.XMLDesc(0)).devices
+    return devs.findall('memory')
+
+
+class VMMemDevicesModel(object):
+    def __init__(self, **kargs):
+        self.conn = kargs['conn']
+        self.objstore = kargs['objstore']
+        self.caps = CapabilitiesModel(**kargs)
+
+    def create(self, vm_name, params):
+        # Check if host supports memory device
+        if not self.caps.mem_hotplug_support:
+            raise InvalidOperation("KCHMEMDEV0001E")
+
+        dom = self.conn.get().lookupByName(vm_name)
+        # Setting flags, depending if machine is running or not
+        flags = VIR_DOMAIN_MEM_CONFIG
+        if dom.isActive():
+            flags = flags | VIR_DOMAIN_MEM_LIVE
+
+        # Create memory device xml
+        mem_dev_xml = etree.tostring(
+            E.memory(
+                E.target(
+                    E.size('1', unit='GiB'),
+                    E.node('0')),
+                model='dimm'
+            )
+        )
+        # Add chunks of 1G of memory
+        for i in range(params['amount']):
+            try:
+                dom.attachDeviceFlags(mem_dev_xml, flags)
+            except Exception as e:
+                raise OperationFailed("KCHMEMDEV0002E", {'error': e.message})
+        return len(_get_all_memory_devices(self.conn, vm_name)) - 1
+
+    def get_list(self, vm_name):
+        # Memory devices do not have an ID or something similar in the XML, so
+        # lets return the positions of all memory devices in the XML.
+        return [str(i) for i in range(len(
+            _get_all_memory_devices(self.conn, vm_name)))]
+
+
+class VMMemDeviceModel(object):
+    def __init__(self, **kargs):
+        self.conn = kargs['conn']
+        self.objstore = kargs['objstore']
+        self.caps = CapabilitiesModel(**kargs)
+
+    def lookup(self, vm_name, dev_slot):
+        # We are considering the memory device position in the XML, which
+        # can also be considered the slot position
+        try:
+            memdev = _get_all_memory_devices(self.conn, vm_name)[int(dev_slot)]
+            return {
+                'slot': dev_slot,
+                'size': str(memdev.xpath('./target/size')[0] >> 20) + 'G',
+                'node': str(memdev.xpath('./target/node')[0])
+            }
+        except IndexError:
+            return {}
-- 
2.1.0