[Kimchi-devel] [PATCH v7 1/2] Parts to allow Kimchi to configure the cpu topology.

Aline Manera alinefm at linux.vnet.ibm.com
Mon Nov 24 15:07:15 UTC 2014


On 11/20/2014 06:30 PM, Christy Perez wrote:
> This patch adds a host/cpuinfo API so that the topology can be
> retrieved and then used as a guideline for what is legal
> for this system.
>
> The original plan for this function was to abstract everything
> away from users, but over many iterations, it became clear that
> due to differences in architectures, etc., it is simpler to ask
> a user to input cores and threads for a VM, with a few minimal
> restrictions on threads/core and cores.
>
> As a result, the final version of the patch for the backend
> contains only a small amount of validation for new templates.
>
> Signed-off-by: Christy Perez <christy at linux.vnet.ibm.com>
> ---
>   docs/API.md                   |  24 ++++++++
>   src/kimchi/control/cpuinfo.py |  37 ++++++++++++
>   src/kimchi/control/host.py    |   2 +
>   src/kimchi/i18n.py            |   5 ++
>   src/kimchi/model/cpuinfo.py   | 128 ++++++++++++++++++++++++++++++++++++++++++
>   src/kimchi/model/templates.py |  10 ++--
>   6 files changed, 202 insertions(+), 4 deletions(-)
>   create mode 100644 src/kimchi/control/cpuinfo.py
>   create mode 100644 src/kimchi/model/cpuinfo.py
>
> diff --git a/docs/API.md b/docs/API.md
> index 6c36bb1..d51e763 100644
> --- a/docs/API.md
> +++ b/docs/API.md
> @@ -896,6 +896,30 @@ Contains the host sample data.
>
>   *No actions defined*
>
> +### Resource: HostStats
> +
> +**URI:** /host/cpuinfo
> +
> +The cores and sockets of a hosts's CPU. Useful when sizing VMs to take
> +advantages of the perforamance benefits of SMT (Power) or Hyper-Threading (Intel).
> +
> +**Methods:**
> +
> +* **GET**: Retreives the sockets, cores, and threads values.
> +    * threading_enabled: Whether CPU topology is supported on this system.
> +    * sockets: The number of total sockets on a system.
> +    * cores: The total number of cores per socket.
> +    * threads_per_core: The threads per core.
> +
> +**Actions (PUT):**
> +
> +*No actions defined*
> +
> +**Actions (POST):**
> +
> +*No actions defined*
> +
> +
>   ### Resource: HostStatsHistory
>
>   **URI:** /host/stats/history
> diff --git a/src/kimchi/control/cpuinfo.py b/src/kimchi/control/cpuinfo.py
> new file mode 100644
> index 0000000..415dd3d
> --- /dev/null
> +++ b/src/kimchi/control/cpuinfo.py
> @@ -0,0 +1,37 @@
> +#
> +# 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 Resource
> +
> +
> +class CPUInfo(Resource):
> +    def __init__(self, model):
> +        super(CPUInfo, self).__init__(model)
> +        self.admin_methods = ['GET']
> +        self.role_key = 'host'
> +        self.uri_fmt = "/host/cpuinfo"
> +
> +    @property
> +    def data(self):
> +        return {'threading_enabled': self.info['guest_threads_enabled'],
> +                'sockets': self.info['sockets'],
> +                'cores': self.info['cores_available'],
> +                'threads_per_core': self.info['threads_per_core']
> +                }
> diff --git a/src/kimchi/control/host.py b/src/kimchi/control/host.py
> index 4362da7..9f73653 100644
> --- a/src/kimchi/control/host.py
> +++ b/src/kimchi/control/host.py
> @@ -17,6 +17,7 @@
>   # 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.cpuinfo import CPUInfo
>   from kimchi.control.base import Collection, Resource, SimpleCollection
>   from kimchi.control.utils import UrlSubNode
>   from kimchi.exception import NotFoundError
> @@ -39,6 +40,7 @@ def __init__(self, model, id=None):
>           self.users = Users(self.model)
>           self.groups = Groups(self.model)
>           self.swupdate = self.generate_action_handler_task('swupdate')
> +        self.cpuinfo = CPUInfo(self.model)
>
>       @property
>       def data(self):
> diff --git a/src/kimchi/i18n.py b/src/kimchi/i18n.py
> index 8f6b67e..a836401 100644
> --- a/src/kimchi/i18n.py
> +++ b/src/kimchi/i18n.py
> @@ -318,4 +318,9 @@
>       "KCHSNAP0006E": _("Unable to delete snapshot '%(name)s' on virtual machine '%(vm)s'. Details: %(err)s"),
>       "KCHSNAP0008E": _("Unable to retrieve current snapshot on virtual machine '%(vm)s'. Details: %(err)s"),
>       "KCHSNAP0009E": _("Unable to revert virtual machine '%(vm)s' to snapshot '%(name)s'. Details: %(err)s"),
> +
> +    "KCHCPUINF0001E": _("The number of vCPUs is too large for this system."),
> +    "KCHCPUINF0002E": _("Invalid vCPU/topology combination."),
> +    "KCHCPUINF0003E": _("This host (or current configuration) does not allow CPU topology."),
> +
>   }

> diff --git a/src/kimchi/model/cpuinfo.py b/src/kimchi/model/cpuinfo.py
> new file mode 100644
> index 0000000..fbae6ce
> --- /dev/null
> +++ b/src/kimchi/model/cpuinfo.py
> @@ -0,0 +1,128 @@
> +# 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
> +

Seems there are parts of the license header missing here.

> +import platform
> +
> +from xml.etree import ElementTree as ET
> +
> +from kimchi.exception import InvalidParameter, InvalidOperation
> +from kimchi.utils import kimchi_log, run_command
> +
> +ARCH = 'power' if platform.machine().startswith('ppc') else 'x86'
> +LEGACY_CPU_MAX = 4
> +
> +
> +def get_topo_capabilities(connect):
> +    """
> +    This helper function exists solely to be overridden for
> +    mockmodel tests. Since other modules use getCapabilies(),
> +    it can't be overridden directly.
> +    """
> +    xml = connect.getCapabilities()
> +    capabilities = ET.fromstring(xml)
> +    return capabilities.find('host').find('cpu').find('topology')
> +
> +
> +class CPUInfoModel(object):
> +    """
> +    Get information about a CPU for hyperthreading (on x86)
> +    or SMT (on POWER) for logic when creating templates and VMs.
> +    """
> +
> +    def __init__(self, **kargs):
> +        def set_not_supported():
> +            kimchi_log.info("cpu_info topology not supported.")

> +            self.guest_threads_enabled = False
> +            self.sockets = 0
> +            self.cores_present = 0
> +            self.cores_available = 0
> +            self.cores_per_socket = 0
> +            self.threads_per_core = 0
> +            self.max_threads = 0
> +

You can set those values by default and only change them when needed.

> +        self.conn = kargs['conn']
> +        libvirt_topology = None

> +        try:
> +            connect = self.conn.get()
> +        except Exception as e:
> +            kimchi_log.error("cpuinfo: Unable to get qemu connection: %s"
> +                             % e.message)
> +            set_not_supported()
> +
> +        try:
> +            libvirt_topology = get_topo_capabilities(connect)
> +            if libvirt_topology is None:
> +                set_not_supported()
> +                return
> +        except Exception as e:
> +            kimchi_log.info("Unable to get CPU topology capabilities: %s"
> +                            % e.message)
> +            set_not_supported()
> +            return
> +

Then all that become:

try:
     connect = self.conn.get()
     libvirt_topology = get_topo_capabilities()
except Exception, e:
     kimchi_log.into(....)

> +        if ARCH == 'power':
> +            # IBM PowerPC
> +            self.guest_threads_enabled = True
> +            out, error, rc = run_command(['ppc64_cpu', '--smt'])
> +            if rc or 'on' in out:
> +                # SMT has to be disabled for guest to use threads as CPUs.
> +                # rc is always zero, whether SMT is off or on.
> +                self.guest_threads_enabled = False
> +            out, error, rc = run_command(['ppc64_cpu', '--cores-present'])
> +            if not rc:
> +                self.cores_present = int(out.split()[-1])
> +            out, error, rc = run_command(['ppc64_cpu', '--cores-on'])
> +            if not rc:
> +                self.cores_available = int(out.split()[-1])
> +            out, error, rc = run_command(['ppc64_cpu', '--threads-per-core'])
> +            if not rc:
> +                self.threads_per_core = int(out.split()[-1])
> +            self.sockets = self.cores_present/self.threads_per_core
> +            self.cores_per_socket = self.cores_present/self.sockets
> +        else:
> +            # Intel or AMD
> +            self.guest_threads_enabled = True
> +            self.sockets = int(libvirt_topology.get('sockets'))
> +            self.cores_per_socket = int(libvirt_topology.get('cores'))
> +            self.cores_present = self.cores_per_socket * self.sockets
> +            self.cores_available = self.cores_present
> +            self.threads_per_core = int(libvirt_topology.get('threads'))
> +
> +    def lookup(self, ident):
> +        return {
> +            'guest_threads_enabled': self.guest_threads_enabled,
> +            'sockets': self.sockets,
> +            'cores_per_socket': self.cores_per_socket,
> +            'cores_present': self.cores_present,
> +            'cores_available': self.cores_available,
> +            'threads_per_core': self.threads_per_core,
> +            }
> +
> +    def check_topology(self, vcpus, topology):
> +        """
> +            param vcpus: should be an integer
> +            param iso_path: the path of the guest ISO
> +            param topology: {'sockets': x, 'cores': x, 'threads': x}
> +        """
> +        sockets = topology['sockets']
> +        cores = topology['cores']
> +        threads = topology['threads']
> +
> +        if not self.guest_threads_enabled:
> +            raise InvalidOperation("KCHCPUINF0003E")
> +        if vcpus != sockets * cores * threads:
> +            raise InvalidParameter("KCHCPUINF0002E")
> +        if vcpus > self.cores_available * self.threads_per_core:
> +            raise InvalidParameter("KCHCPUINF0001E")
> +        if threads > self.threads_per_core:
> +            raise InvalidParameter("KCHCPUINF0002E")
> diff --git a/src/kimchi/model/templates.py b/src/kimchi/model/templates.py
> index 6e1a571..36dff9f 100644
> --- a/src/kimchi/model/templates.py
> +++ b/src/kimchi/model/templates.py
> @@ -25,6 +25,7 @@
>   from kimchi.exception import InvalidOperation, InvalidParameter
>   from kimchi.exception import NotFoundError, OperationFailed
>   from kimchi.kvmusertests import UserTests
> +from kimchi.model.cpuinfo import CPUInfoModel
>   from kimchi.utils import pool_name_from_uri
>   from kimchi.utils import probe_file_permission_as_user
>   from kimchi.vmtemplate import VMTemplate
> @@ -57,11 +58,12 @@ def create(self, params):
>                   sockets = topology['sockets']
>                   cores = topology['cores']
>                   threads = topology['threads']
> -                vcpus = params.get('cpus')
> -                if vcpus is None:
> +                if params.get('cpus') is None:
>                       params['cpus'] = sockets * cores * threads
> -                elif vcpus != sockets * cores * threads:
> -                    raise InvalidParameter("KCHTMPL0025E")
> +                # check_topoology will raise the appropriate
> +                # exception if a topology is invalid.
> +                CPUInfoModel(conn=self.conn).\
> +                    check_topology(params['cpus'], topology)
>           else:
>               params['cpu_info'] = dict()
>




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