[Kimchi-devel] [PATCH 1/2] Check memory alignment in PowerPC to 256MiB

[Daniel Henrique Barboza]

My suggestion is to put the '256' in a variable/function inside 
osinfo.py for
example and then use it across the code. Hardcoding the alignment in the 
code
will make it harder to change it later, if required.

You can even use this variable as a input in the error message of i18n.py,
making it adaptable.

On 11/10/2015 01:51 PM, Rodrigo Trujillo wrote:
> QEMU for Power requires memory aligned to 256MiB.
> This patch makes the checking and changes if necessary.
>
> Signed-off-by: Rodrigo Trujillo <rodrigo.trujillo at linux.vnet.ibm.com>
> ---
>   src/wok/plugins/kimchi/i18n.py      |  1 +
>   src/wok/plugins/kimchi/model/vms.py | 25 +++++++++++++++++++++++++
>   src/wok/plugins/kimchi/osinfo.py    |  4 ++++
>   3 files changed, 30 insertions(+)
>
> diff --git a/src/wok/plugins/kimchi/i18n.py b/src/wok/plugins/kimchi/i18n.py
> index 42a5e16..9fb4edc 100644
> --- a/src/wok/plugins/kimchi/i18n.py
> +++ b/src/wok/plugins/kimchi/i18n.py
> @@ -115,6 +115,7 @@ messages = {
>       "KCHVM0058E": _("Failed to migrate virtual machine %(name)s due error: %(err)s"),
>       "KCHVM0059E": _("User name of the remote server must be a string."),
>       "KCHVM0060E": _("Destination host of the migration must be a string."),
> +    "KCHVM0061E": _("Memory value %(mem)s must be aligned to 256MiB."),
>   
>       "KCHVMHDEV0001E": _("VM %(vmid)s does not contain directly assigned host device %(dev_name)s."),
>       "KCHVMHDEV0002E": _("The host device %(dev_name)s is not allowed to directly assign to VM."),
> diff --git a/src/wok/plugins/kimchi/model/vms.py b/src/wok/plugins/kimchi/model/vms.py
> index 0641ae8..3965906 100644
> --- a/src/wok/plugins/kimchi/model/vms.py
> +++ b/src/wok/plugins/kimchi/model/vms.py
> @@ -21,6 +21,7 @@ import copy
>   import libvirt
>   import lxml.etree as ET
>   import os
> +import platform
>   import random
>   import socket
>   import string
> @@ -232,6 +233,13 @@ class VMModel(object):
>               vm_locks[name] = lock
>   
>           with lock:
> +            # make sure memory is alingned in 256MiB
> +            distro, _, _ = platform.linux_distribution()
> +            if 'memory' in params and distro == "IBM_PowerKVM":
> +                if params['memory'] % 256 != 0:
> +                    raise InvalidParameter('KCHVM0061E',
> +                                           {'mem': str(params['memory'])})
> +
>               dom = self.get_vm(name, self.conn)
>               vm_name, dom = self._static_vm_update(name, dom, params)
>               self._live_vm_update(dom, params)
> @@ -800,6 +808,17 @@ class VMModel(object):
>                   raise OperationFailed("KCHVM0041E")
>               elif slots == 0:
>                   slots = 1
> +
> +            force_max_mem_update = False
> +            distro, _, _ = platform.linux_distribution()
> +            if distro == "IBM_PowerKVM":
> +                # max memory 256MiB alignment
> +                host_mem -= (host_mem % 256)
> +                # force max memory update if it exists but it's wrong.
> +                if maxMem is not None and\
> +                   int(maxMem.text) != (host_mem * 1024):
> +                    force_max_mem_update = True
> +
>               if maxMem is None:
>                   max_mem_xml = E.maxMemory(
>                       str(host_mem * 1024),
> @@ -813,6 +832,12 @@ class VMModel(object):
>                                             './maxMemory',
>                                             str(slots),
>                                             attr='slots')
> +
> +                if force_max_mem_update:
> +                    new_xml = xml_item_update(new_xml,
> +                                              './maxMemory',
> +                                              str(host_mem * 1024))
> +
>               return new_xml
>           return ET.tostring(root, encoding="utf-8")
>   
> diff --git a/src/wok/plugins/kimchi/osinfo.py b/src/wok/plugins/kimchi/osinfo.py
> index 75a21ff..c915e6d 100644
> --- a/src/wok/plugins/kimchi/osinfo.py
> +++ b/src/wok/plugins/kimchi/osinfo.py
> @@ -204,6 +204,10 @@ def lookup(distro, version):
>       # set up arch to ppc64 instead of ppc64le due to libvirt compatibility
>       if params["arch"] == "ppc64le":
>           params["arch"] = "ppc64"
> +        # in Power, memory must be aligned in 256MiB
> +        if (params['max_memory'] / 1024) % 256 != 0:
> +            alignment = params['max_memory'] % (256 * 1024)
> +            params['max_memory'] -= alignment
>   
>       if distro in modern_version_bases[arch]:
>           if LooseVersion(version) >= LooseVersion(