cloudstack-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Wei Zhou" <w.z...@leaseweb.com>
Subject Re: Review Request 12360: custom cpu model for kvm guest.the default model 'QEMU Virtual CPU version xxx' affect the activation of Windows OS and low performance.
Date Wed, 10 Jul 2013 06:50:43 GMT

-----------------------------------------------------------
This is an automatically generated e-mail. To reply, visit:
https://reviews.apache.org/r/12360/#review22949
-----------------------------------------------------------



plugins/hypervisors/kvm/src/com/cloud/hypervisor/kvm/resource/LibvirtVMDef.java
<https://reviews.apache.org/r/12360/#comment46734>

    It is mentioned in http://libvirt.org/formatdomain.html that "Since 0.9.10, an optional
mode attribute may be used to make it easier to configure a guest CPU to be as close to host
CPU as possible". Hence, I think it is better to compare _libvirtVersion here. This feature
supports from libvirt 0.9.10.


- Wei Zhou


On July 10, 2013, 3 a.m., Jijun Liu wrote:
> 
> -----------------------------------------------------------
> This is an automatically generated e-mail. To reply, visit:
> https://reviews.apache.org/r/12360/
> -----------------------------------------------------------
> 
> (Updated July 10, 2013, 3 a.m.)
> 
> 
> Review request for cloudstack, edison su, soren, and Wei Zhou.
> 
> 
> Repository: cloudstack-git
> 
> 
> Description
> -------
> 
> Add cpu model for kvm guest.Now all the kvm guest's cpu model is 'QEMU Virtual CPU version
xxx'. This will affect the activation of Windows OS and low performance. I add three mode
for user to indicate the guest cpu model. some ideas come from openstack and libvirt.
> user can uncomment guest.cpu.mode and guest.cpu.model in agent.properties to enable this
feature.it is disabled by default.
> some details as follows:
> custom - user custom the CPU model which specified by guest.cpu.model.
> host-model - identify the named CPU model which most closely matches the host, and then
request additional CPU flags to complete the match. This should give close to maximum functionality/performance,
which maintaining good reliability/compatibility if the guest is migrated to another host
with slightly different host CPUs.
> host-passthrough - tell KVM to passthrough the host CPU with no modifications. The difference
to host-model, instead of just matching feature flags, every last detail of the host CPU is
matched. This gives absolutely best performance,and can be important to some apps which check
low level CPU details, but it comes at a cost wrt migration. The guest can only be migrated
to an exactly matching host CPU. 
> 
> 
> Diffs
> -----
> 
>   agent/conf/agent.properties 60030ae 
>   plugins/hypervisors/kvm/src/com/cloud/hypervisor/kvm/resource/LibvirtComputingResource.java
914017c 
>   plugins/hypervisors/kvm/src/com/cloud/hypervisor/kvm/resource/LibvirtVMDef.java 5120870

>   plugins/hypervisors/kvm/test/com/cloud/hypervisor/kvm/resource/LibvirtVMDefTest.java
2c0ff8d 
> 
> Diff: https://reviews.apache.org/r/12360/diff/
> 
> 
> Testing
> -------
> 
> 1.set guest.cpu.mode=custom,guest.cpu.model=Nehalem in agent.properties,you can get more
guest.cpu.model by execute virsh capabilities .create a new vm instance or reboot your vm
instance,the guest's cpu model will change as guest.cpu.model specified.
> 2.set guest.cpu.mode=host-model,create a new vm instance or reboot your vm instance the
guest's cpu model will be a closely cpu model as your hypervisor.
> 3.set guest.cpu.mode=host-passthrough,create a new vm instance or reboot your vm instance,the
guest's cpu model should be the cpu model as your hypervisor.
> 
> 
> Thanks,
> 
> Jijun Liu
> 
>


Mime
  • Unnamed multipart/alternative (inline, None, 0 bytes)
View raw message