Re: [libvirt-users] CPU Resource Reservation using KVM

On Mon, Apr 13, 2015 at 01:41:59PM +0530, Jatin Davey wrote: > On 4/13/2015 1:18 PM, Kashyap Chamarthy wrote: >> On Mon, Apr 13, 2015 at 12:14:12PM +0530, Jatin Davey wrote: >>> Hi All >>> >>> I am new to KVM world. I have been using VMware for about a year. >>> >>> In VMware world we can reserve cpu resources for a VM. Say for instance if >>> we need 4 vCPUs with a total of 8000 GHz then we can mention this >>> configuration in vCenter while creating a VM. This guarantees 8000 GHz of >>> cpu resources for the deployed VM. >>> >>> How can i achieve the same thing using KVM ? >> If you are comfortable with command line, you can look at `virsh` manual >> page for >> >> setvcpus - change number of virtual CPUs >> >> to control how many vCPUs you can allocate. >> >> If you're using `virt-manager`, you should be able to control it via UI >> for a guest under its "Show virtual hardware details" and look for >> "Processor". >> >> > I have looked at virsh and more specifically "setvcpus". You mention that info only now. > We can assign virtual CPUs using it but my question is different. I am > looking at reserving cpu speed to the virtual cpu's. I know we can > allocate and modify the amount vcpu's using setvcpus command but how > can i ask kvm to reserve a particular amount of cpu speed of the host > core's to the virtual cpus. Okay. I don't notice an option to regulate CPU freq. But the closest I see is the 'quota' XML attribute (as part of 'cputune' element) that will "ensure that all vcpus run at the same speed." https://libvirt.org/formatdomain.html#elementsCPUTuning