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We can merge these syntax to specify some CPU and ranges of CPUs.

VM configuration

The official documentation on the XML format of libvirt is here.

Resources

On the XML configuration of a virtual machine, the resource can be specified to know which slice should be used (more details here). So, the virtual machine will only have acces to the CPU associated with the slice.

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In the project, this element will be used to limite the virtual machine.

• The emulatorpin element specifies which of host physical CPUs the emulator, a subset of a domain not including vCPU or iothreads will be pinned to.
• The vcpupin element specify specifies which of host's physical CPUs the domain vCPU will be pinned to (more details here). It's used to reserved one or more CPUs for a critical virtual machine. So, it's important not use this CPU on another VM.
• The vcpusched element specify specifies the scheduler type for a particular vCPU.