Virtualbox has a nice feature called Guest control which through guest additions allows the host to execute commands inside a running guest. This can be useful in many ways such as automating deployment of software in the guest. Is there a way in KVM to execute commands in a running guest from the host system. I'm just interested in Linux hosts and guests.
No, kvm doesn't provide anything like that. But that's not really part of kvm's purpose. Any reason why you can't use ordinary methods for executing commands/deploying software on the guest such as
ssh or even one of the configuration management systems like puppet/chef/whatever?