Starting with VMware Workstation 6.0, VMware is introducing new capabilities in its virtual infrastructures. One of them allows virtual machines to exchange data without using guest OSes network-based approaches like FTP, NFS, NetBIOS, etc.
This capability is granted by a new experimental interface called VMCI:
The Virtual Machine Communication Interface (VMCI) supports fast and efficient communication between a virtual machine and the host operating system and between two or more virtual machines on the same host.
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Without VMCI, virtual machines communicate with the host using the network layer. Using the network layer adds overhead to the communication. With VMCI communication overhead is minimal and different tasks that require that communication can be optimized…
This interface allows transmission of small messages between VMs, as well as sharing of complex data like guest OSes memory.
This opens new possibilities in solving old problems like high availability: think about a virtual cluster where nodes are no more required to communicate by network to share data and activate fail-over.
At the same time, capability to share with host OS, makes VMCI suitable for solving new class of problems, like efficient security check of virtual machines: think about a virtual infrastructure where anti-virus, host intrusion detection systems, endpoint security agents, etc., are controlling guest OSes integrity from host level, without the need to install same agent software inside all virtual machines.
Considering such opportunities, once this technology will be available on VMware server-class products it may allow new generation of security tools.
Read the whole VMCI documentation at source.
This is possibly what Steve Herrod, Vice President of Technology Development at VMware, was referring to in his keynote at Symposia 2007.