The Power Instruction Set Architecture (ISA) version 2.06 is now available from Power.org. I'm pretty excited about this because it finally includes hardware virtualization support for embedded PowerPC (in contrast to server PowerPC, which has had it for years).
So why does this matter? After all, VirtualLogix, Sysgo, and others have already implemented virtualization layers for embedded PowerPC. The problem is that these solutions require loss of isolation, loss of performance, dramatic modifications to the guest kernels, or some combination of all three.
In KVM for PowerPC (currently supporting PowerPC 440 and e500v2 cores), we chose to maximize isolation and require no changes to the guest kernel; we do this by running the guest kernel in user mode. As a consequence, we suffer reduced performance, since every privileged instruction in the guest kernel traps into the host, and we must emulate it. (Of course, the vast majority of instructions execute natively in hardware.)
Of course, the most important question is when we'll actually see hardware implementing this version of the architecture (and even then, virtualization is an optional feature). IBM hasn't made any announcements about that, but IBM hasn't delivered a new embedded core for a long time now. Freescale has already announced that their e500mc core (as found in their upcoming P4080 processor) will implement virtualization support, and they are even developing their own hypervisor for it.
(Updated Oct 2009 to fix KVM wiki URL.)
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