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Red Hat & AMD Demo Live VM Migration Across CPU Vendors
An anonymous reader notes an Inquirer story reporting on something of a breakthrough in virtual machine management — a demonstration (not yet a product) of migrating a running virtual machine across CPUs from different vendors (video here). "Red Hat and AMD have just done the so called impossible, and demonstrated VM live migration across CPU architectures. Not only that, they have demonstrated it across CPU vendors, potentially commoditizing server processors. This is quite a feat. Only a few months ago during VMworld, Intel and VMware claimed that this was impossible. Judging by an initial response, VMware is quite irked by this KVM accomplishment and they are pointing to stability concerns. This sound like scaremongering to me ... All the interesting controversy aside, cross-vendor migration is [obviously] a good thing for customers because it avoids platform lock-in."
This is completely trivial. You simply have to mark the VM with the architecture of its code. Then each host contains both a virtualization layer (à la vmware) and a multi-platform emulator (à la qemu). If the VM matches the architecture the host is running on, you use the virtualization layer, if it doesn't, you use the emulator.
As for moving between AMD64 and Intel 64 (for example), the VM has to emulate the few instructions that differ and virtualize the rest.
Of course, cross-architecture migration is not that useful since you have an emulation penalty. It is much simpler (and cheaper) to do everything on x64.