The equivalent to flushing your register state is more comparable to a context switch than a complete shut down. Also Thanks to PCIe CPU swapping could be done in pure software at the OS level. No further hardware changes required. Simply copy the contents of your RAM to the other CPU card and manage the hand-off. This is clearly different from a complete shutdown e.g. all devices on the PCIe bus would be able to keep their state.
A good programmer familiar with the target OS and inner workings of PCIe could deliver a working prototype within a week, production ready within less than a year.
As a web developer unfamiliar with the hardware stack, I was surprised by this part...
> A good programmer familiar with the target OS and inner workings of PCIe could deliver a working prototype within a week, production ready within less than a year.
Could you please explain why it'd be normal to take a year to go from prototype to production in this case? What would happen in that one year, starting from a working prototype?
Most of the time will be spend on undocumented corner cases of third party hardware and dealing with various race conditions. Even though the PCIe protocol is reasonably simple the devices attached to it are not. Since this feature is only viable if it works 100% reliable the rule of thumb is the last 20% of problems will cost you 80% of the time.
A good programmer familiar with the target OS and inner workings of PCIe could deliver a working prototype within a week, production ready within less than a year.