JPC: x86 Java Emulator

The authors of this chapter present an interesting technique, using emulation rather than VMs in order to allow for an increase in code portability. My concern is that the gain in portability does not outweigh the negatives of this approach. Since you're emulating the system itself it is unnecessary to run the system on customized hardware, removing a lot of the negatives we discussed in the chapter on Xen, such as having to customize the OS, or write special processing stacks to handle the computations as needed. Unfortunately, since you're running a simulation, it is necessary to expend processing power to run the simulation, then additional power to actually run the contents. This performance hit is severe, and it makes the idea of general purpose environmental emulation questionable, since, as was mentioned in the Xen chapter, hardware companies are making it easier to run VMs instead.

One place the idea of emulation may take hold is not necessarily the emulation of x86, but full emulations of more complex hardware packages, like smartphones. This would allow for quick deployment testing of software on multiple platforms and I'm sure this is already a standard use of emulation. Emulating the x86 hardware space seems less interesting beyond the reasons listed above because there is a lot of platform development making laptops lighter, faster, and longer lasting. If you can bring the entire physical system with you without a performance cost then other approaches that provide the same portability but have performance hits will be of less interest to users.

The only thing that this emulation has going for it is that since everything is being run inside a safely contained box there is minimal risk to security. As the article points out you're going to need three failures: the program in use, the emulator, and then the OS itself in order to actually cause damage to the system underneath the emulator. And having all three of these failures correctly interact to allow the transmission of damaging or malicious code is going to be difficult to orchestrate.

Also, why are the Tips not in order? Did that bother anyone else?