The past several years have brought many additions to the x86 architecture that makes it more than shit atop shit. When he wrote it, things like Xen required you to build a kernel with special options for it to run, with all kinds of new and exciting bugs to discover. Things like page table virtualization, which provide a lot better page protection, or being able to shadow the vm control structures, which allow for nested VMs, or IOMMUs, which allow vms to access explicit pieces of hardware, just didn't exist. x86 is in a better condition for virtualization now, and layouts can finally done in a semi-sane way.
Yeah, but on the other hand one might argue that there is no reason to believe Intel's hardware implementation of such features is more correct and less prone to errors than Xen's implementation in software.
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The past several years have brought many additions to the x86 architecture that makes it more than shit atop shit. When he wrote it, things like Xen required you to build a kernel with special options for it to run, with all kinds of new and exciting bugs to discover. Things like page table virtualization, which provide a lot better page protection, or being able to shadow the vm control structures, which allow for nested VMs, or IOMMUs, which allow vms to access explicit pieces of hardware, just didn't exist. x86 is in a better condition for virtualization now, and layouts can finally done in a semi-sane way.
Yeah, but on the other hand one might argue that there is no reason to believe Intel's hardware implementation of such features is more correct and less prone to errors than Xen's implementation in software.