From: Zachary Amsden <zach at vmware.com> Date: Tue, 18 Jul 2006 04:33:52 -0700 > You really need a CPUID hook. The instruction is non-virtualizable, and > anything claiming to be a hypervisor really has to support masking and > flattening the cpuid namespace for the instruction itself. It is used > in assembler code and very early in boot. The alternative is injecting > a bunch of Xen-specific code to filter feature bits into the i386 layer, > which is both bad for Linux and bad for Xen - and was quite ugly in the > last set of Xen patches. Userspace will still see the full set of cpuid bits, since it can still execute cpuid unimpeded, is this ok?
