* David Miller (davem at davemloft.net) wrote: > 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? Yup, it's for the kernel (things like systenter vs int 80 in vdso). thanks, -chris
