Why does Red Hat and Fedora software not distinguish between AMD and Intel kernels?

[Neil Horman]

On Fri, Feb 07, 2014 at 03:01:15PM +0000, James Harrison wrote:
> Hi.
> Thanks for the quick reply.
> 
> So what architecture does Red Hat compile its kernels for? Having compiled the Linux Kernel, you must specify target architecture. Is there now a "general cpu" option?
> 
Yes, again, look at arch/x86/Kconfig[.cpu].  There is a generic option for
x86_64 arches.

> For specific CPU features like virtualisation flags, how do kernels know to report the correct CPU features? Is there a Red Hat patch?
> 
What?  You have this backwards.  the kernel doesn't assert virtualization flags
(or other feature flags) on a cpu, the kernel retrieves them from the cpu, and
make code path decisions based on that information.  Specifically the kernel
uses the cpuid instruction to fetch cpu flags so the kernel knows what features
it can support.

Neil