Messages in this thread | | | From | Linus Torvalds <> | Date | Mon, 29 Jan 2018 19:32:06 -0800 | Subject | Re: [RFC,05/10] x86/speculation: Add basic IBRS support infrastructure |
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On Mon, Jan 29, 2018 at 5:32 PM, Arjan van de Ven <arjan@linux.intel.com> wrote: > > the most simple solution is that we set the internal feature bit in Linux > to turn on the "stuff the RSB" workaround is we're on a SKL *or* as a guest > in a VM.
That sounds reasonable.
However, wouldn't it be even better to extend on the current cpuid model, and actually have some real architectural bits in there.
Maybe it could be a bit in that IA32_ARCH_CAPABILITIES MSR. Say, add a bit #2 that says "ret falls back on BTB".
Then that bit basically becomes the "Skylake bit". Hmm?
Linus
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