Linus Torvalds writes: (Summary) On Mon, Jan 29, 2018 at 5:32 PM, Arjan van de Ven <arjan@linux.intel.com> wrote:
That sounds reasonable.
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. 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". bit #2 that says "ret falls back on BTB". Then that bit basically becomes the "Skylake bit". Then that bit basically becomes the "Skylake bit".
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in a VM.That sounds reasonable.
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. 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". bit #2 that says "ret falls back on BTB". Then that bit basically becomes the "Skylake bit". Then that bit basically becomes the "Skylake bit".