Re: [PATCH V6 2/5] perf/x86/kvm: Avoid unnecessary work in guest filtering

From: Peter Zijlstra
Date: Mon Feb 04 2019 - 10:44:22 EST


On Mon, Feb 04, 2019 at 04:38:27PM +0100, Peter Zijlstra wrote:
> +static const struct x86_cpu_desc isolation_ucodes[] = {
> + INTEL_CPU_DESC(INTEL_FAM6_KABYLAKE_MOBILE, 9, 0x0000004e),
> + INTEL_CPU_DESC(INTEL_FAM6_KABYLAKE_MOBILE, 10, 0x0000004e),
> + INTEL_CPU_DESC(INTEL_FAM6_KABYLAKE_MOBILE, 11, 0x0000004e),
> + INTEL_CPU_DESC(INTEL_FAM6_KABYLAKE_MOBILE, 12, 0x0000004e),

> + INTEL_CPU_DESC(INTEL_FAM6_KABYLAKE_DESKTOP, 10, 0x0000004e),
> + INTEL_CPU_DESC(INTEL_FAM6_KABYLAKE_DESKTOP, 11, 0x0000004e),
> + INTEL_CPU_DESC(INTEL_FAM6_KABYLAKE_DESKTOP, 12, 0x0000004e),
> + INTEL_CPU_DESC(INTEL_FAM6_KABYLAKE_DESKTOP, 13, 0x0000004e),

Do we want a special stepping (0 / -1) to be able to denote 'all' ?