On Fri, May 17, 2013 at 11:16:51AM +0200, Borislav Petkov wrote: > On Fri, May 17, 2013 at 11:04:51AM +0200, Peter Zijlstra wrote: > > Mostly so that check_hw_exists() doesn't need to know about the vendor > > specifics like where the MSRs live, how many there are etc.. > > Yep, but there will still be issues with perf when booted on a guest and > kvm not supporting it. And AFAIU, they're signalling this by turning off > CPUID bits so that initializing perf doesn't happen. > > So, I think init_hw_perf_events should as a first step look at CPUID > bits and then do anything else. And this is done on Intel with > X86_FEATURE_ARCH_PERFMON. But Robert is fixing this on AMD too so...
But not all x86 hardware even has the stuff enumerated in CPUID, and afaict Intel and AMD use a different CPUID bit as well, so what's init_hw_perf_events() to do? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
