perf/x86/intel/pt: Fix KVM warning due to doing rdmsr() before the CPUID test
authorHuaitong Han <huaitong.han@intel.com>
Mon, 31 Aug 2015 08:21:02 +0000 (16:21 +0800)
committerIngo Molnar <mingo@kernel.org>
Sun, 13 Sep 2015 09:27:23 +0000 (11:27 +0200)
commit73fdeb66592ee80dffb16fb8a9b7378a00c1a826
tree46543e8b84b8e07f66400b3cca219a110ded8434
parent516792e67c39d31701641ab355acdb9cbfec0643
perf/x86/intel/pt: Fix KVM warning due to doing rdmsr() before the CPUID test

If KVM does not support INTEL_PT, guest MSR_IA32_RTIT_CTL reading will
produce host warning like "kvm [2469]: vcpu0 unhandled rdmsr: 0x570".

Guest can determine whether the CPU supports Intel_PT according to CPUID,
so test_cpu_cap function is added before rdmsr,and it is more in line with
the code style.

Signed-off-by: Huaitong Han <huaitong.han@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: acme@kernel.org
Link: http://lkml.kernel.org/r/1441009262-9792-1-git-send-email-huaitong.han@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
arch/x86/kernel/cpu/perf_event_intel_pt.c