perf/x86/intel/pt: Don't die on VMXON

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Some versions of Intel PT do not support tracing across VMXON, more
specifically, VMXON will clear TraceEn control bit and any attempt to
set it before VMXOFF will throw a #GP, which in the current state of
things will crash the kernel. Namely:

  $ perf record -e intel_pt// kvm -nographic

on such a machine will kill it.

To avoid this, notify the intel_pt driver before VMXON and after
VMXOFF so that it knows when not to enable itself.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
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: hpa@zytor.com
Link: http://lkml.kernel.org/r/87oa9dwrfk.fsf@ashishki-desk.ger.corp.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

...

This commit is contained in:

Alexander Shishkin 2016-03-29 17:43:10 +03:00 • committed by Ingo Molnar

parent 79c9ce57eb

commit 1c5ac21a0e

4 changed files with 75 additions and 11 deletions

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75

arch/x86/events/intel/pt.c

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3

arch/x86/events/intel/pt.h

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4

arch/x86/include/asm/perf_event.h

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4

arch/x86/kvm/vmx.c

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