From: Peter Zijlstra peterz@infradead.org
[ Upstream commit d7262457e35dbe239659e62654e56f8ddb814bed ]
Stephane reported that the TFA MSR is not initialized by the kernel, but the TFA bit could set by firmware or as a leftover from a kexec, which makes the state inconsistent.
Reported-by: Stephane Eranian eranian@google.com Tested-by: Nelson DSouza nelson.dsouza@intel.com Signed-off-by: Peter Zijlstra (Intel) peterz@infradead.org Cc: 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: Thomas Gleixner tglx@linutronix.de Cc: Vince Weaver vincent.weaver@maine.edu Cc: tonyj@suse.com Link: https://lkml.kernel.org/r/20190321123849.GN6521@hirez.programming.kicks-ass.... Signed-off-by: Ingo Molnar mingo@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- arch/x86/events/intel/core.c | 6 ++++++ 1 file changed, 6 insertions(+)
diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c index c02a8e6aff52..de0346d651f0 100644 --- a/arch/x86/events/intel/core.c +++ b/arch/x86/events/intel/core.c @@ -3447,6 +3447,12 @@ static void intel_pmu_cpu_starting(int cpu)
cpuc->lbr_sel = NULL;
+ if (x86_pmu.flags & PMU_FL_TFA) { + WARN_ON_ONCE(cpuc->tfa_shadow); + cpuc->tfa_shadow = ~0ULL; + intel_set_tfa(cpuc, false); + } + if (x86_pmu.version > 1) flip_smm_bit(&x86_pmu.attr_freeze_on_smi);