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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Stephane Eranian <eranian@google.com>,
        Nelson DSouza <nelson.dsouza@intel.com>,
        "Peter Zijlstra (Intel)" <peterz@infradead.org>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Arnaldo Carvalho de Melo <acme@redhat.com>,
        Jiri Olsa <jolsa@redhat.com>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Vince Weaver <vincent.weaver@maine.edu>, tonyj@suse.com,
        Ingo Molnar <mingo@kernel.org>, Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.0 37/95] perf/x86/intel: Initialize TFA MSR
Date:   Thu,  9 May 2019 20:41:54 +0200
Message-Id: <20190509181311.913201602@linuxfoundation.org>
In-Reply-To: <20190509181309.180685671@linuxfoundation.org>
References: <20190509181309.180685671@linuxfoundation.org>
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[ 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.net
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 77353555d491a..71fb8b7b29545 100644
--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c
@@ -3563,6 +3563,12 @@ 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);
 
-- 
2.20.1