lkml.org 
[lkml]   [2019]   [Apr]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[tip:perf/urgent] perf/x86/intel: Initialize TFA MSR
Commit-ID:  d7262457e35dbe239659e62654e56f8ddb814bed
Gitweb: https://git.kernel.org/tip/d7262457e35dbe239659e62654e56f8ddb814bed
Author: Peter Zijlstra <peterz@infradead.org>
AuthorDate: Thu, 21 Mar 2019 13:38:49 +0100
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Wed, 3 Apr 2019 11:40:32 +0200

perf/x86/intel: Initialize TFA MSR

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>
---
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 1539647ea39d..f61dcbef20ff 100644
--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c
@@ -3575,6 +3575,12 @@ 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);

\
 
 \ /
  Last update: 2019-04-03 12:41    [W:0.090 / U:6.268 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site