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| author | Jiri Olsa <jolsa@redhat.com> | 2019-06-16 16:13:13 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-07-26 09:12:36 +0200 |
| commit | 826e73e7716d7df01c74ac2a6b792a32da60a6dc (patch) | |
| tree | f8547675a8e4d4220bbda97e3551b29039b4d2aa /arch | |
| parent | 7104a8f31d11690b5f8ae8ec934b7b5afdf96fd0 (diff) | |
| download | linux-stable-826e73e7716d7df01c74ac2a6b792a32da60a6dc.tar.gz linux-stable-826e73e7716d7df01c74ac2a6b792a32da60a6dc.tar.bz2 linux-stable-826e73e7716d7df01c74ac2a6b792a32da60a6dc.zip | |
perf/x86/intel: Disable check_msr for real HW
[ Upstream commit d0e1a507bdc761a14906f03399d933ea639a1756 ]
Tom Vaden reported false failure of the check_msr() function, because
some servers can do POST tracing and enable LBR tracing during
bootup.
Kan confirmed that check_msr patch was to fix a bug report in
guest, so it's ok to disable it for real HW.
Reported-by: Tom Vaden <tom.vaden@hpe.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Tom Vaden <tom.vaden@hpe.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Liang Kan <kan.liang@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190616141313.GD2500@krava
[ Readability edits. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/events/intel/core.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c index 82dad001d1ea..a50e182c38b6 100644 --- a/arch/x86/events/intel/core.c +++ b/arch/x86/events/intel/core.c @@ -19,6 +19,7 @@ #include <asm/intel-family.h> #include <asm/apic.h> #include <asm/cpu_device_id.h> +#include <asm/hypervisor.h> #include "../perf_event.h" @@ -3928,6 +3929,13 @@ static bool check_msr(unsigned long msr, u64 mask) u64 val_old, val_new, val_tmp; /* + * Disable the check for real HW, so we don't + * mess with potentionaly enabled registers: + */ + if (hypervisor_is_type(X86_HYPER_NATIVE)) + return true; + + /* * Read the current value, change it and read it back to see if it * matches, this is needed to detect certain hardware emulators * (qemu/kvm) that don't trap on the MSR access and always return 0s. |