Commit-ID: d0e1a507bdc761a14906f03399d933ea639a1756 Gitweb: https://git.kernel.org/tip/d0e1a507bdc761a14906f03399d933ea639a1756 Author: Jiri Olsa <jo...@redhat.com> AuthorDate: Sun, 16 Jun 2019 16:13:13 +0200 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Mon, 17 Jun 2019 12:36:24 +0200
perf/x86/intel: Disable check_msr for real HW 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.va...@hpe.com> Signed-off-by: Jiri Olsa <jo...@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org> Acked-by: Tom Vaden <tom.va...@hpe.com> Cc: Alexander Shishkin <alexander.shish...@linux.intel.com> Cc: Arnaldo Carvalho de Melo <a...@kernel.org> Cc: Liang Kan <kan.li...@linux.intel.com> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Namhyung Kim <namhy...@kernel.org> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Thomas Gleixner <t...@linutronix.de> Link: https://lkml.kernel.org/r/20190616141313.GD2500@krava [ Readability edits. ] Signed-off-by: Ingo Molnar <mi...@kernel.org> --- arch/x86/events/intel/core.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c index 5e6ae481dee7..bda450ff51ee 100644 --- a/arch/x86/events/intel/core.c +++ b/arch/x86/events/intel/core.c @@ -20,6 +20,7 @@ #include <asm/intel-family.h> #include <asm/apic.h> #include <asm/cpu_device_id.h> +#include <asm/hypervisor.h> #include "../perf_event.h" @@ -4050,6 +4051,13 @@ 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
