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Subject[PATCH AUTOSEL 5.2 73/76] perf/x86: Apply more accurate check on hypervisor platform
Date
From: Zhenzhong Duan <zhenzhong.duan@oracle.com>

[ Upstream commit 5ea3f6fb37b79da33ac9211df336fd2b9f47c39f ]

check_msr is used to fix a bug report in guest where KVM doesn't support
LBR MSR and cause #GP.

The msr check is bypassed on real HW to workaround a false failure,
see commit d0e1a507bdc7 ("perf/x86/intel: Disable check_msr for real HW")

When running a guest with CONFIG_HYPERVISOR_GUEST not set or "nopv"
enabled, current check isn't enough and #GP could trigger.

Signed-off-by: Zhenzhong Duan <zhenzhong.duan@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Juergen Gross <jgross@suse.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/1564022366-18293-1-git-send-email-zhenzhong.duan@oracle.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/x86/events/intel/core.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
index e9042e3f3052c..6179be624f357 100644
--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c
@@ -20,7 +20,6 @@
#include <asm/intel-family.h>
#include <asm/apic.h>
#include <asm/cpu_device_id.h>
-#include <asm/hypervisor.h>

#include "../perf_event.h"

@@ -4057,7 +4056,7 @@ static bool check_msr(unsigned long msr, u64 mask)
* Disable the check for real HW, so we don't
* mess with potentionaly enabled registers:
*/
- if (hypervisor_is_type(X86_HYPER_NATIVE))
+ if (!boot_cpu_has(X86_FEATURE_HYPERVISOR))
return true;

/*
--
2.20.1
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