[tip:perf/urgent] perf/x86: Disable uncore on virtualized CPUs

[tip-bot for Yan, Zheng]

Commit-ID:  a05123bdd1b9ba961ed262864924a5b3ee81afe8
Gitweb:     http://git.kernel.org/tip/a05123bdd1b9ba961ed262864924a5b3ee81afe8
Author:     Yan, Zheng <zheng.z.yan@xxxxxxxxx>
AuthorDate: Tue, 21 Aug 2012 17:08:37 +0800
Committer:  Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Sat, 20 Oct 2012 10:07:02 +0200

perf/x86: Disable uncore on virtualized CPUs

Initializing uncore PMU on virtualized CPU may hang the kernel.
This is because kvm does not emulate the entire hardware. Thers
are lots of uncore related MSRs, making kvm enumerate them all
is a non-trival task. So just disable uncore on virtualized CPU.

Signed-off-by: Yan, Zheng <zheng.z.yan@xxxxxxxxx>
Tested-by: Pekka Enberg <penberg@xxxxxxxxxx>
Cc: a.p.zijlstra@xxxxxxxxx
Cc: eranian@xxxxxxxxxx
Cc: andi@xxxxxxxxxxxxxx
Cc: avi@xxxxxxxxxx
Link: http://lkml.kernel.org/r/1345540117-14164-1-git-send-email-zheng.z.yan@xxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
 arch/x86/kernel/cpu/perf_event_intel_uncore.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/arch/x86/kernel/cpu/perf_event_intel_uncore.c b/arch/x86/kernel/cpu/perf_event_intel_uncore.c
index 99d96a4..5df8d32 100644
--- a/arch/x86/kernel/cpu/perf_event_intel_uncore.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_uncore.c
@@ -2926,6 +2926,9 @@ static int __init intel_uncore_init(void)
 	if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL)
 		return -ENODEV;
 
+	if (cpu_has_hypervisor)
+		return -ENODEV;
+
 	ret = uncore_pci_init();
 	if (ret)
 		goto fail;
--
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