/me reminds you of 78 char text wrap.
On Wed, Jul 09, 2014 at 07:32:09PM +, Liang, Kan wrote:
Sure; but what I meant was, check_msr() is broken when ran on such a
kernel. You need to fix check_msr() to return failure on these 'ignored'
MSRs, after all they don't function as expected,
On Tue, Jul 08, 2014 at 09:49:40AM -0700, kan.li...@intel.com wrote:
diff --git a/arch/x86/kernel/cpu/perf_event.c
b/arch/x86/kernel/cpu/perf_event.c
index 2bdfbff..f0e8022 100644
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -118,6 +118,9 @@ static int
On Tue, Jul 08, 2014 at 09:49:40AM -0700, kan.li...@intel.com wrote:
diff --git a/arch/x86/kernel/cpu/perf_event.c
b/arch/x86/kernel/cpu/perf_event.c
index 2bdfbff..f0e8022 100644
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -118,6 +118,9 @@ static int
On Tue, Jul 08, 2014 at 09:49:40AM -0700, kan.li...@intel.com wrote:
+ /*
+ * Access LBR MSR may cause #GP under certain circumstances.
+ * E.g. KVM doesn't support LBR MSR
+ * Check all LBT MSR here.
+ * Disable LBR access if any LBR MSRs can not be accessed.
+
On Tue, Jul 08, 2014 at 09:49:40AM -0700, kan.li...@intel.com wrote:
--- a/arch/x86/kernel/cpu/perf_event.h
+++ b/arch/x86/kernel/cpu/perf_event.h
@@ -464,6 +464,12 @@ struct x86_pmu {
*/
struct extra_reg *extra_regs;
unsigned int er_flags;
+ /*
+ * EXTRA REG
On Tue, Jul 08, 2014 at 09:49:40AM -0700, kan.li...@intel.com wrote:
--- a/arch/x86/kernel/cpu/perf_event.h
+++ b/arch/x86/kernel/cpu/perf_event.h
@@ -464,6 +464,12 @@ struct x86_pmu {
*/
struct extra_reg *extra_regs;
unsigned int er_flags;
+ /*
+* EXTRA REG
On Tue, Jul 08, 2014 at 09:49:40AM -0700, kan.li...@intel.com wrote:
+/*
+ * Under certain circumstances, access certain MSR may cause #GP.
+ * The function tests if the input MSR can be safely accessed.
+ */
+static inline bool check_msr(unsigned long msr)
+{
+ u64 value;
+
+ if
On Tue, Jul 08, 2014 at 09:49:40AM -0700, kan.li...@intel.com wrote:
+/*
+ * Under certain circumstances, access certain MSR may cause #GP.
+ * The function tests if the input MSR can be safely accessed.
+ */
+static inline bool check_msr(unsigned long msr) {
+ u64 value;
+
+
On Wed, Jul 09, 2014 at 02:32:28PM +, Liang, Kan wrote:
On Tue, Jul 08, 2014 at 09:49:40AM -0700, kan.li...@intel.com wrote:
+/*
+ * Under certain circumstances, access certain MSR may cause #GP.
+ * The function tests if the input MSR can be safely accessed.
+ */
+static
-Original Message-
From: Peter Zijlstra [mailto:pet...@infradead.org]
Sent: Wednesday, July 09, 2014 10:58 AM
To: Liang, Kan
Cc: a...@firstfloor.org; linux-ker...@vger.kernel.org; kvm@vger.kernel.org
Subject: Re: [PATCH V4 1/2] perf ignore LBR and extra_regs.
On Wed, Jul 09
: [PATCH V4 1/2] perf ignore LBR and extra_regs.
On Wed, Jul 09, 2014 at 02:32:28PM +, Liang, Kan wrote:
On Tue, Jul 08, 2014 at 09:49:40AM -0700, kan.li...@intel.com wrote:
+/*
+ * Under certain circumstances, access certain MSR may cause #GP.
+ * The function tests
On Wed, Jul 09, 2014 at 02:32:28PM +, Liang, Kan wrote:
On Tue, Jul 08, 2014 at 09:49:40AM -0700, kan.li...@intel.com wrote:
+/*
+ * Under certain circumstances, access certain MSR may cause #GP.
+ * The function tests if the input MSR can be safely
From: Kan Liang kan.li...@intel.com
x86, perf: Protect LBR and extra_regs against KVM lying
With -cpu host, KVM reports LBR and extra_regs support, if the host has support.
When the guest perf driver tries to access LBR or extra_regs MSR,
it #GPs all MSR accesses,since KVM doesn't handle LBR and
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