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Date: Tue, 30 Mar 2010 17:00:55 +0200
From: Peter Zijlstra <peterz@...radead.org>
To: Stephane Eranian <eranian@...gle.com>
Cc: Robert Richter <robert.richter@....com>,
Ingo Molnar <mingo@...e.hu>,
LKML <linux-kernel@...r.kernel.org>,
Cyrill Gorcunov <gorcunov@...il.com>
Subject: Re: [PATCH 0/3] perf/core, x86: unify perfctr bitmasks
On Tue, 2010-03-30 at 15:53 +0200, Stephane Eranian wrote:
> > So, there are some ARCH_PERFMON_EVENTSEL_* masks that are Intel only,
> > which is true for ARCH_PERFMON_EVENTSEL_ANY. And indead, the code
> > should be checked for this. ARCH_PERFMON_EVENTSEL_ANY is always
> > cleared on AMD cpus, so this code is ok. Actually the bit is cleared
>
> Until AMD uses that bit too and you won't notice this test. This is a security
> check specific to Intel and it should be in an Intel-specific function.
>
> > for *all* cpus in x86_pmu_raw_event(), the code was and is broken for
> > this.
> >
> Yes, needs to be authorized for any perfmon v3 and later revisions.
So how about something like this on top of Robert's patches?
---
arch/x86/kernel/cpu/perf_event.c | 16 ++++++----------
arch/x86/kernel/cpu/perf_event_amd.c | 5 +++--
arch/x86/kernel/cpu/perf_event_intel.c | 15 ++++++++++++++-
arch/x86/kernel/cpu/perf_event_p4.c | 5 +++--
4 files changed, 26 insertions(+), 15 deletions(-)
Index: linux-2.6/arch/x86/kernel/cpu/perf_event.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/cpu/perf_event.c
+++ linux-2.6/arch/x86/kernel/cpu/perf_event.c
@@ -201,7 +201,7 @@ struct x86_pmu {
unsigned eventsel;
unsigned perfctr;
u64 (*event_map)(int);
- u64 (*raw_event)(u64);
+ int (*raw_event)(struct perf_event *event);
int max_events;
int num_counters;
int num_counters_fixed;
@@ -445,9 +445,10 @@ static int x86_hw_config(struct perf_eve
return 0;
}
-static u64 x86_pmu_raw_event(u64 hw_event)
+static int x86_pmu_raw_event(struct perf_event *event)
{
- return hw_event & X86_RAW_EVENT_MASK;
+ event->hw.config |= event->attr.config & X86_RAW_EVENT_MASK;
+ return 0;
}
/*
@@ -511,13 +512,8 @@ static int __hw_perf_event_init(struct p
/*
* Raw hw_event type provide the config in the hw_event structure
*/
- if (attr->type == PERF_TYPE_RAW) {
- hwc->config |= x86_pmu.raw_event(attr->config);
- if ((hwc->config & ARCH_PERFMON_EVENTSEL_ANY) &&
- perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN))
- return -EACCES;
- return 0;
- }
+ if (attr->type == PERF_TYPE_RAW)
+ return x86_pmu.raw_event(event);
if (attr->type == PERF_TYPE_HW_CACHE)
return set_ext_hw_attr(hwc, attr);
Index: linux-2.6/arch/x86/kernel/cpu/perf_event_amd.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/cpu/perf_event_amd.c
+++ linux-2.6/arch/x86/kernel/cpu/perf_event_amd.c
@@ -111,9 +111,10 @@ static u64 amd_pmu_event_map(int hw_even
return amd_perfmon_event_map[hw_event];
}
-static u64 amd_pmu_raw_event(u64 hw_event)
+static int amd_pmu_raw_event(struct perf_event *event)
{
- return hw_event & AMD64_RAW_EVENT_MASK;
+ event->hw.config |= event->attr.config & AMD64_RAW_EVENT_MASK;
+ return 0;
}
/*
Index: linux-2.6/arch/x86/kernel/cpu/perf_event_intel.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/cpu/perf_event_intel.c
+++ linux-2.6/arch/x86/kernel/cpu/perf_event_intel.c
@@ -758,6 +758,19 @@ intel_get_event_constraints(struct cpu_h
return x86_get_event_constraints(cpuc, event);
}
+static int intel_pmu_raw_event(struct perf_event *event)
+{
+ int ret = x86_pmu_raw_event(event);
+ if (ret)
+ return ret;
+
+ if ((event->hw.config & ARCH_PERFMON_EVENTSEL_ANY) &&
+ perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN))
+ return -EACCES;
+
+ return 0;
+}
+
static __initconst struct x86_pmu core_pmu = {
.name = "core",
.handle_irq = x86_pmu_handle_irq,
@@ -809,7 +822,7 @@ static __initconst struct x86_pmu intel_
.eventsel = MSR_ARCH_PERFMON_EVENTSEL0,
.perfctr = MSR_ARCH_PERFMON_PERFCTR0,
.event_map = intel_pmu_event_map,
- .raw_event = x86_pmu_raw_event,
+ .raw_event = intel_pmu_raw_event,
.max_events = ARRAY_SIZE(intel_perfmon_event_map),
.apic = 1,
/*
Index: linux-2.6/arch/x86/kernel/cpu/perf_event_p4.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/cpu/perf_event_p4.c
+++ linux-2.6/arch/x86/kernel/cpu/perf_event_p4.c
@@ -425,11 +425,12 @@ static u64 p4_pmu_event_map(int hw_event
* on HT machine but allow HT-compatible specifics to be
* passed on)
*/
-static u64 p4_pmu_raw_event(u64 hw_event)
+static int p4_pmu_raw_event(struct perf_event *event)
{
- return hw_event &
+ event->hw.config |= event->attr.config &
(p4_config_pack_escr(P4_ESCR_MASK_HT) |
p4_config_pack_cccr(P4_CCCR_MASK_HT));
+ return 0;
}
static int p4_hw_config(struct perf_event_attr *attr, struct hw_perf_event *hwc)
--
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