diff mbox series

[v2,5/7] perf/x86/amd/ibs: Fix raw sample data accumulation

Message ID 20200908214740.18097-6-kim.phillips@amd.com
State New
Headers show
Series [tip:,perf/core] perf/x86/amd/ibs: Fix raw sample data accumulation | expand

Commit Message

Kim Phillips Sept. 8, 2020, 9:47 p.m. UTC 
Neither IbsBrTarget nor OPDATA4 are populated in IBS Fetch mode.
Don't accumulate them into raw sample user data in that case.

Also, in Fetch mode, add saving the IBS Fetch Control Extended MSR.

Technically, there is an ABI change here with respect to the IBS raw
sample data format, but I don't see any perf driver version information
being included in perf.data file headers, but, existing users can detect
whether the size of the sample record has reduced by 8 bytes to
determine whether the IBS driver has this fix.

Reported-by: Stephane Eranian <stephane.eranian@google.com>
Signed-off-by: Kim Phillips <kim.phillips@amd.com>
Fixes: 904cb3677f3a ("perf/x86/amd/ibs: Update IBS MSRs and feature definitions")
Cc: Stephane Eranian <eranian@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: LKML <linux-kernel@vger.kernel.org>
Cc: x86 <x86@kernel.org>
Cc: stable@vger.kernel.org
---
v2: no changes.

 arch/x86/events/amd/ibs.c        | 26 ++++++++++++++++----------
 arch/x86/include/asm/msr-index.h |  1 +
 2 files changed, 17 insertions(+), 10 deletions(-)
diff mbox series

Patch

diff --git a/arch/x86/events/amd/ibs.c b/arch/x86/events/amd/ibs.c
index 68776cc291a6..ace28be4cbda 100644
--- a/arch/x86/events/amd/ibs.c
+++ b/arch/x86/events/amd/ibs.c
@@ -637,18 +637,24 @@  static int perf_ibs_handle_irq(struct perf_ibs *perf_ibs, struct pt_regs *iregs)
 				       perf_ibs->offset_max,
 				       offset + 1);
 	} while (offset < offset_max);
+	/*
+	 * Read IbsBrTarget, IbsOpData4, and IbsExtdCtl separately
+	 * depending on their availability.
+	 * Can't add to offset_max as they are staggered
+	 */
 	if (event->attr.sample_type & PERF_SAMPLE_RAW) {
-		/*
-		 * Read IbsBrTarget and IbsOpData4 separately
-		 * depending on their availability.
-		 * Can't add to offset_max as they are staggered
-		 */
-		if (ibs_caps & IBS_CAPS_BRNTRGT) {
-			rdmsrl(MSR_AMD64_IBSBRTARGET, *buf++);
-			size++;
+		if (perf_ibs == &perf_ibs_op) {
+			if (ibs_caps & IBS_CAPS_BRNTRGT) {
+				rdmsrl(MSR_AMD64_IBSBRTARGET, *buf++);
+				size++;
+			}
+			if (ibs_caps & IBS_CAPS_OPDATA4) {
+				rdmsrl(MSR_AMD64_IBSOPDATA4, *buf++);
+				size++;
+			}
 		}
-		if (ibs_caps & IBS_CAPS_OPDATA4) {
-			rdmsrl(MSR_AMD64_IBSOPDATA4, *buf++);
+		if (perf_ibs == &perf_ibs_fetch && (ibs_caps & IBS_CAPS_FETCHCTLEXTD)) {
+			rdmsrl(MSR_AMD64_ICIBSEXTDCTL, *buf++);
 			size++;
 		}
 	}
diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h
index 2859ee4f39a8..b08c8a2afc0e 100644
--- a/arch/x86/include/asm/msr-index.h
+++ b/arch/x86/include/asm/msr-index.h
@@ -464,6 +464,7 @@ 
 #define MSR_AMD64_IBSOP_REG_MASK	((1UL<<MSR_AMD64_IBSOP_REG_COUNT)-1)
 #define MSR_AMD64_IBSCTL		0xc001103a
 #define MSR_AMD64_IBSBRTARGET		0xc001103b
+#define MSR_AMD64_ICIBSEXTDCTL		0xc001103c
 #define MSR_AMD64_IBSOPDATA4		0xc001103d
 #define MSR_AMD64_IBS_REG_COUNT_MAX	8 /* includes MSR_AMD64_IBSBRTARGET */
 #define MSR_AMD64_SEV			0xc0010131