From: Kim Phillips <kim.phillips@amd.com>
Date: Tue, 8 Sep 2020 21:47:38 +0000 (-0500)
Subject: perf/x86/amd/ibs: Fix raw sample data accumulation
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=36e1be8ada994d509538b3b1d0af8b63c351e729;p=linux.git

perf/x86/amd/ibs: Fix raw sample data accumulation

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.

Fixes: 904cb3677f3a ("perf/x86/amd/ibs: Update IBS MSRs and feature definitions")
Reported-by: Stephane Eranian <stephane.eranian@google.com>
Signed-off-by: Kim Phillips <kim.phillips@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20200908214740.18097-6-kim.phillips@amd.com
---

diff --git a/arch/x86/events/amd/ibs.c b/arch/x86/events/amd/ibs.c
index 863174ac0de37..cfbd020320ec2 100644
--- a/arch/x86/events/amd/ibs.c
+++ b/arch/x86/events/amd/ibs.c
@@ -630,18 +630,24 @@ fail:
 				       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 dc131b84ac3a5..2d39c31745249 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