perf/x86/amd/ibs: Fix raw sample data accumulation (36e1be8a) · Commits · 戴 / test

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: ("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

arch/x86/events/amd/ibs.c

+16 −10

Original line number	Diff line number	Diff line
		@@ -630,12 +630,13 @@ fail:
		perf_ibs->offset_max,
		offset + 1);
		} while (offset < offset_max);
		if (event->attr.sample_type & PERF_SAMPLE_RAW) {
		/*
		* Read IbsBrTarget and IbsOpData4 separately
		* 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) {
		if (perf_ibs == &perf_ibs_op) {
		if (ibs_caps & IBS_CAPS_BRNTRGT) {
		rdmsrl(MSR_AMD64_IBSBRTARGET, *buf++);
		size++;
		@@ -645,6 +646,11 @@ fail:
		size++;
		}
		}
		if (perf_ibs == &perf_ibs_fetch && (ibs_caps & IBS_CAPS_FETCHCTLEXTD)) {
		rdmsrl(MSR_AMD64_ICIBSEXTDCTL, *buf++);
		size++;
		}
		}
		ibs_data.size = sizeof(u64) * size;

		regs = *iregs;

arch/x86/include/asm/msr-index.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -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

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