From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6DB88382F03 for ; Fri, 7 Aug 2026 14:38:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=148.163.156.1 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786113491; cv=none; b=V1v6moC1xcmxbyAs5+y0G2shQCcYUNMc1CR2wmzRUvsvnvQdU95ZteyltqXna2q1GiAWcj3zRRPyuJQt1e7E8q7me7W5vS+Cy9kP4wX/8t8BZgFz+rzEmVCEaDCMFdxZ6QuCnlTkEVybnnRIURnkTCYwkIjug2WwXg5dVesvP8E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786113491; c=relaxed/simple; bh=4UDXjDBdnlJvaz2NjhVErEtFGqXrdrUH8Q7jCuUs6FM=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version:Content-Type; b=XfSun7xiNxHmByo4NbWPQqBP4p9s0sWe1LeNiHzSgEmMrkMsU16xJ3KQU7xc/EVF33vn+i+rrziMtMv9/a5bKQI3ZhGlCthpAJRJ9FouuoKD4iTlviPwOSFYDcMN1eQu3leHcADAGKTQ3/I7iwPEKN7kz5A7u8DsGn/2O0gqIhg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.ibm.com; spf=pass smtp.mailfrom=linux.ibm.com; dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com header.b=mTi6sujP; arc=none smtp.client-ip=148.163.156.1 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.ibm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.ibm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com header.b="mTi6sujP" Received: from pps.filterd (m0360083.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.18.1.11/8.18.1.11) with ESMTP id 677ClbQM1485050; Fri, 7 Aug 2026 14:37:59 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=cc :content-transfer-encoding:content-type:date:from:message-id :mime-version:subject:to; s=pp1; bh=wJ/W/Fi1b/6h4ADYkcco/0/E7e58 RC8K+goVg5EQT5s=; b=mTi6sujPRoyMbfEfQByezRB0K8AI5pVGSjAryh/D8ZXl WG8iUeUEjgV85R9Ma+VuoOqvG0tXXod2TpH/kDH2bRWRVOTO+/ruP6yVkLhDcLOz qDFhUwjt0a3XJlD5DIgIPlPoJ5WbF0fUnOXh27B4Sga2nxZXdTan2G7XwuSZBzA9 Twl9aLp77gDxEBFNyojGa2v/bph57pFNbIN7R0YKcYxQCN4rmCjtY27qt38CzxWs N6XDo4+60ZTYbAz1s4A8JrqeWjVwAJ/1n80j1ldTRt82Kv4UEqNrw8hOpOsfko+S 1WNZ/RpIWZfVSFi7FEO1XGR1QjRqZZ75yKnoGb+4uw== Received: from ppma12.dal12v.mail.ibm.com (dc.9e.1632.ip4.static.sl-reverse.com [50.22.158.220]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 4fvy044bp6-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 07 Aug 2026 14:37:59 +0000 (GMT) Received: from pps.filterd (ppma12.dal12v.mail.ibm.com [127.0.0.1]) by ppma12.dal12v.mail.ibm.com (8.18.1.7/8.18.1.7) with ESMTP id 677EQKnQ003677; Fri, 7 Aug 2026 14:37:58 GMT Received: from smtprelay02.fra02v.mail.ibm.com ([9.218.2.226]) by ppma12.dal12v.mail.ibm.com (PPS) with ESMTPS id 4fsu4r05w3-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 07 Aug 2026 14:37:58 +0000 (GMT) Received: from smtpav03.fra02v.mail.ibm.com (smtpav03.fra02v.mail.ibm.com [10.20.54.102]) by smtprelay02.fra02v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 677Ebrkr47841670 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 7 Aug 2026 14:37:53 GMT Received: from smtpav03.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 1CF1820043; Fri, 7 Aug 2026 14:37:53 +0000 (GMT) Received: from smtpav03.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id C5C7A20040; Fri, 7 Aug 2026 14:37:50 +0000 (GMT) Received: from localhost.localdomain (unknown [9.39.25.17]) by smtpav03.fra02v.mail.ibm.com (Postfix) with ESMTP; Fri, 7 Aug 2026 14:37:50 +0000 (GMT) From: Athira Rajeev To: linuxppc-dev@lists.ozlabs.org, maddy@linux.ibm.com Cc: linux-perf-users@vger.kernel.org, atrajeev@linux.ibm.com, hbathini@linux.vnet.ibm.com, tejas05@linux.ibm.com, venkat88@linux.ibm.com, tshah@linux.ibm.com, usha.r2@ibm.com Subject: [PATCH V5 0/6] powerpc/perf: Add HTM PMU driver and perf AUX support Date: Fri, 7 Aug 2026 20:07:28 +0530 Message-Id: <20260807143734.1224-1-atrajeev@linux.ibm.com> X-Mailer: git-send-email 2.39.5 (Apple Git-154) Precedence: bulk X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwODA3MDExMiBTYWx0ZWRfX4MJ32JQrns8/ BmsHUsgh7WA85IG05FXXsuXje5QZejuS+dlIAWpIb3f0YToLE4rxKlJDGh3EF79WRtlNlLivUU6 VInL3LsL0Ufe9UiuzaNY6pbUcBTEAnSSZ0/DJXSeJr5vpaCugA3vX2BYbOPSMmDPAJ6XEvI83+X /D1MVtkSwlw6mZrVVUt+KUaNjAlF+bdPhEdBXDu5CvE0sSi5QOrZnzt3QmGYnaMBXdh+/pmYY9y UJ4QU1g2zTJM9zXLIP710B5SmlgQiSSWB+H/TA0yCpMShI2qixGOICmQmXN7+UAiyQ4Yzjb/3Ov 74vu2vHTgA22bZI5yc0LzVfukKkrN3x1TV/Gq97tJenbxXmZQNR6n8I674zPbSJO1k1F/5zAfc0 yMKZ0L3GIanGIUEd8CuD27Qp1uAxEwjkbis7rJgyJzpsEAP+BKQjl1oZpqcEf6Pu1TuRAULM/0/ 8XHd+82Z5Ml9XPfCLIQ== X-Proofpoint-ORIG-GUID: 3-i9myEIUdNLOkixxB8aUptZBeSJh4TZ X-Proofpoint-GUID: 3-i9myEIUdNLOkixxB8aUptZBeSJh4TZ X-Proofpoint-Spam-Info: AW1haW4tMjYwODA3MDExMiBTYWx0ZWRfX6HELR9eLDLGu wbDm9yOR88A8xs0Sc79PQxoORbBqK0Nv2O5tryfsJkQ8oBPVHIqWjsz5a/6U64/lqUivGYWDfQI KwQq0DtXm/hSMNAJjMALzcuS8kb7fck= X-Authority-Analysis: v=2.4 cv=WLpPmHsR c=1 sm=1 tr=0 ts=6a75edc7 cx=c_pps a=bLidbwmWQ0KltjZqbj+ezA==:117 a=bLidbwmWQ0KltjZqbj+ezA==:17 a=IkcTkHD0fZMA:10 a=Sv0fKeRqtYgA:10 a=VkNPw1HP01LnGYTKEx00:22 a=RnoormkPH1_aCDwRdu11:22 a=iQ6ETzBq9ecOQQE5vZCe:22 a=zQHK5bSOx5GkbYARfgoA:9 a=QEXdDO2ut3YA:10 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1176,Hydra:6.1.134,FMLib:17.12.100.49 definitions=2026-08-07_02,2026-08-06_01,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 bulkscore=0 lowpriorityscore=0 adultscore=0 malwarescore=0 clxscore=1015 impostorscore=0 priorityscore=1501 phishscore=0 suspectscore=0 spamscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2606150000 definitions=main-2608070112 Overview: The Hardware Trace Macro (HTM) on POWER systems provides hardware-level bus-trace data for a specific node/chip/core target within a logical partition. It is accessed via the H_HTM hypervisor call and traces continuously at node, chip, or core scope independent of task scheduling. This series adds a new "htm" PMU driver under arch/powerpc/perf/ that exposes HTM trace collection via the standard perf interface using the perf AUX buffer infrastructure, together with ABI and RST documentation. Patch overview: Patch 1 introduces the core HTM PMU driver (htm-perf.c). The event configuration encodes the trace target as a 28-bit value in perf_event_attr.config: bits 0-3: htm_type (HTM_CORE=2, HTM_NEST=1, HTM_LLAT=3) bits 4-11: nodeindex bits 12-19: nodalchipindex bits 20-27: coreindexonchip The PMU lifecycle maps to H_HTM_OP_CONFIGURE/DECONFIGURE at add/del time and H_HTM_OP_START/STOP at start/stop time. Context-switch callbacks (PERF_EF_RELOAD / PERF_EF_UPDATE) are intentionally ignored because HTM traces the hardware scope, not individual tasks. Tracing state is kept in event->pmu_private (HTM_TRACING_ACTIVE / HTM_TRACING_INACTIVE) as the authoritative source, with event->hw.state kept in sync as a hint for the perf core. Patch 2 adds duplicate-reservation protection. When 'perf record -a' is used, perf opens system-wide events on all CPUs in parallel. Without driver-side tracking, concurrent opens for the same HTM target (node, chip, core, type) can race and issue duplicate H_HTM_OP_CONFIGURE flows. A global reserved-targets list is added; htm_event_init() rejects any open that matches an already-reserved tuple, while different targets can still be opened simultaneously on different CPUs. Patch 3 adds AUX ring-buffer support so that high-volume trace data can be streamed into a perf AUX buffer. The driver opts into PERF_PMU_CAP_AUX_NO_SG | PERF_PMU_CAP_AUX_PREFER_LARGE to request physically contiguous allocations, which H_HTM_OP_DUMP_DATA requires. A page-by-page physical-continuity scan is performed before each dump to detect and bound any fragmentation gaps, preventing silent memory corruption. event->count is set to the number of 128-byte HTM trace records written on a successful dump, 1 when the AUX buffer is temporarily full but the hypervisor stream is intact, and 0 when the stream is exhausted or a hard error occurs; the perf tool uses this as a drain signal to decide whether another read pass is needed before closing the event. Patch 4 adds system memory configuration capture. After writing trace data to the AUX buffer, htm_event_read() calls H_HTM_OP_DUMP_SYSMEM_CONF and emits the returned physical-to-logical address mapping records as PERF_SAMPLE_RAW data. Keeping trace data in the AUX stream and memory configuration in raw samples allows each to be decoded independently in userspace. Patch 5 adds ABI documentation for the sysfs entries under /sys/bus/event_source/devices/htm/, covering the format attribute (config bit layout) and the events attribute group. Patch 6 extends Documentation/arch/powerpc/htm.rst with a new section on the perf interface: event syntax, required options, the two output files (htm.bin.nX.pX.cX.tX and translation.nX.pX.cX.tX), and how to pass them to htmdecode for trace decoding. Usage example: Collect HTM trace data from two simultaneous chip targets: # perf record -m,256 \ -e htm/nodalchipindex=2,nodeindex=0,htm_type=1,cpu=8/ \ -e htm/nodalchipindex=1,nodeindex=0,htm_type=1,cpu=9/ \ -a -- sleep 10 # perf report Output files written by perf report: htm.bin.n0.p2.c0.t1 raw HTM bus-trace, chip 2 htm.bin.n0.p1.c0.t1 raw HTM bus-trace, chip 1 translation.n0.p2.c0.t1 memory config records, chip 2 translation.n0.p1.c0.t1 memory config records, chip 1 The htm.bin.* files can then be decoded with htmdecoder to produce trace output. Testing: Tested on POWER11 with two simultaneous HTM targets. Both htm.bin.* and translation.* files are produced correctly. # perf record -C 9 -m,256 \ -e htm/nodalchipindex=2,nodeindex=0,htm_type=1/ -a sleep 3 [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 256.277 MB perf.data ] # perf record -m,512 \ -e htm/htm_type=3,nodalchipindex=1,nodeindex=0,coreindexonchip=6,cpu=8/ \ -e htm/htm_nest,nodalchipindex=1,nodeindex=0,cpu=16/ -a sleep 1 [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 514.095 MB perf.data ] Athira Rajeev (6): powerpc/perf: Add HTM PMU driver to expose Hardware Trace Macro data powerpc/perf: Reject duplicate HTM target reservations powerpc/perf: Add AUX buffer management to capture HTM trace data powerpc/perf: Capture the HTM memory configuration as part of perf data docs: ABI: sysfs-bus-event_source-devices-htm: Document sysfs event format entries for htm pmu powerpc/perf/htm: Add documentation for Hardware Trace Macro PMU .../sysfs-bus-event_source-devices-htm | 36 + Documentation/arch/powerpc/htm.rst | 158 ++- arch/powerpc/perf/Makefile | 2 +- arch/powerpc/perf/htm-perf.c | 1122 +++++++++++++++++ 4 files changed, 1314 insertions(+), 4 deletions(-) create mode 100644 Documentation/ABI/testing/sysfs-bus-event_source-devices-htm create mode 100644 arch/powerpc/perf/htm-perf.c -- 2.53.0