From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx0b-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) (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 04A3A388880; Thu, 13 Aug 2026 09:46:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=148.163.158.5 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786614365; cv=none; b=anbWIgqEcvVlvACzT9+QgPybCvjKEqBDJTwtQ6M5PpbICA+1vG75q/699ySqyoEh9NcfJgxv+PB9rp9KOcI+o7nq7wWjAeODsAK/2faNAmiZd0eha4ZWruMbS5N4dzmsR6fRMRxxI56TgQxA1+Ktqzr2ngHqpAVM8AvbiuO7IC8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786614365; c=relaxed/simple; bh=E7cpcLlmdHz/JVpyc3lcptNDixrl9wnrlRMimDoIxl4=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=pAih2JTeYUBSqp7LwHowACIZ00tdBuGBkauvZM1dVBemR0Pm7DvllI/WPWAQYP7NGVl/UHqorR9PWh+rPF9WDzwwp9btd3wX/rO/OkgHejqOSlT30K8t+Ae2VSJYgU/mWYzitDaVFVOEsE68W9gj8buKI++H4Cb2BJciHPdEmmM= 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=R4pZneih; arc=none smtp.client-ip=148.163.158.5 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="R4pZneih" Received: from pps.filterd (m0353725.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.18.1.11/8.18.1.11) with ESMTP id 67D98x0c811213; Thu, 13 Aug 2026 09:45:48 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=cc :content-transfer-encoding:date:from:message-id:mime-version :subject:to; s=pp1; bh=U/U4gNffHLdPUWX384p/FMq5oq6FLru5o4PpaR4Sm xw=; b=R4pZneihKmTt+x757r3d69MSrwXl5+1FM8yOOStjNOaofAh+g5z7rWqJ5 YXfZSU1ZHIGamTwPW3I2GzytX/3IRL2vEQjKQ9LuMX9kzpzbWBJkYuaNql2ha8Im bAY06DTW5qg2FR56XW2Jlj1D9ZxIUBsmA8M1UBK9yHnSQJ1YOg1bM1X0yO73ke2Z BvpgtTIT03gVn94/8dyLkVll4Bd5VJTRxCXVtGWJtMJo7Pn4WA4naEvBNgu37b3A EkW1l7zmkJmgNw3asY2JRqDODzZNdgZlpQ2qh8sSlNIgkjQaVPweZ9hmKG/TyMQJ ac4PFouJ5u/isIacUdTF2sd1Yt7Tw== Received: from ppma13.dal12v.mail.ibm.com (dd.9e.1632.ip4.static.sl-reverse.com [50.22.158.221]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 4fyb23ymx2-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 13 Aug 2026 09:45:48 +0000 (GMT) Received: from pps.filterd (ppma13.dal12v.mail.ibm.com [127.0.0.1]) by ppma13.dal12v.mail.ibm.com (8.18.1.7/8.18.1.7) with ESMTP id 67D9fGpv018318; Thu, 13 Aug 2026 09:45:47 GMT Received: from smtprelay03.fra02v.mail.ibm.com ([9.218.2.224]) by ppma13.dal12v.mail.ibm.com (PPS) with ESMTPS id 4fxh0gjawb-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 13 Aug 2026 09:45:47 +0000 (GMT) Received: from smtpav02.fra02v.mail.ibm.com (smtpav02.fra02v.mail.ibm.com [10.20.54.101]) by smtprelay03.fra02v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 67D9jhLX31785364 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 13 Aug 2026 09:45:43 GMT Received: from smtpav02.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 59E772004B; Thu, 13 Aug 2026 09:45:43 +0000 (GMT) Received: from smtpav02.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 020E520040; Thu, 13 Aug 2026 09:45:41 +0000 (GMT) Received: from localhost.localdomain (unknown [9.39.17.189]) by smtpav02.fra02v.mail.ibm.com (Postfix) with ESMTP; Thu, 13 Aug 2026 09:45:40 +0000 (GMT) From: Gautam Menghani To: maddy@linux.ibm.com, atrajeev@linux.ibm.com, npiggin@gmail.com, mpe@ellerman.id.au, chleroy@kernel.org Cc: Gautam Menghani , linuxppc-dev@lists.ozlabs.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 0/3] powerpc/perf: Fix vpa-pmu driver to report correct numbers Date: Thu, 13 Aug 2026 15:15:29 +0530 Message-ID: <20260813094535.10083-1-gautam@linux.ibm.com> X-Mailer: git-send-email 2.50.1 Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 X-Proofpoint-Reinject: loops=2 maxloops=12 X-Authority-Analysis: v=2.4 cv=XqfK/1F9 c=1 sm=1 tr=0 ts=6a7d924c cx=c_pps a=AfN7/Ok6k8XGzOShvHwTGQ==:117 a=AfN7/Ok6k8XGzOShvHwTGQ==:17 a=Sv0fKeRqtYgA:10 a=VkNPw1HP01LnGYTKEx00:22 a=RnoormkPH1_aCDwRdu11:22 a=V8glGbnc2Ofi9Qvn3v5h:22 a=2wL9yz101uEFEcatHFYA:9 X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwODEzMDA2NiBTYWx0ZWRfX6gmCqVpDCrrv IWi1CGa16WotAhKVgfGQThtJ0RomSkkxGwl1G255d6hhx6xr/20fwBFDOmRZFCVpc2FibEp7L1Z dvRVIwFKEl0R7EP8PFiTSj2+QAwjivm51G8D8+JPa7Ea86H0+BOTRtLRreifDgHWv7ybvESbr7u 5Omacbth/3ZQX6sD5+R8CsjjeV/B8g/9VstRG7ljd4+2ASTANlc/u4ur26bViQAmE3XWNlPB39Y ph2tRPJfZXC3xvX2LHv7AyJXxjzm5iNkCrQRKO6ICNk3y4ntgZbCmAvu8ElypCI6SkCv0f8mvUu 5yRXNOB4EgTiIPuTV6xTrd9823EvuBMjwM3h+OJG389LcdqKl5jJBi6wciOJScL+Cx4ZicjD2+h 7y7aBwf9D4SKgh0e8jMArC4PzfPwa8i5GfezYlPDuCNPj6DpwZGNPmQuXQPg+/o0ddgOH5+XdbM UKkUYIdr5HAkyD1Cl1w== X-Proofpoint-ORIG-GUID: ID7kYmrJxcWXZHrqcgLaWReLcQmOSBY7 X-Proofpoint-GUID: AbZaUBK5c7U3HdG4ZewI4kU9M2eop95W X-Proofpoint-Spam-Info: AW1haW4tMjYwODEzMDA2NiBTYWx0ZWRfXxMhu3+nsu6Uj pvCIWMSGmwE7RDDu/r7mx0/V0dX8dVCm6PzM0J/TUOuHQmTeBk1wowBXVZRXZfla+p8iY0eP5eL mgo24AGxnJOdipNJnbL+l3b86KCAzBM= 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=2026-08-13_03,2026-08-12_01,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 lowpriorityscore=0 spamscore=0 adultscore=0 malwarescore=0 clxscore=1015 suspectscore=0 priorityscore=1501 impostorscore=0 phishscore=0 bulkscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2606150000 definitions=main-2608130066 The vpa-pmu driver can sometimes report incorrect context switch latency numbers: $ perf stat -e vpa_pmu/l1_to_l2_lat/ --tid=2061 -I 1000 time counts unit events 1.001022517 18,446,744,073,708,177,408 vpa_pmu/l1_to_l2_lat/ 2.002120674 345,092 vpa_pmu/l1_to_l2_lat/ 3.003171582 406,342 vpa_pmu/l1_to_l2_lat/ 4.004234838 340,836 vpa_pmu/l1_to_l2_lat/ These invalid numbers are observed because the vpa-pmu driver does not handle the following scenarios: 1. The vCPU process gets rescheduled to a different host cpu. 2. The vCPU process is not running, and vpa_pmu_read() is called to read counter values. Fix the above cases by maintaining aggregate counter values inside the vcpu->arch struct and using them to report data. changes in v2: 1. Fix the output for "perf stat --cpu ..." 2. Add stable and fixes tags Gautam Menghani (3): KVM: PPC: Book3S HV: Maintain aggregate context switch values for vCPUs powerpc/perf: Use the aggregate context switch values from vcpu struct powerpc/perf: Update prev_count of event to get accurate values arch/powerpc/include/asm/kvm_book3s_64.h | 3 -- arch/powerpc/kvm/book3s_hv.c | 51 ++---------------------- arch/powerpc/perf/vpa-pmu.c | 25 +++++++++--- 3 files changed, 22 insertions(+), 57 deletions(-) -- 2.54.0