From patchwork Wed Apr 20 11:34:28 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pierre Morel X-Patchwork-Id: 12820113 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 20F39C433F5 for ; Wed, 20 Apr 2022 11:40:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1378187AbiDTLm5 (ORCPT ); Wed, 20 Apr 2022 07:42:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48590 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1352651AbiDTLmz (ORCPT ); Wed, 20 Apr 2022 07:42:55 -0400 Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8DD4A1FCC7; Wed, 20 Apr 2022 04:40:09 -0700 (PDT) Received: from pps.filterd (m0098396.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.1.2/8.16.1.2) with SMTP id 23K9KJMt024487; Wed, 20 Apr 2022 11:40:09 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=from : to : cc : subject : date : message-id : mime-version : content-transfer-encoding; s=pp1; bh=FOWMJaKcBmxHsdy9nbpnE+qHGCZ33g0Dy6GQGJuQGv0=; b=rNQMmkJP1GPp+Ex5ZLfM+n8HS/QptDTsVOkVlegToRv0YrheS1DIHUu7Fnk23Hkt6HpW 5Ln7zj9Knty10a3lcyQGDb/Hgq60BhVNAPla6DuYEP/DkvTeP8I9yoSqUE5LDQbfvXJK nUDPJhCWKpMo7xhATe+KcRYsgR3GRCGt1+1FCcM09aU4Yk/zy/g6viMHJuverW0wDKhG H1zTejwVqBYWgxhowo5jvp/u3j0y5/lJLlzjvPQoCjKR6MIUGM4txECk6cqiFVDXkM7C EI7sY9AtM9XOb32SHb6MQseWoUhnEK68nuqhZn9Q4Yih/+lptn5MXmg+IIyJdAsnAOLW 6g== Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com with ESMTP id 3fjff2tnh8-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 20 Apr 2022 11:40:09 +0000 Received: from m0098396.ppops.net (m0098396.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.43/8.16.0.43) with SMTP id 23KAjQLm017970; Wed, 20 Apr 2022 11:40:08 GMT Received: from ppma02fra.de.ibm.com (47.49.7a9f.ip4.static.sl-reverse.com [159.122.73.71]) by mx0a-001b2d01.pphosted.com with ESMTP id 3fjff2tng6-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 20 Apr 2022 11:40:08 +0000 Received: from pps.filterd (ppma02fra.de.ibm.com [127.0.0.1]) by ppma02fra.de.ibm.com (8.16.1.2/8.16.1.2) with SMTP id 23KBROga029774; Wed, 20 Apr 2022 11:31:17 GMT Received: from b06cxnps4076.portsmouth.uk.ibm.com (d06relay13.portsmouth.uk.ibm.com [9.149.109.198]) by ppma02fra.de.ibm.com with ESMTP id 3fgu6u3bsr-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 20 Apr 2022 11:31:17 +0000 Received: from d06av21.portsmouth.uk.ibm.com (d06av21.portsmouth.uk.ibm.com [9.149.105.232]) by b06cxnps4076.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 23KBVEGg33817080 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 20 Apr 2022 11:31:14 GMT Received: from d06av21.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 2A60052059; Wed, 20 Apr 2022 11:31:14 +0000 (GMT) Received: from li-c6ac47cc-293c-11b2-a85c-d421c8e4747b.ibm.com.com (unknown [9.171.58.217]) by d06av21.portsmouth.uk.ibm.com (Postfix) with ESMTP id 7194D5204F; Wed, 20 Apr 2022 11:31:13 +0000 (GMT) From: Pierre Morel To: kvm@vger.kernel.org Cc: linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, borntraeger@de.ibm.com, frankja@linux.ibm.com, cohuck@redhat.com, david@redhat.com, thuth@redhat.com, imbrenda@linux.ibm.com, hca@linux.ibm.com, gor@linux.ibm.com, pmorel@linux.ibm.com, wintera@linux.ibm.com, seiden@linux.ibm.com, nrb@linux.ibm.com Subject: [PATCH v8 0/2] s390x: KVM: CPU Topology Date: Wed, 20 Apr 2022 13:34:28 +0200 Message-Id: <20220420113430.11876-1-pmorel@linux.ibm.com> X-Mailer: git-send-email 2.27.0 MIME-Version: 1.0 X-TM-AS-GCONF: 00 X-Proofpoint-GUID: g4aqulNEI10u-YXs4DIdOon25_AuB94Z X-Proofpoint-ORIG-GUID: 0VzG0B7ww_JgPTZYzSGRioIsDrDdXcGC X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.858,Hydra:6.0.486,FMLib:17.11.64.514 definitions=2022-04-20_03,2022-04-20_01,2022-02-23_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 impostorscore=0 mlxlogscore=999 adultscore=0 clxscore=1015 lowpriorityscore=0 malwarescore=0 bulkscore=0 phishscore=0 suspectscore=0 priorityscore=1501 mlxscore=0 spamscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2202240000 definitions=main-2204200071 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Hi all, This new spin adds reset handling and bug correction to the series for the implementation of interpretation for the PTF instruction. The series provides: 1- interception of the STSI instruction forwarding the CPU topology 2- interpretation of the PTF instruction 3- a KVM capability for the userland hypervisor to ask KVM to setup PTF interpretation. 0- Foreword The S390 CPU topology is reported using two instructions: - PTF, to get information if the CPU topology did change since last PTF instruction or a subsystem reset. - STSI, to get the topology information, consisting of the topology of the CPU inside the sockets, of the sockets inside the books etc. The PTF(2) instruction report a change if the STSI(15.1.2) instruction will report a difference with the last STSI(15.1.2) instruction*. With the SIE interpretation, the PTF(2) instruction will report a change to the guest if the host sets the SCA.MTCR bit. *The STSI(15.1.2) instruction reports: - The cores address within a socket - The polarization of the cores - The CPU type of the cores - If the cores are dedicated or not We decided to implement the CPU topology for S390 in several steps: - first we report CPU hotplug - modification of the CPU mask inside sockets In future development we will provide: - handling of shared CPUs - reporting of the CPU Type - reporting of the polarization 1- Interception of STSI To provide Topology information to the guest through the STSI instruction, we forward STSI with Function Code 15 to the userland hypervisor which will take care to provide the right information to the guest. To let the guest use both the PTF instruction to check if a topology change occurred and sthe STSI_15.x.x instruction we add a new KVM capability to enable the topology facility. 2- Interpretation of PTF with FC(2) The PTF instruction will report a topology change if there is any change with a previous STSI(15.1.2) SYSIB. Changes inside a STSI(15.1.2) SYSIB occur if CPU bits are set or clear inside the CPU Topology List Entry CPU mask field, which happens with changes in CPU polarization, dedication, CPU types and adding or removing CPUs in a socket. The reporting to the guest is done using the Multiprocessor Topology-Change-Report (MTCR) bit of the utility entry of the guest's SCA which will be cleared during the interpretation of PTF. To check if the topology has been modified we use a new field of the arch vCPU prev_cpu, to save the previous real CPU ID at the end of a schedule and verify on next schedule that the CPU used is in the same socket, this field is initialized to -1 on vCPU creation. Regards, Pierre Pierre Morel (2): s390x: KVM: guest support for topology function s390x: KVM: resetting the Topology-Change-Report Documentation/virt/kvm/api.rst | 16 +++ arch/s390/include/asm/kvm_host.h | 12 ++- arch/s390/include/uapi/asm/kvm.h | 9 ++ arch/s390/kvm/kvm-s390.c | 177 ++++++++++++++++++++++++++++++- arch/s390/kvm/kvm-s390.h | 25 +++++ arch/s390/kvm/priv.c | 14 ++- arch/s390/kvm/vsie.c | 3 + include/uapi/linux/kvm.h | 1 + 8 files changed, 249 insertions(+), 8 deletions(-)