From patchwork Wed Dec 19 19:17:41 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Mueller X-Patchwork-Id: 10737979 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 24B58746 for ; Wed, 19 Dec 2018 19:18:11 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1511020950 for ; Wed, 19 Dec 2018 19:18:11 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 08299262AE; Wed, 19 Dec 2018 19:18:11 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6424720950 for ; Wed, 19 Dec 2018 19:18:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728872AbeLSTSI (ORCPT ); Wed, 19 Dec 2018 14:18:08 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:33462 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728711AbeLSTSI (ORCPT ); Wed, 19 Dec 2018 14:18:08 -0500 Received: from pps.filterd (m0098421.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id wBJJ0MP0123711 for ; Wed, 19 Dec 2018 14:18:07 -0500 Received: from e06smtp05.uk.ibm.com (e06smtp05.uk.ibm.com [195.75.94.101]) by mx0a-001b2d01.pphosted.com with ESMTP id 2pfswseyuk-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Wed, 19 Dec 2018 14:18:07 -0500 Received: from localhost by e06smtp05.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Wed, 19 Dec 2018 19:18:01 -0000 Received: from d06av21.portsmouth.uk.ibm.com (d06av21.portsmouth.uk.ibm.com [9.149.105.232]) by b06cxnps3074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id wBJJHxsW51314754 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Wed, 19 Dec 2018 19:18:00 GMT Received: from d06av21.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id BF13352050; Wed, 19 Dec 2018 19:17:59 +0000 (GMT) Received: from s38lp84.lnxne.boe (unknown [9.152.108.100]) by d06av21.portsmouth.uk.ibm.com (Postfix) with ESMTP id 6CA375204E; Wed, 19 Dec 2018 19:17:59 +0000 (GMT) From: Michael Mueller To: KVM Mailing List Cc: Linux-S390 Mailing List , linux-kernel@vger.kernel.org, kvm390-list@tuxmaker.boeblingen.de.ibm.com, Martin Schwidefsky , Heiko Carstens , Christian Borntraeger , Janosch Frank , David Hildenbrand , Cornelia Huck , Halil Pasic , Pierre Morel , Michael Mueller Subject: [PATCH v5 00/15] KVM: s390: make use of the GIB Date: Wed, 19 Dec 2018 20:17:41 +0100 X-Mailer: git-send-email 2.13.4 X-TM-AS-GCONF: 00 x-cbid: 18121919-0020-0000-0000-000002F9F02A X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18121919-0021-0000-0000-00002149FDD5 Message-Id: <20181219191756.57973-1-mimu@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-12-19_10:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1812190150 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The Guest Information Area (GIB) and its mechanics is part of the AIV facility. It provides hardware support to process Adapter Interruptions (AI) for pagable storage mode guests. Whenever a guest cannot process an AI because none of its vcpus is running in SIE context, a GIB alert interruption is sent to and handled by the host program to dispatch a vcpu of the respective guest. Eventually, the AI is handled by the guest. v4->v5: Between these two versions some significant change was introduced: a) During IPM look-up, the IAM gets atomically restored if the IPM is clean. (The main strategy is: As soon no airqs are pending anymore, get prepared for new ones arriving). b) Kick a set of vcpus in WAIT state, that will be able to handle all ISCs in IPM if possible. The main loop that processes the GIB alert list is unchanged. patches 1/15 to 6/15: prepare the existing Interruption and GISA code for the introduction of the GIB code. patches 7/15 to 9/15: kept from v4. patch 10/15: restores the IAM in get_ipm() when clean on request with additional parameter irq_flags patch 12/15: modifies kvm_s390_deliver_pending_interrupts() such that the IAM is not restored during the deliverable_irqs() test as we are about to enter the SIE. Restoring the IAM would trigger the alert mechanism unnecessarily on SIE entry. patch 13/15: process_gib_alert_list() now triggers a minimal set of idle vcpus capable the handle all pending ISCs. patch 14/15: the wiring is logical similar to v4 but uses different routines patch 15/15: kept from v4. v3->v4: The central change of v4 is that the metric "vcpus_in_sie" has been dropped. A least agressive IAM restore strategy is being followed now. The consequence is that potentially more GAL interruptions are to be handled by the host program. The assuption as made that as soon the first vcpu is trying to go into wait state, this could be the last vcpu being open for I/O interruptions. Thus, to not loose the initiative to deliver I/O interruptions as soon as possible, the IAM is restored. Adding better heuristics can be done in future. I expect this to be the last version of the series. patch 01/12: Kernel msg now printed when FLIC fails to register during arch inititialization. patch 03/12: Commit message slightly changed with the hint that gib initialization is called by last patch of this serias. patch 09/12: IAM now restored during kvm_s390_handle_wait() patch 10/12: gib destroy case now handled upon unsuccessful arch inititialization. All other patches are unchanged. v2->v3: patch 01/12: Fixes a resource dealocation issue upon unsuccessful exit from kvm_arch_init(). It is relevant for patch 11/12 as well. patch 08/12: The function process_gib_alert_list() has been rewritten to reduce the number of GAL interruptions on the host for many guest scenarios. patch 10/12: The IAM is now never cleared before SIE entry. It will be cleared by millicode as soon the first guest interruption is made pending and not directly processed in SIE. The IAM gets restored as soon a vm is idle, i.e. no vcpu of that guest is in SIE context anymore. patch 11/12: now integrates with new patch 01/12 patch 12/12: This patch is just experimental and shall not be part of the final series. The first patch of series v2: "leave AIs in IPM of GISA during vcpu_pre_run()" has been dropped. All other patches are unchanged. v1->v2: patch 01/12: New patch. Tt can go also standalone without the rest of the GIB series presented here but is a requirement patch 03/12: kvm_s390_gib_init() now has a return code patch 06/12: unlink_gib_alert_list() now uses cmpxchg() instead of atomic_xchg() patch 08/12: New patch. Foctors out __find_vcpu_for_floating_irq() patch 09/12: process_gib_alert_list() has been simplified the GISA clear/destroy cases have been removed patch 11/12: kvm_s390_gisa_clear/destroy() now clear the IAM and process the alert list directly The IAM now gets restored in vcpu_post_run() only if the GISA is not in alert list patch 12/12: during kvm_arch_init() now the return code of kvm_s390_gib_init() is honored. All other patches are unchanged. Michael Mueller (15): KVM: s390: unregister debug feature on failing arch init KVM: s390: coding style issue kvm_s390_gisa_init/clear() KVM: s390: factor out nullify_gisa() KVM: s390: use pending_irqs_no_gisa() where appropriate KVM: s390: unify pending_irqs() and pending_irqs_no_gisa() KVM: s390: remove prefix kvm_s390_gisa_ from static inline functions s390/cio: add function chsc_sgib() KVM: s390: add the GIB and its related life-cyle functions KVM: s390: add kvm reference to struct sie_page2 KVM: s390: add functions to (un)register GISC with GISA KVM: s390: restore IAM in get_ipm() when IPM is clean KVM: s390: do not restore IAM immediately before SIE entry KVM: s390: add function process_gib_alert_list() KVM: s390: add and wire function gib_alert_irq_handler() KVM: s390: start using the GIB Documentation/kmsg/s390/kvm | 12 ++ arch/s390/include/asm/cio.h | 1 + arch/s390/include/asm/irq.h | 1 + arch/s390/include/asm/isc.h | 1 + arch/s390/include/asm/kvm_host.h | 22 ++- arch/s390/kernel/irq.c | 1 + arch/s390/kvm/interrupt.c | 396 +++++++++++++++++++++++++++++++++++---- arch/s390/kvm/kvm-s390.c | 25 ++- arch/s390/kvm/kvm-s390.h | 2 + drivers/s390/cio/chsc.c | 37 ++++ drivers/s390/cio/chsc.h | 1 + 11 files changed, 457 insertions(+), 42 deletions(-) create mode 100644 Documentation/kmsg/s390/kvm