From patchwork Tue Jul 25 14:37:18 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ilya Leoshkevich X-Patchwork-Id: 13326555 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 E3B55C04A6A for ; Tue, 25 Jul 2023 14:39:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233228AbjGYOj3 (ORCPT ); Tue, 25 Jul 2023 10:39:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49526 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233221AbjGYOjT (ORCPT ); Tue, 25 Jul 2023 10:39:19 -0400 Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C91C6E5A; Tue, 25 Jul 2023 07:39:15 -0700 (PDT) Received: from pps.filterd (m0353729.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 36PE8NaQ024121; Tue, 25 Jul 2023 14:39:15 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding; s=pp1; bh=4iaAqRxvvrM7Nof+QH+so3L417PxKTJQmFsCtSx/Sp4=; b=ErhVppO3NmJkpeYqEBfc6yLlzal5XzoOe1E/z6viwJd3GBezpciRxcrXPsWJ+tvw89qc Y7WWtEayUxpveXGS0dIpC64ynk00CHXBiSKwejoN4sFWg1JMXTt5K6N2pfA9E2bhtoZX Q8zXeqApfgErtF8HBHkfGOD6hR3jKrEUu+9dqDo7LwAbk+3H/aTSg+BVGxhY0NkaJuZ5 jTmSbreYNXdF7KPy5VSDwU6KhiZKjfSUSm+1Sd3o/jgpf1WC/AWGtx8xWIRDpmLEqYWH 8BMTu7vSlS84hF6S6uW3YUYdLkZ4ajn/CrOkUSURkP2ehOQAIXDsAMZTFQy0cL1ENpTt ig== Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 3s2942ch3s-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 25 Jul 2023 14:39:14 +0000 Received: from m0353729.ppops.net (m0353729.ppops.net [127.0.0.1]) by pps.reinject (8.17.1.5/8.17.1.5) with ESMTP id 36PE8hZ5026789; Tue, 25 Jul 2023 14:39:11 GMT 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 3s2942cgu8-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 25 Jul 2023 14:39:11 +0000 Received: from pps.filterd (ppma13.dal12v.mail.ibm.com [127.0.0.1]) by ppma13.dal12v.mail.ibm.com (8.17.1.19/8.17.1.19) with ESMTP id 36PEKVCS002278; Tue, 25 Jul 2023 14:39:04 GMT Received: from smtprelay02.fra02v.mail.ibm.com ([9.218.2.226]) by ppma13.dal12v.mail.ibm.com (PPS) with ESMTPS id 3s0unjcb5k-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 25 Jul 2023 14:39:04 +0000 Received: from smtpav04.fra02v.mail.ibm.com (smtpav04.fra02v.mail.ibm.com [10.20.54.103]) by smtprelay02.fra02v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 36PEd1sQ21693126 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 25 Jul 2023 14:39:01 GMT Received: from smtpav04.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 452A82004D; Tue, 25 Jul 2023 14:39:01 +0000 (GMT) Received: from smtpav04.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 110032004F; Tue, 25 Jul 2023 14:39:01 +0000 (GMT) Received: from heavy.boeblingen.de.ibm.com (unknown [9.155.200.166]) by smtpav04.fra02v.mail.ibm.com (Postfix) with ESMTP; Tue, 25 Jul 2023 14:39:01 +0000 (GMT) From: Ilya Leoshkevich To: Christian Borntraeger , Janosch Frank , Claudio Imbrenda , Heiko Carstens , Vasily Gorbik , Alexander Gordeev Cc: David Hildenbrand , Sven Schnelle , kvm@vger.kernel.org, linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, Jens Freimann , Ilya Leoshkevich Subject: [PATCH v4 3/6] KVM: s390: interrupt: Fix single-stepping kernel-emulated instructions Date: Tue, 25 Jul 2023 16:37:18 +0200 Message-ID: <20230725143857.228626-4-iii@linux.ibm.com> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230725143857.228626-1-iii@linux.ibm.com> References: <20230725143857.228626-1-iii@linux.ibm.com> MIME-Version: 1.0 X-TM-AS-GCONF: 00 X-Proofpoint-ORIG-GUID: 4EP310NNUGWlJRnM3uFuiLnt349EGDpH X-Proofpoint-GUID: VHsJ43cihOSk00GBnxaQTfCwASXHkAAc X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.254,Aquarius:18.0.957,Hydra:6.0.591,FMLib:17.11.176.26 definitions=2023-07-25_08,2023-07-25_01,2023-05-22_02 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 mlxscore=0 adultscore=0 spamscore=0 lowpriorityscore=0 malwarescore=0 suspectscore=0 phishscore=0 mlxlogscore=995 clxscore=1015 impostorscore=0 priorityscore=1501 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2306200000 definitions=main-2307250128 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Single-stepping a kernel-emulated instruction that generates an interrupt causes GDB to land on the instruction following it instead of the respective interrupt handler. The reason is that kvm_handle_sie_intercept(), after injecting the interrupt, also processes the PER event and arranges a KVM_SINGLESTEP exit. The interrupt is not yet delivered, however, so the userspace sees the next instruction. Fix by avoiding the KVM_SINGLESTEP exit when there is a pending interrupt. The next __vcpu_run() loop iteration will arrange a KVM_SINGLESTEP exit after delivering the interrupt. Reviewed-by: David Hildenbrand Reviewed-by: Claudio Imbrenda Signed-off-by: Ilya Leoshkevich --- arch/s390/kvm/intercept.c | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) diff --git a/arch/s390/kvm/intercept.c b/arch/s390/kvm/intercept.c index e54496740859..db222c749e5e 100644 --- a/arch/s390/kvm/intercept.c +++ b/arch/s390/kvm/intercept.c @@ -583,6 +583,19 @@ static int handle_pv_notification(struct kvm_vcpu *vcpu) return handle_instruction(vcpu); } +static bool should_handle_per_ifetch(const struct kvm_vcpu *vcpu, int rc) +{ + /* Process PER, also if the instruction is processed in user space. */ + if (!(vcpu->arch.sie_block->icptstatus & 0x02)) + return false; + if (rc != 0 && rc != -EOPNOTSUPP) + return false; + if (guestdbg_sstep_enabled(vcpu) && vcpu->arch.local_int.pending_irqs) + /* __vcpu_run() will exit after delivering the interrupt. */ + return false; + return true; +} + int kvm_handle_sie_intercept(struct kvm_vcpu *vcpu) { int rc, per_rc = 0; @@ -645,9 +658,7 @@ int kvm_handle_sie_intercept(struct kvm_vcpu *vcpu) return -EOPNOTSUPP; } - /* process PER, also if the instruction is processed in user space */ - if (vcpu->arch.sie_block->icptstatus & 0x02 && - (!rc || rc == -EOPNOTSUPP)) + if (should_handle_per_ifetch(vcpu, rc)) per_rc = kvm_s390_handle_per_ifetch_icpt(vcpu); return per_rc ? per_rc : rc; }