From patchwork Wed Apr 15 19:03:53 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Farman X-Patchwork-Id: 11491829 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 04CD4112C for ; Wed, 15 Apr 2020 19:08:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E9C8B20771 for ; Wed, 15 Apr 2020 19:08:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2411734AbgDOTIf (ORCPT ); Wed, 15 Apr 2020 15:08:35 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:39942 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S371248AbgDOTEJ (ORCPT ); Wed, 15 Apr 2020 15:04:09 -0400 Received: from pps.filterd (m0098414.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 03FJ2mf5033761 for ; Wed, 15 Apr 2020 15:04:07 -0400 Received: from e06smtp01.uk.ibm.com (e06smtp01.uk.ibm.com [195.75.94.97]) by mx0b-001b2d01.pphosted.com with ESMTP id 30dnmtqcvc-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Wed, 15 Apr 2020 15:04:07 -0400 Received: from localhost by e06smtp01.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, 15 Apr 2020 20:03:27 +0100 Received: from d06av22.portsmouth.uk.ibm.com (d06av22.portsmouth.uk.ibm.com [9.149.105.58]) by b06cxnps3075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 03FJ41bo57802806 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 15 Apr 2020 19:04:01 GMT Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id EC6854C058; Wed, 15 Apr 2020 19:04:00 +0000 (GMT) Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id DA8B34C04A; Wed, 15 Apr 2020 19:04:00 +0000 (GMT) Received: from tuxmaker.boeblingen.de.ibm.com (unknown [9.152.85.9]) by d06av22.portsmouth.uk.ibm.com (Postfix) with ESMTPS; Wed, 15 Apr 2020 19:04:00 +0000 (GMT) Received: by tuxmaker.boeblingen.de.ibm.com (Postfix, from userid 4958) id 737F1E027F; Wed, 15 Apr 2020 21:03:55 +0200 (CEST) From: Eric Farman To: kvm@vger.kernel.org, linux-s390@vger.kernel.org Cc: Christian Borntraeger , Janosch Frank , David Hildenbrand , Cornelia Huck , Michael Mueller , Heiko Carstens , Vasily Gorbik , Thomas Huth , Eric Farman Subject: [PATCH] KVM: s390: Fix PV check in deliverable_irqs() Date: Wed, 15 Apr 2020 21:03:53 +0200 X-Mailer: git-send-email 2.17.1 X-TM-AS-GCONF: 00 x-cbid: 20041519-4275-0000-0000-000003C0792E X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 20041519-4276-0000-0000-000038D5F14C Message-Id: <20200415190353.63625-1-farman@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.138,18.0.676 definitions=2020-04-15_06:2020-04-14,2020-04-15 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 lowpriorityscore=0 bulkscore=0 clxscore=1015 impostorscore=0 phishscore=0 spamscore=0 malwarescore=0 suspectscore=0 mlxscore=0 priorityscore=1501 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2003020000 definitions=main-2004150140 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org The diag 0x44 handler, which handles a directed yield, goes into a a codepath that does a kvm_for_each_vcpu() and ultimately deliverable_irqs(). The new check for kvm_s390_pv_cpu_is_protected() contains an assertion that the vcpu->mutex is held, which isn't going to be the case in this scenario. The result is a plethora of these messages if the lock debugging is enabled, and thus an implication that we have a problem. WARNING: CPU: 9 PID: 16167 at arch/s390/kvm/kvm-s390.h:239 deliverable_irqs+0x1c6/0x1d0 [kvm] ...snip... Call Trace: [<000003ff80429bf2>] deliverable_irqs+0x1ca/0x1d0 [kvm] ([<000003ff80429b34>] deliverable_irqs+0x10c/0x1d0 [kvm]) [<000003ff8042ba82>] kvm_s390_vcpu_has_irq+0x2a/0xa8 [kvm] [<000003ff804101e2>] kvm_arch_dy_runnable+0x22/0x38 [kvm] [<000003ff80410284>] kvm_vcpu_on_spin+0x8c/0x1d0 [kvm] [<000003ff80436888>] kvm_s390_handle_diag+0x3b0/0x768 [kvm] [<000003ff80425af4>] kvm_handle_sie_intercept+0x1cc/0xcd0 [kvm] [<000003ff80422bb0>] __vcpu_run+0x7b8/0xfd0 [kvm] [<000003ff80423de6>] kvm_arch_vcpu_ioctl_run+0xee/0x3e0 [kvm] [<000003ff8040ccd8>] kvm_vcpu_ioctl+0x2c8/0x8d0 [kvm] [<00000001504ced06>] ksys_ioctl+0xae/0xe8 [<00000001504cedaa>] __s390x_sys_ioctl+0x2a/0x38 [<0000000150cb9034>] system_call+0xd8/0x2d8 2 locks held by CPU 2/KVM/16167: #0: 00000001951980c0 (&vcpu->mutex){+.+.}, at: kvm_vcpu_ioctl+0x90/0x8d0 [kvm] #1: 000000019599c0f0 (&kvm->srcu){....}, at: __vcpu_run+0x4bc/0xfd0 [kvm] Last Breaking-Event-Address: [<000003ff80429b34>] deliverable_irqs+0x10c/0x1d0 [kvm] irq event stamp: 11967 hardirqs last enabled at (11975): [<00000001502992f2>] console_unlock+0x4ca/0x650 hardirqs last disabled at (11982): [<0000000150298ee8>] console_unlock+0xc0/0x650 softirqs last enabled at (7940): [<0000000150cba6ca>] __do_softirq+0x422/0x4d8 softirqs last disabled at (7929): [<00000001501cd688>] do_softirq_own_stack+0x70/0x80 Considering what's being done here, let's fix this by removing the mutex assertion rather than acquiring the mutex for every other vcpu. Fixes: 201ae986ead7 ("KVM: s390: protvirt: Implement interrupt injection") Signed-off-by: Eric Farman Reviewed-by: Christian Borntraeger Reviewed-by: Cornelia Huck --- arch/s390/kvm/interrupt.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c index 8191106bf7b9..bfb481134994 100644 --- a/arch/s390/kvm/interrupt.c +++ b/arch/s390/kvm/interrupt.c @@ -393,7 +393,7 @@ static unsigned long deliverable_irqs(struct kvm_vcpu *vcpu) if (psw_mchk_disabled(vcpu)) active_mask &= ~IRQ_PEND_MCHK_MASK; /* PV guest cpus can have a single interruption injected at a time. */ - if (kvm_s390_pv_cpu_is_protected(vcpu) && + if (kvm_s390_pv_cpu_get_handle(vcpu) && vcpu->arch.sie_block->iictl != IICTL_CODE_NONE) active_mask &= ~(IRQ_PEND_EXT_II_MASK | IRQ_PEND_IO_MASK |