From patchwork Wed Dec 19 19:17:52 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Mueller X-Patchwork-Id: 10737993 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 8259C161F for ; Wed, 19 Dec 2018 19:19:00 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 72C0C274D1 for ; Wed, 19 Dec 2018 19:19:00 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 66C5727528; Wed, 19 Dec 2018 19:19:00 +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 F12BA27853 for ; Wed, 19 Dec 2018 19:18:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730534AbeLSTSY (ORCPT ); Wed, 19 Dec 2018 14:18:24 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:36754 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1730488AbeLSTSW (ORCPT ); Wed, 19 Dec 2018 14:18:22 -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 wBJJ0Qtn123871 for ; Wed, 19 Dec 2018 14:18:21 -0500 Received: from e06smtp04.uk.ibm.com (e06smtp04.uk.ibm.com [195.75.94.100]) by mx0a-001b2d01.pphosted.com with ESMTP id 2pfswsf092-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Wed, 19 Dec 2018 14:18:21 -0500 Received: from localhost by e06smtp04.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 19:18:16 -0000 Received: from d06av21.portsmouth.uk.ibm.com (d06av21.portsmouth.uk.ibm.com [9.149.105.232]) by b06cxnps3075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id wBJJIFoF61735024 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Wed, 19 Dec 2018 19:18:15 GMT Received: from d06av21.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id EDE2F52051; Wed, 19 Dec 2018 19:18:14 +0000 (GMT) Received: from s38lp84.lnxne.boe (unknown [9.152.108.100]) by d06av21.portsmouth.uk.ibm.com (Postfix) with ESMTP id 934505204E; Wed, 19 Dec 2018 19:18:14 +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 11/15] KVM: s390: restore IAM in get_ipm() when IPM is clean Date: Wed, 19 Dec 2018 20:17:52 +0100 X-Mailer: git-send-email 2.13.4 In-Reply-To: <20181219191756.57973-1-mimu@linux.ibm.com> References: <20181219191756.57973-1-mimu@linux.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 18121919-0016-0000-0000-00000238D576 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18121919-0017-0000-0000-000032912D03 Message-Id: <20181219191756.57973-12-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 patch adds the parameter irq_flags and allows to restore the Interruption Alert Mask (IAM) in the GISA atomically while guaranteeing the IPM is clean. The function returns the IPM of the GISA. If the returned value is 0x00 and the IRQ_FLAG_IAM was set, the IAM has been restored. New irq flag: IRQ_FLAG_IAM: When set, the IAM is restored if no ISC bit is set in the IPM, i.e. no new airqs are pending. The test and restore operations are done atomically. Signed-off-by: Michael Mueller --- arch/s390/kvm/interrupt.c | 34 +++++++++++++++++++++++++++++----- 1 file changed, 29 insertions(+), 5 deletions(-) diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c index 1cc3ad2e6c7e..8307717e3caf 100644 --- a/arch/s390/kvm/interrupt.c +++ b/arch/s390/kvm/interrupt.c @@ -37,6 +37,7 @@ #define IRQ_FLAG_LOCAL 0x8000 /* include local interruption pending mask */ #define IRQ_FLAG_FLOATING 0x4000 /* include float interruption pending mask */ #define IRQ_FLAG_GISA 0x2000 /* include GISA interruption pending mask */ +#define IRQ_FLAG_IAM 0x0080 /* when set try to restore IAM */ #define IRQ_MASK_ALL (IRQ_FLAG_LOCAL | IRQ_FLAG_FLOATING | IRQ_FLAG_GISA) #define IRQ_MASK_NO_GISA (IRQ_MASK_ALL & ~IRQ_FLAG_GISA) @@ -253,9 +254,32 @@ static inline void set_ipm_gisc(struct kvm_s390_gisa *gisa, u32 gisc) set_bit_inv(IPM_BIT_OFFSET + gisc, (unsigned long *) gisa); } -static inline u8 get_ipm(struct kvm_s390_gisa *gisa) +static inline u8 get_ipm(struct kvm_s390_gisa *gisa, u16 irq_flags) { - return READ_ONCE(gisa->ipm); + u64 word, _word; + u8 ipm; + + if (!(irq_flags & IRQ_FLAG_IAM)) + return READ_ONCE(gisa->ipm); + + do { + word = READ_ONCE(gisa->u64.word[0]); + ipm = word >> 24; + /* If the GISA is in the alert list, return the IPM. */ + if ((u64)gisa != word >> 32) + return ipm; + /* If the IPM is dirty, return the IPM. */ + if (ipm) + return ipm; + /* + * Try to restore the IAM or loop, if the IPM is dirty + * again or the GISA has been inserted into the alert list. + */ + _word = (word & ~0xffUL) | + container_of(gisa, struct sie_page2, gisa)->kvm->arch.iam; + } while (cmpxchg(&gisa->u64.word[0], word, _word) != _word); + + return 0; } static inline void clear_ipm_gisc(struct kvm_s390_gisa *gisa, u32 gisc) @@ -277,7 +301,7 @@ static inline unsigned long pending_irqs(struct kvm_vcpu *vcpu, u16 irq_flags) if (irq_flags & IRQ_FLAG_FLOATING) pending_irqs |= vcpu->kvm->arch.float_int.pending_irqs; if (irq_flags & IRQ_FLAG_GISA) - pending_irqs |= get_ipm(vcpu->kvm->arch.gisa) << + pending_irqs |= get_ipm(vcpu->kvm->arch.gisa, irq_flags) << IRQ_PEND_IO_ISC_7; return pending_irqs; } @@ -1574,7 +1598,7 @@ static int get_top_gisa_isc(struct kvm *kvm, u64 isc_mask, u32 schid) if (!kvm->arch.gisa) goto out; - active_mask = (isc_mask & get_ipm(kvm->arch.gisa) << 24) << 32; + active_mask = (isc_mask & get_ipm(kvm->arch.gisa, IRQ_FLAG_IAM) << 24) << 32; while (active_mask) { isc = __fls(active_mask) ^ (BITS_PER_LONG - 1); if (tac_ipm_gisc(kvm->arch.gisa, isc)) @@ -2060,7 +2084,7 @@ static int get_all_floating_irqs(struct kvm *kvm, u8 __user *usrbuf, u64 len) max_irqs = len / sizeof(struct kvm_s390_irq); if (kvm->arch.gisa && - get_ipm(kvm->arch.gisa)) { + get_ipm(kvm->arch.gisa, IRQ_FLAG_IAM)) { for (i = 0; i <= MAX_ISC; i++) { if (n == max_irqs) { /* signal userspace to try again */