From patchwork Thu Jan 12 07:19:44 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dong Jia Shi X-Patchwork-Id: 9512221 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id B9FB9601E7 for ; Thu, 12 Jan 2017 07:20:49 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id AC24D285ED for ; Thu, 12 Jan 2017 07:20:49 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A0E012861D; Thu, 12 Jan 2017 07:20:49 +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=-6.9 required=2.0 tests=BAYES_00,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 0E482285ED for ; Thu, 12 Jan 2017 07:20:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750842AbdALHUq (ORCPT ); Thu, 12 Jan 2017 02:20:46 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:60622 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750885AbdALHUn (ORCPT ); Thu, 12 Jan 2017 02:20:43 -0500 Received: from pps.filterd (m0098421.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.17/8.16.0.17) with SMTP id v0C7ItIW047430 for ; Thu, 12 Jan 2017 02:20:43 -0500 Received: from e38.co.us.ibm.com (e38.co.us.ibm.com [32.97.110.159]) by mx0a-001b2d01.pphosted.com with ESMTP id 27wyu32b70-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Thu, 12 Jan 2017 02:20:42 -0500 Received: from localhost by e38.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Thu, 12 Jan 2017 00:20:39 -0700 Received: from b03cxnp08025.gho.boulder.ibm.com (b03cxnp08025.gho.boulder.ibm.com [9.17.130.17]) by d03dlp01.boulder.ibm.com (Postfix) with ESMTP id 3F5BC1FF0021; Thu, 12 Jan 2017 00:20:17 -0700 (MST) Received: from b03ledav001.gho.boulder.ibm.com (b03ledav001.gho.boulder.ibm.com [9.17.130.232]) by b03cxnp08025.gho.boulder.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id v0C7KZN511338048; Thu, 12 Jan 2017 00:20:37 -0700 Received: from b03ledav001.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 6CE2E6E038; Thu, 12 Jan 2017 00:20:37 -0700 (MST) Received: from tuxmaker.boeblingen.de.ibm.com (unknown [9.152.85.9]) by b03ledav001.gho.boulder.ibm.com (Postfix) with ESMTP id 3643C6E045; Thu, 12 Jan 2017 00:20:35 -0700 (MST) From: Dong Jia Shi To: kvm@vger.kernel.org, linux-s390@vger.kernel.org, qemu-devel@nongnu.org Cc: bjsdjshi@linux.vnet.ibm.com, renxiaof@linux.vnet.ibm.com, cornelia.huck@de.ibm.com, borntraeger@de.ibm.com, agraf@suse.com, alex.williamson@redhat.com, pmorel@linux.vnet.ibm.com, pasic@linux.vnet.ibm.com, wkywang@linux.vnet.ibm.com Subject: [PATCH RFC v2 12/15] vfio: ccw: return I/O results asynchronously Date: Thu, 12 Jan 2017 08:19:44 +0100 X-Mailer: git-send-email 2.8.4 In-Reply-To: <20170112071947.98071-1-bjsdjshi@linux.vnet.ibm.com> References: <20170112071947.98071-1-bjsdjshi@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 X-Content-Scanned: Fidelis XPS MAILER x-cbid: 17011207-0028-0000-0000-0000066EE994 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00006418; HX=3.00000240; KW=3.00000007; PH=3.00000004; SC=3.00000199; SDB=6.00806504; UDB=6.00392482; IPR=6.00583835; BA=6.00005049; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00013900; XFM=3.00000011; UTC=2017-01-12 07:20:40 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17011207-0029-0000-0000-000032516779 Message-Id: <20170112071947.98071-13-bjsdjshi@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2017-01-12_04:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=2 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1612050000 definitions=main-1701120098 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Introduce a singlethreaded workqueue to handle the I/O interrupts. With the work added to this queue, we store the I/O results to the io_region of the subchannel, then signal the userspace program to handle the results. Signed-off-by: Dong Jia Shi --- drivers/s390/cio/vfio_ccw_drv.c | 58 ++++++++++++++++++++++--------------- drivers/s390/cio/vfio_ccw_ops.c | 3 -- drivers/s390/cio/vfio_ccw_private.h | 7 ++--- 3 files changed, 37 insertions(+), 31 deletions(-) diff --git a/drivers/s390/cio/vfio_ccw_drv.c b/drivers/s390/cio/vfio_ccw_drv.c index 595dcb4..56af313 100644 --- a/drivers/s390/cio/vfio_ccw_drv.c +++ b/drivers/s390/cio/vfio_ccw_drv.c @@ -24,6 +24,8 @@ #include "css.h" #include "vfio_ccw_private.h" +struct workqueue_struct *vfio_ccw_work_q; + /* * Helpers */ @@ -56,6 +58,7 @@ int vfio_ccw_sch_quiesce(struct subchannel *sch) spin_lock_irq(sch->lock); private->completion = NULL; + flush_workqueue(vfio_ccw_work_q); ret = cio_cancel_halt_clear(sch, &iretry); }; @@ -67,18 +70,12 @@ int vfio_ccw_sch_quiesce(struct subchannel *sch) return ret; } -static int doing_io(struct vfio_ccw_private *private, u32 intparm) -{ - return (private->intparm == intparm); -} - static int vfio_ccw_sch_io_helper(struct vfio_ccw_private *private) { struct subchannel *sch; union orb *orb; int ccode; __u8 lpm; - u32 intparm; sch = private->sch; @@ -93,7 +90,7 @@ static int vfio_ccw_sch_io_helper(struct vfio_ccw_private *private) * Initialize device status information */ sch->schib.scsw.cmd.actl |= SCSW_ACTL_START_PEND; - break; + return 0; case 1: /* Status pending */ case 2: /* Busy */ return -EBUSY; @@ -113,15 +110,26 @@ static int vfio_ccw_sch_io_helper(struct vfio_ccw_private *private) default: return ccode; } +} - intparm = (u32)(addr_t)sch; - private->intparm = 0; - wait_event(private->wait_q, doing_io(private, intparm)); +static void vfio_ccw_sch_io_todo(struct work_struct *work) +{ + struct vfio_ccw_private *private; + struct subchannel *sch; + struct irb *irb; - if (scsw_is_solicited(&private->irb.scsw)) - cp_update_scsw(&private->cp, &private->irb.scsw); + private = container_of(work, struct vfio_ccw_private, io_work); + irb = &private->irb; + sch = private->sch; - return 0; + if (scsw_is_solicited(&irb->scsw)) { + cp_update_scsw(&private->cp, &irb->scsw); + cp_free(&private->cp); + } + memcpy(private->io_region.irb_area, irb, sizeof(*irb)); + + if (private->io_trigger) + eventfd_signal(private->io_trigger, 1); } /* Deal with the ccw command request from the userspace. */ @@ -130,7 +138,6 @@ int vfio_ccw_sch_cmd_request(struct vfio_ccw_private *private) struct mdev_device *mdev = private->mdev; union orb *orb; union scsw *scsw = &private->scsw; - struct irb *irb = &private->irb; struct ccw_io_region *io_region = &private->io_region; int ret; @@ -151,12 +158,8 @@ int vfio_ccw_sch_cmd_request(struct vfio_ccw_private *private) /* Start channel program and wait for I/O interrupt. */ ret = vfio_ccw_sch_io_helper(private); - if (!ret) { - /* Get irb info and copy it to irb_area. */ - memcpy(io_region->irb_area, irb, sizeof(*irb)); - } - - cp_free(&private->cp); + if (!ret) + cp_free(&private->cp); } else if (scsw->cmd.fctl & SCSW_FCTL_HALT_FUNC) { /* XXX: Handle halt. */ ret = -EOPNOTSUPP; @@ -233,8 +236,8 @@ static void vfio_ccw_sch_irq(struct subchannel *sch) irb = this_cpu_ptr(&cio_irb); memcpy(&private->irb, irb, sizeof(*irb)); - private->intparm = (u32)(addr_t)sch; - wake_up(&private->wait_q); + + queue_work(vfio_ccw_work_q, &private->io_work); if (private->completion) complete(private->completion); @@ -273,7 +276,7 @@ static int vfio_ccw_sch_probe(struct subchannel *sch) if (ret) goto out_rm_group; - init_waitqueue_head(&private->wait_q); + INIT_WORK(&private->io_work, vfio_ccw_sch_io_todo); return 0; @@ -370,10 +373,16 @@ static int __init vfio_ccw_sch_init(void) { int ret; + vfio_ccw_work_q = create_singlethread_workqueue("vfio-ccw"); + if (!vfio_ccw_work_q) + return -ENOMEM; + isc_register(VFIO_CCW_ISC); ret = css_driver_register(&vfio_ccw_sch_driver); - if (ret) + if (ret) { isc_unregister(VFIO_CCW_ISC); + destroy_workqueue(vfio_ccw_work_q); + } return ret; } @@ -382,6 +391,7 @@ static void __exit vfio_ccw_sch_exit(void) { css_driver_unregister(&vfio_ccw_sch_driver); isc_unregister(VFIO_CCW_ISC); + destroy_workqueue(vfio_ccw_work_q); } module_init(vfio_ccw_sch_init); module_exit(vfio_ccw_sch_exit); diff --git a/drivers/s390/cio/vfio_ccw_ops.c b/drivers/s390/cio/vfio_ccw_ops.c index 3c47eb6..f1b17c4 100644 --- a/drivers/s390/cio/vfio_ccw_ops.c +++ b/drivers/s390/cio/vfio_ccw_ops.c @@ -203,9 +203,6 @@ static ssize_t vfio_ccw_mdev_write(struct mdev_device *mdev, if (region->ret_code != 0) return region->ret_code; - if (private->io_trigger) - eventfd_signal(private->io_trigger, 1); - return count; } diff --git a/drivers/s390/cio/vfio_ccw_private.h b/drivers/s390/cio/vfio_ccw_private.h index d551d98..2e5ce86 100644 --- a/drivers/s390/cio/vfio_ccw_private.h +++ b/drivers/s390/cio/vfio_ccw_private.h @@ -16,6 +16,7 @@ #include #include +#include #include #include "css.h" @@ -28,12 +29,11 @@ * @mdev: pointor to the mediated device * @nb: notifier for vfio events * @io_region: MMIO region to input/output I/O arguments/results - * @wait_q: wait for interrupt - * @intparm: record current interrupt parameter, used for wait interrupt * @cp: ccw program for the current I/O operation * @irb: irb info received from interrupt * @scsw: scsw info * @io_trigger: eventfd ctx for signaling userspace I/O results + * @io_work: work for deferral process of I/O handling */ struct vfio_ccw_private { struct subchannel *sch; @@ -42,13 +42,12 @@ struct vfio_ccw_private { struct notifier_block nb; struct ccw_io_region io_region; - wait_queue_head_t wait_q; - u32 intparm; struct ccwprogram cp; struct irb irb; union scsw scsw; struct eventfd_ctx *io_trigger; + struct work_struct io_work; } __aligned(8); extern int vfio_ccw_mdev_reg(struct subchannel *sch);