From nobody Mon Apr 6 11:52:08 2026 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 092C3C433FE for ; Fri, 30 Sep 2022 00:09:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229772AbiI3AJu (ORCPT ); Thu, 29 Sep 2022 20:09:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37672 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229524AbiI3AJp (ORCPT ); Thu, 29 Sep 2022 20:09:45 -0400 Received: from APC01-SG2-obe.outbound.protection.outlook.com (mail-sgaapc01on2074.outbound.protection.outlook.com [40.107.215.74]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 04F1217AB5 for ; Thu, 29 Sep 2022 17:09:43 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=UdSCBeB/J1rUKsdm6/jLjBW3cA19bdnMRC9+BH65ZmUBhUXs9xODPzJ6Tf7bUK4e2vxTFdSBWYbvhW7HPYy/MRzqTE+JdbsUINfkXU6KUmotAGk6ZTKvW+C6N20Ob4iZjU0RuC1hT4Js5jp7ACuXdiztnxFu8LXgzTNjsitu5L0tosO1snVj4gztubChKM/t1/V6K2lkRpb2CljGc/OZwCdcU2cbzQACpZ4Lj1zuy5sGMKsXmgtfjf6mazwe3Q72hJRjjF5ByiRjmXhBvQEJdNawHmIOBJeaoGtB1MCfAR5TGrpIB0MEQogU3ah81juwSmGasC783Qfri8x4t9rs7g== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=myne8LuqDdibLpSF7gbKSnRqLGSWpOYrW3tAokIRvDM=; b=HKlG4gr0td8Q/JTXiIptAoLqDcTiRob9leqvpV1rps/VIrOa44uI/NKTJQf4ehB815ceA7wq3Hcq6myFmFZNIJ9CxWgwfKUqanCc6AYLzmSma5eVVoP1Yy1MC50LeiuJvl2vVHrmdFXxPWp1xXfsv1SmEUPnfD0WlWFnCwXOIjTyq/lsYUsKNTerCrO0Z7jCnjy0p44Exef8O1875Emd2f5YUNdKnsIFcU3Pe6tPm9Q4Tg5EkWgj5QUEV/kKIfMvBOIHm/Ok1VaU18F0qc6ossrBdvTYTgYFLt9nqvgbHcV7p6QmD5lHZRmga/NEbGdNO3cOlSrRzddFcssNZSnrjg== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=jaguarmicro.com; dmarc=pass action=none header.from=jaguarmicro.com; dkim=pass header.d=jaguarmicro.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=jaguarmicro.com; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=myne8LuqDdibLpSF7gbKSnRqLGSWpOYrW3tAokIRvDM=; b=QMN5gkadXio7a4q26G/GbEnI7ZdxCJ4SEHKwMGHUzuETB6jlUiQ97Y2d+SNRNxGiPR2A04mnfLgK16LGiD18pFmVDLYLodNkIjEmcXehJoLeQS2e/wQ005zA6MryxPaWbt+zOf7O56/n/tyTS01DurK2wGyq+yQWuYTp/BtjxBOndxedIvpbdoVIyuO3QoTitHzRx42pldDZiSfBz34Dp5tuGIdWh62QdggbfKSm0X9NoanxNN3axsWyXq5TsdK4K0NrBAu7GZXV+J2bM410HyD34bhTPBwBf/LBzHFpWBr49uKDNYLs96xqWUJDL/3DjXdDvbMeyu0Ce9IMsPnZOw== Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=jaguarmicro.com; Received: from TY2PR06MB3424.apcprd06.prod.outlook.com (2603:1096:404:104::19) by SEZPR06MB5624.apcprd06.prod.outlook.com (2603:1096:101:c8::14) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.5676.23; Fri, 30 Sep 2022 00:09:38 +0000 Received: from TY2PR06MB3424.apcprd06.prod.outlook.com ([fe80::aa83:33dc:435c:cb5d]) by TY2PR06MB3424.apcprd06.prod.outlook.com ([fe80::aa83:33dc:435c:cb5d%6]) with mapi id 15.20.5654.026; Fri, 30 Sep 2022 00:09:38 +0000 From: Angus Chen To: jasowang@redhat.com, mst@redhat.com Cc: virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org, Angus Chen Subject: [PATCH v3] virtio_pci: avoid to request intx irq if pin is zero Date: Fri, 30 Sep 2022 08:09:15 +0800 Message-Id: <20220930000915.548-1-angus.chen@jaguarmicro.com> X-Mailer: git-send-email 2.33.0.windows.1 Content-Transfer-Encoding: quoted-printable X-ClientProxiedBy: SI2PR01CA0010.apcprd01.prod.exchangelabs.com (2603:1096:4:191::12) To TY2PR06MB3424.apcprd06.prod.outlook.com (2603:1096:404:104::19) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: TY2PR06MB3424:EE_|SEZPR06MB5624:EE_ X-MS-Office365-Filtering-Correlation-Id: bd942ef5-a3f7-47d9-952d-08daa2781028 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:TY2PR06MB3424.apcprd06.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230022)(366004)(396003)(346002)(136003)(39840400004)(376002)(451199015)(26005)(6512007)(186003)(5660300002)(1076003)(83380400001)(2616005)(44832011)(66476007)(66556008)(66946007)(6486002)(4326008)(2906002)(316002)(8676002)(478600001)(86362001)(107886003)(6666004)(38100700002)(8936002)(38350700002)(52116002)(36756003)(6506007)(41300700001);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?fh2Vqyt+1TPvogjABGg3Irq3676zg1UUXwiln7CY3vj/CuLSGMntv7JB4D1z?= =?us-ascii?Q?Pb7bzr6Ds2RqnBzx1tGsjkxMvq5dme187Xk0A93p0HmXiPwtIF69a0tnLEsU?= =?us-ascii?Q?lVtTYtVBMWtUll78K4mCMSGBRW6DyqclCYtd6Swr1uQ3QwFtnzBaD+pfh4d8?= =?us-ascii?Q?v2mMoAZ3Wk0vyiU0DoLvHS6tFIDJEj0g4vscuI4YWfAgvegDpytF2i86FN+Z?= =?us-ascii?Q?8cA3Gv+OMRQkeXMlmOV3qlGY58ePfopE2GzTJw7sQPJB9fqtzW4Is0yM17ly?= =?us-ascii?Q?RqmgKsXk8CF6vJrM8cEvpL9K3KTPGU/SIAwNrMTc6zdvZ4Yk2iS94GzinYyW?= =?us-ascii?Q?PlUKMWBM7yElCM8wFjCqCc3rE6oU7Yypy/HsgZaNLsH92TKp5icyjqwud+cM?= =?us-ascii?Q?tMNM/sq+OFaWNREdDX/XGSRURTyB1x7+FPFfm0XgETdWK35wRyqrNDIgjn8Q?= =?us-ascii?Q?BRQd+OTdFaBYQyI5+AoVaqqFLD5kfCsoe7WWleSpAVgeZ3OwbQhAyG9aBBjn?= =?us-ascii?Q?AptfCcebtQUM7oRh6qKtKHRqM4rz8o1Y8O463ZqT9diSAzK6scnVaMkuzneY?= =?us-ascii?Q?DQKahT9DrtTD8r2lG/WFPp+rTDsYHLcifNXtTD5aZtS6X/6iqwFFpGRtnR0B?= =?us-ascii?Q?CnrHeEaqG3OeDXGnyWWm5nBpdeaG+c72bE2eknWOIET5x/OFavDfTn6eJGrz?= =?us-ascii?Q?ol/i1rJehuRn4vOuu0nG3t1pJ5/UeNShJy9nxDcQZQWJjpcy/+Lu+N/wN0Nn?= =?us-ascii?Q?+U8Fln8mJLvJs+KevnldBxYEI+hrC/UOn0v3SEnSALe/znXi3xeAHYMKmZas?= =?us-ascii?Q?Iw8iHocln7ZCb0ezOvuZ6Z64PJtlNBKn9lLgaswNRMG5EgpnqA9EFf9gDDF8?= =?us-ascii?Q?Zd0dLxyj8dBmCJic272xV0/4azZn+S7qZQAktGj6mHMv0GQ2paDKLok6X9C7?= =?us-ascii?Q?nOXxrMb6APJzpS/Z2mu+MwrsujJ1OypEageXCsXcQx6po3EYoAdrhkyvaWqL?= =?us-ascii?Q?Q0VhUJqq9qb/NB05hBwTbOmZye71I2aSxuWS5kcTV72D8Yvc/RxTZufasKkN?= =?us-ascii?Q?iTQIbuDVeUaGWkk5xS2fW0QQ6Gav1igwlgkexvQ5OtaC2CaAx135+T6HQHLA?= =?us-ascii?Q?qprBDRAGjoGgZ0p3Vl25GgsmWsyBGnt6Nm+p4w6NZT+yOoDCwAS9THJpd5k+?= =?us-ascii?Q?bZHi55FOmwmfv/4F9nQJhJ1pOKgMtbiZuq+PEAT68a+knyA3jtzzcvH3Ziuz?= =?us-ascii?Q?8NJLog+xAdNbX32s1bFq64baqf3PTMTiDVI0rXBzgTc/wybldVhSsSYoc+r1?= =?us-ascii?Q?0/XFGLJNExodPJ7/dxdsFGoln78SvydSF+uurDldkn2/XMj/rLHrtbvs0Lpp?= =?us-ascii?Q?lNE51r6GuZ8sP28SXFbHuSFhwOP2WXK4fwgSCjidRIbI2tzlawj5SPaEeHeh?= =?us-ascii?Q?K8LrZR4TnlSE57uzi9UvRykrCVRLRIJp7wu6X0/tM5WgIZMPmR0FuKyZhCvS?= =?us-ascii?Q?Hhfz4jtCLpCGJZKtEg1kYTJdsFrBmiZ4JknOd6p1GMUmQwuW/FS+d3SHnwtc?= =?us-ascii?Q?cic3VO+uK03Oy10lFNFIoDLX3wR4Pmlp6VBF7Nn+OVjTxtJTiUmrx1vhqIJe?= =?us-ascii?Q?UA=3D=3D?= X-OriginatorOrg: jaguarmicro.com X-MS-Exchange-CrossTenant-Network-Message-Id: bd942ef5-a3f7-47d9-952d-08daa2781028 X-MS-Exchange-CrossTenant-AuthSource: TY2PR06MB3424.apcprd06.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 30 Sep 2022 00:09:37.9404 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 1e45a5c2-d3e1-46b3-a0e6-c5ebf6d8ba7b X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: i74g0Lqc74UW5PYW+NPk+3gqIHbwn38qw+WQUJ8LD/u8aW1RMP0IYDwoL2AIlH1T7bBj1q1EXRKLAgvKgn/LXGeyzclMQoNalQM36kDtldY= X-MS-Exchange-Transport-CrossTenantHeadersStamped: SEZPR06MB5624 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" The background is that we use dpu in cloud computing,the arch is x86,80 cores.We will have a lots of virtio devices,like 512 or more. When we probe about 200 virtio_blk devices,it will fail and the stack is print as follows: [25338.485128] virtio-pci 0000:b3:00.0: virtio_pci: leaving for legacy driv= er [25338.496174] genirq: Flags mismatch irq 0. 00000080 (virtio418) vs. 00015= a00 (timer) [25338.503822] CPU: 20 PID: 5431 Comm: kworker/20:0 Kdump: loaded Tainted: = G OE --------- - - 4.18.0-305.30.1.el8.x86_64 [25338.516403] Hardware name: Inspur NF5280M5/YZMB-00882-10E, BIOS 4.1.21 0= 8/25/2021 [25338.523881] Workqueue: events work_for_cpu_fn [25338.528235] Call Trace: [25338.530687] dump_stack+0x5c/0x80 [25338.534000] __setup_irq.cold.53+0x7c/0xd3 [25338.538098] request_threaded_irq+0xf5/0x160 [25338.542371] vp_find_vqs+0xc7/0x190 [25338.545866] init_vq+0x17c/0x2e0 [virtio_blk] [25338.550223] ? ncpus_cmp_func+0x10/0x10 [25338.554061] virtblk_probe+0xe6/0x8a0 [virtio_blk] [25338.558846] virtio_dev_probe+0x158/0x1f0 [25338.562861] really_probe+0x255/0x4a0 [25338.566524] ? __driver_attach_async_helper+0x90/0x90 [25338.571567] driver_probe_device+0x49/0xc0 [25338.575660] bus_for_each_drv+0x79/0xc0 [25338.579499] __device_attach+0xdc/0x160 [25338.583337] bus_probe_device+0x9d/0xb0 [25338.587167] device_add+0x418/0x780 [25338.590654] register_virtio_device+0x9e/0xe0 [25338.595011] virtio_pci_probe+0xb3/0x140 [25338.598941] local_pci_probe+0x41/0x90 [25338.602689] work_for_cpu_fn+0x16/0x20 [25338.606443] process_one_work+0x1a7/0x360 [25338.610456] ? create_worker+0x1a0/0x1a0 [25338.614381] worker_thread+0x1cf/0x390 [25338.618132] ? create_worker+0x1a0/0x1a0 [25338.622051] kthread+0x116/0x130 [25338.625283] ? kthread_flush_work_fn+0x10/0x10 [25338.629731] ret_from_fork+0x1f/0x40 [25338.633395] virtio_blk: probe of virtio418 failed with error -16 The log : "genirq: Flags mismatch irq 0. 00000080 (virtio418) vs. 00015a00 (timer)" was print because of the irq 0 is used by timer exclusive,and when vp_find_vqs call vp_find_vqs_msix and return false twice for whatever reason,then it will call vp_find_vqs_intx for the last try. Because vp_dev->pci_dev->irq is zero,so it will be request irq 0 with flag IRQF_SHARED,we will get a backtrace like above. According to PCI spec about "Interrupt Pin" Register (Offset 3Dh): "The Interrupt Pin register is a read-only register that identifies the legacy interrupt Message(s) the Function uses. Valid values are 01h, 02h, 03h, and 04h that map to legacy interrupt Messages for INTA, INTB, INTC, and INTD respectively. A value of 00h indicates that the Function uses no legacy interrupt Message(s)." So if vp_dev->pci_dev->pin is zero, we should not request legacy interrupt. Signed-off-by: Angus Chen Suggested-by: Michael S. Tsirkin --- v3: - add quotes of PCI spec - Move the judgment from vp_find_vqs_intx to vp_find_vqs v2: - Decide whether to request an intx interrupt by pin instead of irq - suggested by mst v1:https://lore.kernel.org/virtualization/20220928000228-mutt-send-email-ms= t@kernel.org/T/#u drivers/virtio/virtio_pci_common.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/virtio/virtio_pci_common.c b/drivers/virtio/virtio_pci= _common.c index ad258a9d3b9f..44a839127f2b 100644 --- a/drivers/virtio/virtio_pci_common.c +++ b/drivers/virtio/virtio_pci_common.c @@ -409,6 +409,9 @@ int vp_find_vqs(struct virtio_device *vdev, unsigned in= t nvqs, err =3D vp_find_vqs_msix(vdev, nvqs, vqs, callbacks, names, false, ctx, d= esc); if (!err) return 0; + /* Is there an interrupt pin? If not give up. */ + if (!(to_vp_device(vdev)->pci_dev->pin)) + return err; /* Finally fall back to regular interrupts. */ return vp_find_vqs_intx(vdev, nvqs, vqs, callbacks, names, ctx); } --=20 2.17.1