From patchwork Tue Mar 8 18:49:02 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shameerali Kolothum Thodi X-Patchwork-Id: 12774196 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 5DA46C433EF for ; Tue, 8 Mar 2022 18:51:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1349800AbiCHSwY (ORCPT ); Tue, 8 Mar 2022 13:52:24 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53208 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1349796AbiCHSwT (ORCPT ); Tue, 8 Mar 2022 13:52:19 -0500 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 57CAD53E35; Tue, 8 Mar 2022 10:51:22 -0800 (PST) Received: from fraeml742-chm.china.huawei.com (unknown [172.18.147.201]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4KCksD3Q1qz67NqQ; Wed, 9 Mar 2022 02:49:52 +0800 (CST) Received: from lhreml710-chm.china.huawei.com (10.201.108.61) by fraeml742-chm.china.huawei.com (10.206.15.223) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.21; Tue, 8 Mar 2022 19:51:20 +0100 Received: from A2006125610.china.huawei.com (10.47.82.254) by lhreml710-chm.china.huawei.com (10.201.108.61) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.21; Tue, 8 Mar 2022 18:51:12 +0000 From: Shameer Kolothum To: , , CC: , , , , , , , , , , , Subject: [PATCH v9 9/9] hisi_acc_vfio_pci: Use its own PCI reset_done error handler Date: Tue, 8 Mar 2022 18:49:02 +0000 Message-ID: <20220308184902.2242-10-shameerali.kolothum.thodi@huawei.com> X-Mailer: git-send-email 2.12.0.windows.1 In-Reply-To: <20220308184902.2242-1-shameerali.kolothum.thodi@huawei.com> References: <20220308184902.2242-1-shameerali.kolothum.thodi@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.47.82.254] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To lhreml710-chm.china.huawei.com (10.201.108.61) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Register private handler for pci_error_handlers.reset_done and update state accordingly. Reviewed-by: Jason Gunthorpe Reviewed-by: Longfang Liu Signed-off-by: Shameer Kolothum --- .../vfio/pci/hisilicon/hisi_acc_vfio_pci.c | 57 ++++++++++++++++++- .../vfio/pci/hisilicon/hisi_acc_vfio_pci.h | 4 +- 2 files changed, 57 insertions(+), 4 deletions(-) diff --git a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c index 51b814f4303b..767b5d47631a 100644 --- a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c +++ b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c @@ -626,6 +626,27 @@ static void hisi_acc_vf_disable_fds(struct hisi_acc_vf_core_device *hisi_acc_vde } } +/* + * This function is called in all state_mutex unlock cases to + * handle a 'deferred_reset' if exists. + */ +static void +hisi_acc_vf_state_mutex_unlock(struct hisi_acc_vf_core_device *hisi_acc_vdev) +{ +again: + spin_lock(&hisi_acc_vdev->reset_lock); + if (hisi_acc_vdev->deferred_reset) { + hisi_acc_vdev->deferred_reset = false; + spin_unlock(&hisi_acc_vdev->reset_lock); + hisi_acc_vdev->vf_qm_state = QM_NOT_READY; + hisi_acc_vdev->mig_state = VFIO_DEVICE_STATE_RUNNING; + hisi_acc_vf_disable_fds(hisi_acc_vdev); + goto again; + } + mutex_unlock(&hisi_acc_vdev->state_mutex); + spin_unlock(&hisi_acc_vdev->reset_lock); +} + static void hisi_acc_vf_start_device(struct hisi_acc_vf_core_device *hisi_acc_vdev) { struct hisi_qm *vf_qm = &hisi_acc_vdev->vf_qm; @@ -922,7 +943,7 @@ hisi_acc_vfio_pci_set_device_state(struct vfio_device *vdev, break; } } - mutex_unlock(&hisi_acc_vdev->state_mutex); + hisi_acc_vf_state_mutex_unlock(hisi_acc_vdev); return res; } @@ -935,10 +956,35 @@ hisi_acc_vfio_pci_get_device_state(struct vfio_device *vdev, mutex_lock(&hisi_acc_vdev->state_mutex); *curr_state = hisi_acc_vdev->mig_state; - mutex_unlock(&hisi_acc_vdev->state_mutex); + hisi_acc_vf_state_mutex_unlock(hisi_acc_vdev); return 0; } +static void hisi_acc_vf_pci_aer_reset_done(struct pci_dev *pdev) +{ + struct hisi_acc_vf_core_device *hisi_acc_vdev = dev_get_drvdata(&pdev->dev); + + if (hisi_acc_vdev->core_device.vdev.migration_flags != + VFIO_MIGRATION_STOP_COPY) + return; + + /* + * As the higher VFIO layers are holding locks across reset and using + * those same locks with the mm_lock we need to prevent ABBA deadlock + * with the state_mutex and mm_lock. + * In case the state_mutex was taken already we defer the cleanup work + * to the unlock flow of the other running context. + */ + spin_lock(&hisi_acc_vdev->reset_lock); + hisi_acc_vdev->deferred_reset = true; + if (!mutex_trylock(&hisi_acc_vdev->state_mutex)) { + spin_unlock(&hisi_acc_vdev->reset_lock); + return; + } + spin_unlock(&hisi_acc_vdev->reset_lock); + hisi_acc_vf_state_mutex_unlock(hisi_acc_vdev); +} + static int hisi_acc_vf_qm_init(struct hisi_acc_vf_core_device *hisi_acc_vdev) { struct vfio_pci_core_device *vdev = &hisi_acc_vdev->core_device; @@ -1259,12 +1305,17 @@ static const struct pci_device_id hisi_acc_vfio_pci_table[] = { MODULE_DEVICE_TABLE(pci, hisi_acc_vfio_pci_table); +static const struct pci_error_handlers hisi_acc_vf_err_handlers = { + .reset_done = hisi_acc_vf_pci_aer_reset_done, + .error_detected = vfio_pci_core_aer_err_detected, +}; + static struct pci_driver hisi_acc_vfio_pci_driver = { .name = KBUILD_MODNAME, .id_table = hisi_acc_vfio_pci_table, .probe = hisi_acc_vfio_pci_probe, .remove = hisi_acc_vfio_pci_remove, - .err_handler = &vfio_pci_core_err_handlers, + .err_handler = &hisi_acc_vf_err_handlers, }; module_pci_driver(hisi_acc_vfio_pci_driver); diff --git a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.h b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.h index 1c7d75408790..5494f4983bbe 100644 --- a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.h +++ b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.h @@ -98,6 +98,7 @@ struct hisi_acc_vf_migration_file { struct hisi_acc_vf_core_device { struct vfio_pci_core_device core_device; + u8 deferred_reset:1; /* for migration state */ struct mutex state_mutex; enum vfio_device_mig_state mig_state; @@ -107,7 +108,8 @@ struct hisi_acc_vf_core_device { struct hisi_qm vf_qm; u32 vf_qm_state; int vf_id; - + /* for reset handler */ + spinlock_t reset_lock; struct hisi_acc_vf_migration_file *resuming_migf; struct hisi_acc_vf_migration_file *saving_migf; };