From patchwork Mon Jun 20 15:51:17 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sinan Kaya X-Patchwork-Id: 9187877 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 0BC626075E for ; Mon, 20 Jun 2016 15:53:01 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id EDEBE26861 for ; Mon, 20 Jun 2016 15:53:00 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E21B827A98; Mon, 20 Jun 2016 15:53:00 +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=-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 468CA26861 for ; Mon, 20 Jun 2016 15:52:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932207AbcFTPwo (ORCPT ); Mon, 20 Jun 2016 11:52:44 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:35252 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752325AbcFTPvo (ORCPT ); Mon, 20 Jun 2016 11:51:44 -0400 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id AECAF6124F; Mon, 20 Jun 2016 15:51:42 +0000 (UTC) Received: from drakthul.qualcomm.com (global_nat1_iad_fw.qualcomm.com [129.46.232.65]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) (Authenticated sender: okaya@smtp.codeaurora.org) by smtp.codeaurora.org (Postfix) with ESMTPSA id ACDCC611FF; Mon, 20 Jun 2016 15:51:40 +0000 (UTC) From: Sinan Kaya To: kvm@vger.kernel.org, timur@codeaurora.org, cov@codeaurora.org, jcm@redhat.com, alex.williamson@redhat.com, eric.auger@redhat.com Cc: linux-acpi@vger.kernel.org, agross@codeaurora.org, linux-arm-msm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Sinan Kaya , Baptiste Reynal , linux-kernel@vger.kernel.org Subject: [PATCH V8 7/9] vfio, platform: make reset driver a requirement by default Date: Mon, 20 Jun 2016 11:51:17 -0400 Message-Id: <1466437879-32182-8-git-send-email-okaya@codeaurora.org> X-Mailer: git-send-email 1.8.2.1 In-Reply-To: <1466437879-32182-1-git-send-email-okaya@codeaurora.org> References: <1466437879-32182-1-git-send-email-okaya@codeaurora.org> Sender: linux-acpi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The code was allowing platform devices to be used without a supporting VFIO reset driver. The hardware can be left in some inconsistent state after a guest machine abort. The reset driver will put the hardware back to safe state and disable interrupts before returning the control back to the host machine. Adding a new reset_required kernel module option to AMBA and platform VFIO drivers with a default value of true. New requirements are: 1. A reset function needs to be implemented by the corresponding driver via DT/ACPI. 2. The reset function needs to be discovered via DT/ACPI. The probe of the driver will fail if any of the above conditions are not satisfied. Signed-off-by: Sinan Kaya --- drivers/vfio/platform/vfio_amba.c | 5 +++++ drivers/vfio/platform/vfio_platform.c | 5 +++++ drivers/vfio/platform/vfio_platform_common.c | 24 ++++++++++++++++-------- drivers/vfio/platform/vfio_platform_private.h | 1 + 4 files changed, 27 insertions(+), 8 deletions(-) diff --git a/drivers/vfio/platform/vfio_amba.c b/drivers/vfio/platform/vfio_amba.c index a66479b..7585902 100644 --- a/drivers/vfio/platform/vfio_amba.c +++ b/drivers/vfio/platform/vfio_amba.c @@ -23,6 +23,10 @@ #define DRIVER_AUTHOR "Antonios Motakis " #define DRIVER_DESC "VFIO for AMBA devices - User Level meta-driver" +static bool reset_required = true; +module_param(reset_required, bool, 0644); +MODULE_PARM_DESC(reset_required, "override reset requirement (default: 1)"); + /* probing devices from the AMBA bus */ static struct resource *get_amba_resource(struct vfio_platform_device *vdev, @@ -68,6 +72,7 @@ static int vfio_amba_probe(struct amba_device *adev, const struct amba_id *id) vdev->get_resource = get_amba_resource; vdev->get_irq = get_amba_irq; vdev->parent_module = THIS_MODULE; + vdev->reset_required = reset_required; ret = vfio_platform_probe_common(vdev, &adev->dev); if (ret) { diff --git a/drivers/vfio/platform/vfio_platform.c b/drivers/vfio/platform/vfio_platform.c index b1cc3a7..ef89146 100644 --- a/drivers/vfio/platform/vfio_platform.c +++ b/drivers/vfio/platform/vfio_platform.c @@ -23,6 +23,10 @@ #define DRIVER_AUTHOR "Antonios Motakis " #define DRIVER_DESC "VFIO for platform devices - User Level meta-driver" +static bool reset_required = true; +module_param(reset_required, bool, 0644); +MODULE_PARM_DESC(reset_required, "override reset requirement (default: 1)"); + /* probing devices from the linux platform bus */ static struct resource *get_platform_resource(struct vfio_platform_device *vdev, @@ -66,6 +70,7 @@ static int vfio_platform_probe(struct platform_device *pdev) vdev->get_resource = get_platform_resource; vdev->get_irq = get_platform_irq; vdev->parent_module = THIS_MODULE; + vdev->reset_required = reset_required; ret = vfio_platform_probe_common(vdev, &pdev->dev); if (ret) diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c index 1d771a6..b9ffed4 100644 --- a/drivers/vfio/platform/vfio_platform_common.c +++ b/drivers/vfio/platform/vfio_platform_common.c @@ -128,10 +128,10 @@ static bool vfio_platform_has_reset(struct vfio_platform_device *vdev) return vdev->of_reset ? true : false; } -static void vfio_platform_get_reset(struct vfio_platform_device *vdev) +static int vfio_platform_get_reset(struct vfio_platform_device *vdev) { if (vdev->acpihid) - return; + return vfio_platform_acpi_has_reset(vdev) ? 0 : -ENOENT; vdev->of_reset = vfio_platform_lookup_reset(vdev->compat, &vdev->reset_module); @@ -140,6 +140,8 @@ static void vfio_platform_get_reset(struct vfio_platform_device *vdev) vdev->of_reset = vfio_platform_lookup_reset(vdev->compat, &vdev->reset_module); } + + return vdev->of_reset ? 0 : -ENOENT; } static void vfio_platform_put_reset(struct vfio_platform_device *vdev) @@ -663,6 +665,13 @@ int vfio_platform_probe_common(struct vfio_platform_device *vdev, vdev->device = dev; + ret = vfio_platform_get_reset(vdev); + if (ret && vdev->reset_required) { + pr_err("vfio: no reset function found for device %s\n", + vdev->name); + return ret; + } + group = iommu_group_get(dev); if (!group) { pr_err("VFIO: No IOMMU group for device %s\n", vdev->name); @@ -670,16 +679,15 @@ int vfio_platform_probe_common(struct vfio_platform_device *vdev, } ret = vfio_add_group_dev(dev, &vfio_platform_ops, vdev); - if (ret) { - iommu_group_put(group); - return ret; - } - - vfio_platform_get_reset(vdev); + if (ret) + goto out; mutex_init(&vdev->igate); return 0; +out: + iommu_group_put(group); + return ret; } EXPORT_SYMBOL_GPL(vfio_platform_probe_common); diff --git a/drivers/vfio/platform/vfio_platform_private.h b/drivers/vfio/platform/vfio_platform_private.h index ba9e4f8..68fbc00 100644 --- a/drivers/vfio/platform/vfio_platform_private.h +++ b/drivers/vfio/platform/vfio_platform_private.h @@ -50,6 +50,7 @@ struct vfio_platform_region { }; struct vfio_platform_device { + bool reset_required; struct vfio_platform_region *regions; u32 num_regions; struct vfio_platform_irq *irqs;