From patchwork Sat May 28 22:01:16 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sinan Kaya X-Patchwork-Id: 9139605 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 C923360759 for ; Sat, 28 May 2016 22:05:12 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B97F21FF27 for ; Sat, 28 May 2016 22:05:12 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id AE09E25819; Sat, 28 May 2016 22:05:12 +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=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=unavailable version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 0C91E1FF27 for ; Sat, 28 May 2016 22:05:12 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1b6mK3-0007xr-1E; Sat, 28 May 2016 22:03:07 +0000 Received: from smtp.codeaurora.org ([198.145.29.96]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1b6mJ3-00075q-9o for linux-arm-kernel@lists.infradead.org; Sat, 28 May 2016 22:02:08 +0000 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id 5A811613B4; Sat, 28 May 2016 22:01:35 +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 0D48A613CB; Sat, 28 May 2016 22:01:32 +0000 (UTC) From: Sinan Kaya To: kvm@vger.kernel.org, timur@codeaurora.org, cov@codeaurora.org, jcm@redhat.com, eric.auger@linaro.org Subject: [PATCH V6 6/8] vfio, platform: make reset driver a requirement by default Date: Sat, 28 May 2016 18:01:16 -0400 Message-Id: <1464472878-27176-7-git-send-email-okaya@codeaurora.org> X-Mailer: git-send-email 1.8.2.1 In-Reply-To: <1464472878-27176-1-git-send-email-okaya@codeaurora.org> References: <1464472878-27176-1-git-send-email-okaya@codeaurora.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20160528_150205_582094_37DDAE0C X-CRM114-Status: GOOD ( 14.39 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Baptiste Reynal , linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, Sinan Kaya , linux-acpi@vger.kernel.org, Alex Williamson , agross@codeaurora.org, linux-arm-kernel@lists.infradead.org MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.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 | 14 +++++++++++--- drivers/vfio/platform/vfio_platform_private.h | 1 + 4 files changed, 22 insertions(+), 3 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 0ea8c26..e87ceab 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) @@ -675,7 +677,13 @@ int vfio_platform_probe_common(struct vfio_platform_device *vdev, return ret; } - vfio_platform_get_reset(vdev); + ret = vfio_platform_get_reset(vdev); + if (ret && vdev->reset_required) { + pr_err("vfio: no reset function found for device %s\n", + vdev->name); + iommu_group_put(group); + return ret; + } mutex_init(&vdev->igate); 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;