From patchwork Wed Apr 11 09:15:46 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Geert Uytterhoeven X-Patchwork-Id: 10335165 X-Patchwork-Delegate: geert@linux-m68k.org 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 6381F6053B for ; Wed, 11 Apr 2018 09:16:28 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 526F1287FB for ; Wed, 11 Apr 2018 09:16:28 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 46FBF287FF; Wed, 11 Apr 2018 09:16:28 +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=-7.9 required=2.0 tests=BAYES_00, MAILING_LIST_MULTI, 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 12696287FB for ; Wed, 11 Apr 2018 09:16:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752501AbeDKJP5 (ORCPT ); Wed, 11 Apr 2018 05:15:57 -0400 Received: from baptiste.telenet-ops.be ([195.130.132.51]:39602 "EHLO baptiste.telenet-ops.be" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751970AbeDKJPy (ORCPT ); Wed, 11 Apr 2018 05:15:54 -0400 Received: from ayla.of.borg ([84.194.111.163]) by baptiste.telenet-ops.be with bizsmtp id YxFs1x00T3XaVaC01xFsfz; Wed, 11 Apr 2018 11:15:52 +0200 Received: from ramsan.of.borg ([192.168.97.29] helo=ramsan) by ayla.of.borg with esmtp (Exim 4.86_2) (envelope-from ) id 1f6Br6-0002Cq-85; Wed, 11 Apr 2018 11:15:52 +0200 Received: from geert by ramsan with local (Exim 4.86_2) (envelope-from ) id 1f6Br6-0004I4-5m; Wed, 11 Apr 2018 11:15:52 +0200 From: Geert Uytterhoeven To: Baptiste Reynal , Alex Williamson Cc: Philipp Zabel , Rob Herring , Mark Rutland , kvm@vger.kernel.org, devicetree@vger.kernel.org, linux-renesas-soc@vger.kernel.org, linux-kernel@vger.kernel.org, Geert Uytterhoeven Subject: [PATCH] vfio: platform: Fix using devices in PM Domains Date: Wed, 11 Apr 2018 11:15:46 +0200 Message-Id: <1523438149-16433-1-git-send-email-geert+renesas@glider.be> X-Mailer: git-send-email 2.7.4 Sender: linux-renesas-soc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-renesas-soc@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP If a device is part of a PM Domain (e.g. power and/or clock domain), its power state is managed using Runtime PM. Without Runtime PM, the device may not be powered up, causing subtle failures, crashes, or system lock-ups when the device is accessed by the guest. Fix this by adding Runtime PM support, powering the device when the VFIO device is opened by the guest. Note that while more fine-grained power management could be implemented on the guest side, if exported, this would be inherently unsafe, as abusing it may kill the whole system. Signed-off-by: Geert Uytterhoeven --- drivers/vfio/platform/vfio_platform_common.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c index 3c13327b2777f8ec..9d46fce2446daebe 100644 --- a/drivers/vfio/platform/vfio_platform_common.c +++ b/drivers/vfio/platform/vfio_platform_common.c @@ -17,6 +17,7 @@ #include #include #include +#include #include #include #include @@ -255,6 +256,8 @@ static void vfio_platform_release(void *device_data) const char *extra_dbg = NULL; int ret; + pm_runtime_put(vdev->device); + ret = vfio_platform_call_reset(vdev, &extra_dbg); if (ret && vdev->reset_required) { dev_warn(vdev->device, "reset driver is required and reset call failed in release (%d) %s\n", @@ -297,6 +300,10 @@ static int vfio_platform_open(void *device_data) ret, extra_dbg ? extra_dbg : ""); goto err_rst; } + + ret = pm_runtime_get_sync(vdev->device); + if (ret < 0) + goto err_rst; } vdev->refcnt++; @@ -712,6 +719,7 @@ int vfio_platform_probe_common(struct vfio_platform_device *vdev, mutex_init(&vdev->igate); + pm_runtime_enable(vdev->device); return 0; put_iommu: @@ -729,6 +737,7 @@ struct vfio_platform_device *vfio_platform_remove_common(struct device *dev) vdev = vfio_del_group_dev(dev); if (vdev) { + pm_runtime_disable(vdev->device); vfio_platform_put_reset(vdev); vfio_iommu_group_put(dev->iommu_group, dev); }