From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965316AbeE2RPg (ORCPT ); Tue, 29 May 2018 13:15:36 -0400 Received: from michel.telenet-ops.be ([195.130.137.88]:46462 "EHLO michel.telenet-ops.be" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S936855AbeE2RPa (ORCPT ); Tue, 29 May 2018 13:15:30 -0400 From: Geert Uytterhoeven To: Eric Auger , Alex Williamson Cc: kvm@vger.kernel.org, linux-renesas-soc@vger.kernel.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, Geert Uytterhoeven Subject: [PATCH v4] vfio: platform: Fix using devices in PM Domains Date: Tue, 29 May 2018 19:15:28 +0200 Message-Id: <1527614128-30196-1-git-send-email-geert+renesas@glider.be> X-Mailer: git-send-email 2.7.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 or clocked, 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. Signed-off-by: Geert Uytterhoeven Reviewed-by: Simon Horman --- Against linux-vfio/next v4: - Keep device powered while issuing reset, v3: - Drop controversial note about unsafeness of exporting fine-grained power management from host to guest, v2: - Improve wording, - Add Reviewed-by. --- drivers/vfio/platform/vfio_platform_common.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c index b60bb5326668498c..c0cd824be2b767be 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 @@ -239,6 +240,7 @@ static void vfio_platform_release(void *device_data) ret, extra_dbg ? extra_dbg : ""); WARN_ON(1); } + pm_runtime_put(vdev->device); vfio_platform_regions_cleanup(vdev); vfio_platform_irq_cleanup(vdev); } @@ -269,6 +271,10 @@ static int vfio_platform_open(void *device_data) if (ret) goto err_irq; + ret = pm_runtime_get_sync(vdev->device); + if (ret < 0) + goto err_pm; + 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 open (%d) %s\n", @@ -283,6 +289,8 @@ static int vfio_platform_open(void *device_data) return 0; err_rst: + pm_runtime_put(vdev->device); +err_pm: vfio_platform_irq_cleanup(vdev); err_irq: vfio_platform_regions_cleanup(vdev); @@ -690,6 +698,7 @@ int vfio_platform_probe_common(struct vfio_platform_device *vdev, mutex_init(&vdev->igate); + pm_runtime_enable(vdev->device); return 0; put_iommu: @@ -707,6 +716,7 @@ 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); } -- 2.7.4