From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752702AbcEWJsh (ORCPT ); Mon, 23 May 2016 05:48:37 -0400 Received: from mail-pa0-f68.google.com ([209.85.220.68]:35326 "EHLO mail-pa0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751745AbcEWJsg (ORCPT ); Mon, 23 May 2016 05:48:36 -0400 From: Peng Fan To: eric.auger@linaro.org, b.reynal@virtualopensystems.com, alex.williamson@redhat.com Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, van.freenix@gmail.com Subject: [PATCH V3] vfio: platform: support No-IOMMU mode Date: Mon, 23 May 2016 17:47:30 +0800 Message-Id: <1463996850-12559-1-git-send-email-van.freenix@gmail.com> X-Mailer: git-send-email 2.6.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The vfio No-IOMMU mode was supported by this 'commit 03a76b60f8ba2797 ("vfio: Include No-IOMMU mode")', but it only support vfio-pci. Using vfio_iommu_group_get/put, but not iommu_group_get/put, the platform devices can be exposed to userspace with CONFIG_VFIO_NOIOMMU and the "enable_unsafe_noiommu_mode" option enabled. >>From 'commit 03a76b60f8ba2797 ("vfio: Include No-IOMMU mode")', "This should make it very clear that this mode is not safe. Additionally, CAP_SYS_RAWIO privileges are necessary to work with groups and containers using this mode. Groups making use of this support are named /dev/vfio/noiommu-$GROUP and can only make use of the special VFIO_NOIOMMU_IOMMU for the container. Use of this mode, specifically binding a device without a native IOMMU group to a VFIO bus driver will taint the kernel and should therefore not be considered supported." Signed-off-by: Peng Fan Cc: Eric Auger Cc: Baptiste Reynal Cc: Alex Williamson --- V3: The platform device can be programmed to do DMA without caring out mmap + VFIO_IOMMU_MAP_DMA which are not support by noiommu. So drop the last sentence of commit log in V2, which is misleading. V2: Rename subject to support No-IOMMU Add more commit log. I wrote a simple program following this https://github.com/virtualopensystems/vfio-host-test/blob/master/src_test/vfio_device_test.c ,no dma support. The device's register can be accessed in userspace using command './vfio_dev_test 30b60000.usdhc 0 1 platform' drivers/vfio/platform/vfio_platform_common.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c index e65b142..993b2f9 100644 --- a/drivers/vfio/platform/vfio_platform_common.c +++ b/drivers/vfio/platform/vfio_platform_common.c @@ -561,7 +561,7 @@ int vfio_platform_probe_common(struct vfio_platform_device *vdev, vdev->device = dev; - group = iommu_group_get(dev); + group = vfio_iommu_group_get(dev); if (!group) { pr_err("VFIO: No IOMMU group for device %s\n", vdev->name); return -EINVAL; @@ -569,7 +569,7 @@ 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); + vfio_iommu_group_put(group, dev); return ret; } @@ -589,7 +589,7 @@ struct vfio_platform_device *vfio_platform_remove_common(struct device *dev) if (vdev) { vfio_platform_put_reset(vdev); - iommu_group_put(dev->iommu_group); + vfio_iommu_group_put(dev->iommu_group, dev); } return vdev; -- 2.6.2