From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753211AbcFLJCN (ORCPT ); Sun, 12 Jun 2016 05:02:13 -0400 Received: from mail-pf0-f194.google.com ([209.85.192.194]:34845 "EHLO mail-pf0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751381AbcFLJCL (ORCPT ); Sun, 12 Jun 2016 05:02:11 -0400 Date: Sun, 12 Jun 2016 17:02:00 +0800 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 Subject: Re: [PATCH V3] vfio: platform: support No-IOMMU mode Message-ID: <20160612090158.GA27614@linux-7smt.suse> References: <1463996850-12559-1-git-send-email-van.freenix@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1463996850-12559-1-git-send-email-van.freenix@gmail.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, Kindly ping.. Any comments on V3? Thanks, Peng. On Mon, May 23, 2016 at 05:47:30PM +0800, Peng Fan wrote: >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 >