Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933861AbcJUOgG (ORCPT ); Fri, 21 Oct 2016 10:36:06 -0400 Received: from mx1.redhat.com ([209.132.183.28]:56612 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932814AbcJUOgE (ORCPT ); Fri, 21 Oct 2016 10:36:04 -0400 Date: Fri, 21 Oct 2016 08:36:02 -0600 From: Alex Williamson To: Jike Song Cc: Kirti Wankhede , pbonzini@redhat.com, kraxel@redhat.com, cjia@nvidia.com, qemu-devel@nongnu.org, kvm@vger.kernel.org, kevin.tian@intel.com, bjsdjshi@linux.vnet.ibm.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH v9 04/12] vfio iommu: Add support for mediated devices Message-ID: <20161021083602.2b05ecac@t450s.home> In-Reply-To: <5809C873.1040703@intel.com> References: <1476739332-4911-1-git-send-email-kwankhede@nvidia.com> <1476739332-4911-5-git-send-email-kwankhede@nvidia.com> <5809C873.1040703@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.26]); Fri, 21 Oct 2016 14:36:03 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1939 Lines: 54 On Fri, 21 Oct 2016 15:49:07 +0800 Jike Song wrote: > On 10/18/2016 05:22 AM, Kirti Wankhede wrote: > > diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c > > index 2ba19424e4a1..5d67058a611d 100644 > > --- a/drivers/vfio/vfio_iommu_type1.c > > +++ b/drivers/vfio/vfio_iommu_type1.c > [snip] > > static int vfio_iommu_type1_attach_group(void *iommu_data, > > struct iommu_group *iommu_group) > > { > > struct vfio_iommu *iommu = iommu_data; > > - struct vfio_group *group, *g; > > + struct vfio_group *group; > > struct vfio_domain *domain, *d; > > struct bus_type *bus = NULL; > > int ret; > > @@ -746,10 +1136,14 @@ static int vfio_iommu_type1_attach_group(void *iommu_data, > > mutex_lock(&iommu->lock); > > > > list_for_each_entry(d, &iommu->domain_list, next) { > > - list_for_each_entry(g, &d->group_list, next) { > > - if (g->iommu_group != iommu_group) > > - continue; > > + if (find_iommu_group(d, iommu_group)) { > > + mutex_unlock(&iommu->lock); > > + return -EINVAL; > > + } > > + } > > > > + if (iommu->local_domain) { > > + if (find_iommu_group(iommu->local_domain, iommu_group)) { > > mutex_unlock(&iommu->lock); > > return -EINVAL; > > } > > @@ -769,6 +1163,30 @@ static int vfio_iommu_type1_attach_group(void *iommu_data, > > if (ret) > > goto out_free; > > > > + if (IS_ENABLED(CONFIG_VFIO_MDEV) && !iommu_present(bus) && > > + (bus == &mdev_bus_type)) { > > Hi Kirti, > > By refering mdev_bus_type directly you are making vfio_iommu_type1.ko depends > on mdev.ko, but in Kconfig doesn't guarantee the dependency. For example, > if CONFIG_VFIO_IOMMU_TYPE1=y and CONFIG_VFIO_MDEV=m, the building will fail. Good point, Jike. I don't think we want to make existing vfio modules dependent on mdev modules. I wonder if we can lookup the mdev_bus_type symbol w/o triggering the module load. Thanks, Alex