From mboxrd@z Thu Jan 1 00:00:00 1970 From: Neo Jia Subject: Re: [PATCH v7 9/9] vfio/type1: Handle different mdev isolation type Date: Fri, 8 Mar 2019 10:03:18 -0800 Message-ID: <20190308180317.GA30821@nvidia.com> References: <20190222021927.13132-1-baolu.lu@linux.intel.com> <20190222021927.13132-10-baolu.lu@linux.intel.com> <20190307084453.GA9288@nvidia.com> <20190307165623.1834cc93@w520.home> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Return-path: Content-Disposition: inline In-Reply-To: <20190307165623.1834cc93@w520.home> Sender: linux-kernel-owner@vger.kernel.org To: Alex Williamson Cc: Lu Baolu , Joerg Roedel , David Woodhouse , Kirti Wankhede , ashok.raj@intel.com, sanjay.k.kumar@intel.com, jacob.jun.pan@intel.com, kevin.tian@intel.com, Jean-Philippe Brucker , yi.l.liu@intel.com, yi.y.sun@intel.com, peterx@redhat.com, tiwei.bie@intel.com, xin.zeng@intel.com, iommu@lists.linux-foundation.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Jacob Pan List-Id: iommu@lists.linux-foundation.org On Thu, Mar 07, 2019 at 04:56:23PM -0700, Alex Williamson wrote: > On Thu, 7 Mar 2019 00:44:54 -0800 > Neo Jia wrote: > > > On Fri, Feb 22, 2019 at 10:19:27AM +0800, Lu Baolu wrote: > > > This adds the support to determine the isolation type > > > of a mediated device group by checking whether it has > > > an iommu device. If an iommu device exists, an iommu > > > domain will be allocated and then attached to the iommu > > > device. Otherwise, keep the same behavior as it is. > > > > > > Cc: Ashok Raj > > > Cc: Jacob Pan > > > Cc: Kevin Tian > > > Signed-off-by: Sanjay Kumar > > > Signed-off-by: Liu Yi L > > > Signed-off-by: Lu Baolu > > > Reviewed-by: Jean-Philippe Brucker > > > --- > > > drivers/vfio/vfio_iommu_type1.c | 48 ++++++++++++++++++++++++++++----- > > > 1 file changed, 41 insertions(+), 7 deletions(-) > > > > > > diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c > > > index ccc4165474aa..f1392c582a3c 100644 > > > --- a/drivers/vfio/vfio_iommu_type1.c > > > +++ b/drivers/vfio/vfio_iommu_type1.c > > > @@ -1368,13 +1368,40 @@ static void vfio_iommu_detach_group(struct vfio_domain *domain, > > > iommu_detach_group(domain->domain, group->iommu_group); > > > } > > > > > > > Hi Baolu, > > > > To allow IOMMU-awared mdev, I think you need to modify the > > vfio_iommu_type1_pin_pages and vfio_iommu_type1_unpin_pages to remove the > > iommu->external_domain check. > > > > Could you please include that in your patch? If not, I can send out a separate > > patch to address that issue. > > I figured it was intentional that an IOMMU backed mdev would not use > the pin/unpin interface and therefore the exiting -EINVAL returns would > be correct. Can you elaborate on the use case for still requiring the > mdev pin/unpin interface for these devices? Thanks, Sure. We are using this api to fetch a pfn of a guest physical address so we can access it for PV. Thanks, Neo > > Alex