From: Jason Gunthorpe <jgg@nvidia.com> To: Lu Baolu <baolu.lu@linux.intel.com> Cc: Christoph Hellwig <hch@lst.de>, Joerg Roedel <joro@8bytes.org>, David Woodhouse <dwmw2@infradead.org>, Alex Williamson <alex.williamson@redhat.com>, Kirti Wankhede <kwankhede@nvidia.com>, ashok.raj@intel.com, sanjay.k.kumar@intel.com, jacob.jun.pan@intel.com, kevin.tian@intel.com, Jean-Philippe Brucker <jean-philippe.brucker@arm.com>, 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 <jacob.jun.pan@linux.intel.com> Subject: Re: [PATCH v8 7/9] vfio/mdev: Add iommu related member in mdev_device Date: Tue, 11 May 2021 14:37:03 -0300 [thread overview] Message-ID: <20210511173703.GO1002214@nvidia.com> (raw) In-Reply-To: <2d6d3c70-0c6f-2430-3982-2705bfe9f5a6@linux.intel.com> On Tue, May 11, 2021 at 02:56:05PM +0800, Lu Baolu wrote: > > After my next series the mdev drivers will have direct access to > > the vfio_device. So an alternative to using the struct device, or > > adding 'if mdev' is to add an API to the vfio_device world to > > inject what iommu configuration is needed from that direction > > instead of trying to discover it from a struct device. > > Just want to make sure that I understand you correctly. > > We should use the existing IOMMU in-kernel APIs to connect mdev with the > iommu subsystem, so that the upper lays don't need to use something > like (if dev_is_mdev) to handle mdev differently. Do I get you > correctly? After going through all the /dev/ioasid stuff I'm pretty convinced that none of the PASID use cases for mdev should need any iommu connection from the mdev_device - this is an artifact of trying to cram the vfio container and group model into the mdev world and is not good design. The PASID interfaces for /dev/ioasid should use the 'struct pci_device' for everything and never pass in a mdev_device to the iommu layer. /dev/ioasid should be designed to support this operation and is why I strongly want to see the actual vfio_device implementation handle the connection to the iommu layer and not keep trying to hack through building what is actually a vfio_device specific connection through the type1 container code. > > 3) The vfio_bus_is_mdev() and related symbol_get() nonsense in > > drivers/vfio/vfio_iommu_type1.c has to go, for the same reasons > > it was not acceptable to do this for the interrupt side either. > > Yes. Agreed. I will look into it. This will be harder, but the same logic applies - it serves to allow controlling an ioasid without involving the vfio_device. Jason
WARNING: multiple messages have this Message-ID (diff)
From: Jason Gunthorpe <jgg@nvidia.com> To: Lu Baolu <baolu.lu@linux.intel.com> Cc: yi.y.sun@intel.com, kevin.tian@intel.com, ashok.raj@intel.com, tiwei.bie@intel.com, Jean-Philippe Brucker <jean-philippe.brucker@arm.com>, sanjay.k.kumar@intel.com, Kirti Wankhede <kwankhede@nvidia.com>, linux-kernel@vger.kernel.org, Alex Williamson <alex.williamson@redhat.com>, iommu@lists.linux-foundation.org, jacob.jun.pan@intel.com, kvm@vger.kernel.org, David Woodhouse <dwmw2@infradead.org>, Christoph Hellwig <hch@lst.de> Subject: Re: [PATCH v8 7/9] vfio/mdev: Add iommu related member in mdev_device Date: Tue, 11 May 2021 14:37:03 -0300 [thread overview] Message-ID: <20210511173703.GO1002214@nvidia.com> (raw) In-Reply-To: <2d6d3c70-0c6f-2430-3982-2705bfe9f5a6@linux.intel.com> On Tue, May 11, 2021 at 02:56:05PM +0800, Lu Baolu wrote: > > After my next series the mdev drivers will have direct access to > > the vfio_device. So an alternative to using the struct device, or > > adding 'if mdev' is to add an API to the vfio_device world to > > inject what iommu configuration is needed from that direction > > instead of trying to discover it from a struct device. > > Just want to make sure that I understand you correctly. > > We should use the existing IOMMU in-kernel APIs to connect mdev with the > iommu subsystem, so that the upper lays don't need to use something > like (if dev_is_mdev) to handle mdev differently. Do I get you > correctly? After going through all the /dev/ioasid stuff I'm pretty convinced that none of the PASID use cases for mdev should need any iommu connection from the mdev_device - this is an artifact of trying to cram the vfio container and group model into the mdev world and is not good design. The PASID interfaces for /dev/ioasid should use the 'struct pci_device' for everything and never pass in a mdev_device to the iommu layer. /dev/ioasid should be designed to support this operation and is why I strongly want to see the actual vfio_device implementation handle the connection to the iommu layer and not keep trying to hack through building what is actually a vfio_device specific connection through the type1 container code. > > 3) The vfio_bus_is_mdev() and related symbol_get() nonsense in > > drivers/vfio/vfio_iommu_type1.c has to go, for the same reasons > > it was not acceptable to do this for the interrupt side either. > > Yes. Agreed. I will look into it. This will be harder, but the same logic applies - it serves to allow controlling an ioasid without involving the vfio_device. Jason _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
next prev parent reply other threads:[~2021-05-11 17:37 UTC|newest] Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-03-25 1:30 [PATCH v8 0/9] vfio/mdev: IOMMU aware mediated device Lu Baolu 2019-03-25 1:30 ` Lu Baolu 2019-03-25 1:30 ` [PATCH v8 1/9] iommu: Add APIs for multiple domains per device Lu Baolu 2019-03-25 1:30 ` Lu Baolu 2019-03-25 1:30 ` [PATCH v8 2/9] iommu/vt-d: Make intel_iommu_enable_pasid() more generic Lu Baolu 2019-03-25 1:30 ` [PATCH v8 3/9] iommu/vt-d: Add per-device IOMMU feature ops entries Lu Baolu 2019-03-25 1:30 ` [PATCH v8 4/9] iommu/vt-d: Move common code out of iommu_attch_device() Lu Baolu 2019-03-25 1:30 ` [PATCH v8 5/9] iommu/vt-d: Aux-domain specific domain attach/detach Lu Baolu 2019-03-25 1:30 ` [PATCH v8 6/9] iommu/vt-d: Return ID associated with an auxiliary domain Lu Baolu 2019-03-25 1:30 ` Lu Baolu 2019-03-25 1:30 ` [PATCH v8 7/9] vfio/mdev: Add iommu related member in mdev_device Lu Baolu 2019-03-26 9:32 ` Kirti Wankhede 2019-03-27 14:17 ` Parav Pandit 2019-03-27 18:16 ` Alex Williamson 2019-03-27 18:16 ` Alex Williamson 2019-03-26 17:42 ` Alex Williamson 2021-04-06 20:00 ` Jason Gunthorpe 2021-04-06 20:00 ` Jason Gunthorpe 2021-04-07 1:58 ` Lu Baolu 2021-04-07 1:58 ` Lu Baolu 2021-04-07 11:34 ` Jason Gunthorpe 2021-04-07 11:34 ` Jason Gunthorpe 2021-05-11 6:56 ` Lu Baolu 2021-05-11 6:56 ` Lu Baolu 2021-05-11 17:37 ` Jason Gunthorpe [this message] 2021-05-11 17:37 ` Jason Gunthorpe 2021-05-12 7:46 ` Tian, Kevin 2021-05-12 7:46 ` Tian, Kevin 2021-05-17 14:03 ` Jason Gunthorpe 2021-05-17 14:03 ` Jason Gunthorpe 2019-03-25 1:30 ` [PATCH v8 8/9] vfio/type1: Add domain at(de)taching group helpers Lu Baolu 2019-03-26 17:42 ` Alex Williamson 2019-03-26 17:42 ` Alex Williamson 2019-03-25 1:30 ` [PATCH v8 9/9] vfio/type1: Handle different mdev isolation type Lu Baolu 2019-03-26 9:33 ` Kirti Wankhede 2019-03-26 17:42 ` Alex Williamson 2019-04-11 15:19 ` [PATCH v8 0/9] vfio/mdev: IOMMU aware mediated device Joerg Roedel 2019-04-11 15:19 ` Joerg Roedel 2019-04-12 1:36 ` Lu Baolu 2019-04-12 1:36 ` Lu Baolu
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=20210511173703.GO1002214@nvidia.com \ --to=jgg@nvidia.com \ --cc=alex.williamson@redhat.com \ --cc=ashok.raj@intel.com \ --cc=baolu.lu@linux.intel.com \ --cc=dwmw2@infradead.org \ --cc=hch@lst.de \ --cc=iommu@lists.linux-foundation.org \ --cc=jacob.jun.pan@intel.com \ --cc=jacob.jun.pan@linux.intel.com \ --cc=jean-philippe.brucker@arm.com \ --cc=joro@8bytes.org \ --cc=kevin.tian@intel.com \ --cc=kvm@vger.kernel.org \ --cc=kwankhede@nvidia.com \ --cc=linux-kernel@vger.kernel.org \ --cc=peterx@redhat.com \ --cc=sanjay.k.kumar@intel.com \ --cc=tiwei.bie@intel.com \ --cc=xin.zeng@intel.com \ --cc=yi.l.liu@intel.com \ --cc=yi.y.sun@intel.com \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.