From: Jason Gunthorpe <jgg@nvidia.com>
To: "Liu, Yi L" <yi.l.liu@intel.com>
Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>,
"alex.williamson@redhat.com" <alex.williamson@redhat.com>,
"eric.auger@redhat.com" <eric.auger@redhat.com>,
"baolu.lu@linux.intel.com" <baolu.lu@linux.intel.com>,
"joro@8bytes.org" <joro@8bytes.org>,
"Tian, Kevin" <kevin.tian@intel.com>,
"Raj, Ashok" <ashok.raj@intel.com>,
"Tian, Jun J" <jun.j.tian@intel.com>,
"Sun, Yi Y" <yi.y.sun@intel.com>,
"jean-philippe@linaro.org" <jean-philippe@linaro.org>,
"peterx@redhat.com" <peterx@redhat.com>,
"jasowang@redhat.com" <jasowang@redhat.com>,
"Wu, Hao" <hao.wu@intel.com>,
"stefanha@gmail.com" <stefanha@gmail.com>,
"iommu@lists.linux-foundation.org"
<iommu@lists.linux-foundation.org>,
"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
"Zhu, Lingshan" <lingshan.zhu@intel.com>,
"vivek.gautam@arm.com" <vivek.gautam@arm.com>
Subject: Re: [Patch v8 04/10] vfio/type1: Support binding guest page tables to PASID
Date: Thu, 4 Mar 2021 08:52:01 -0400 [thread overview]
Message-ID: <20210304125201.GA4247@nvidia.com> (raw)
In-Reply-To: <BN6PR11MB4068D05B70842124234A7AF4C3979@BN6PR11MB4068.namprd11.prod.outlook.com>
On Thu, Mar 04, 2021 at 07:20:22AM +0000, Liu, Yi L wrote:
> > > However, IOMMU is a system device which has little value to be exposed
> > to
> > > the userspace. Not to mention the device-IOMMU affinity/topology. VFIO
> > > nicely abstracts IOMMU from the userspace, why do we want to reverse
> > that?
> >
> > The other patch was talking about a /dev/ioasid - why can't this stuff
> > be run over that?
>
> The stuff in this patch are actually iommu domain operations, which are
> finally supported by iommu domain ops. While /dev/ioasid in another patch
> is created for IOASID allocation/free to fit the PASID allocation requirement
> from both vSVA and vDPA. It has no idea about iommu domain and neither the
> device information. Without such info, /dev/ioasid is unable to run this
> stuff.
Why can't it know? My point was that VFIO should interact with
/dev/ioasid to exchange the information both sides need and once
exchanged the control over IOMMU should be done through /dev/ioasid,
not inside VFIO.
Jason
WARNING: multiple messages have this Message-ID (diff)
From: Jason Gunthorpe <jgg@nvidia.com>
To: "Liu, Yi L" <yi.l.liu@intel.com>
Cc: "jean-philippe@linaro.org" <jean-philippe@linaro.org>,
"Tian, Kevin" <kevin.tian@intel.com>,
"Raj, Ashok" <ashok.raj@intel.com>,
"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
"vivek.gautam@arm.com" <vivek.gautam@arm.com>,
"jasowang@redhat.com" <jasowang@redhat.com>,
"stefanha@gmail.com" <stefanha@gmail.com>,
"Sun, Yi Y" <yi.y.sun@intel.com>,
"alex.williamson@redhat.com" <alex.williamson@redhat.com>,
"iommu@lists.linux-foundation.org"
<iommu@lists.linux-foundation.org>,
"Zhu, Lingshan" <lingshan.zhu@intel.com>,
"Wu, Hao" <hao.wu@intel.com>,
"Tian, Jun J" <jun.j.tian@intel.com>
Subject: Re: [Patch v8 04/10] vfio/type1: Support binding guest page tables to PASID
Date: Thu, 4 Mar 2021 08:52:01 -0400 [thread overview]
Message-ID: <20210304125201.GA4247@nvidia.com> (raw)
In-Reply-To: <BN6PR11MB4068D05B70842124234A7AF4C3979@BN6PR11MB4068.namprd11.prod.outlook.com>
On Thu, Mar 04, 2021 at 07:20:22AM +0000, Liu, Yi L wrote:
> > > However, IOMMU is a system device which has little value to be exposed
> > to
> > > the userspace. Not to mention the device-IOMMU affinity/topology. VFIO
> > > nicely abstracts IOMMU from the userspace, why do we want to reverse
> > that?
> >
> > The other patch was talking about a /dev/ioasid - why can't this stuff
> > be run over that?
>
> The stuff in this patch are actually iommu domain operations, which are
> finally supported by iommu domain ops. While /dev/ioasid in another patch
> is created for IOASID allocation/free to fit the PASID allocation requirement
> from both vSVA and vDPA. It has no idea about iommu domain and neither the
> device information. Without such info, /dev/ioasid is unable to run this
> stuff.
Why can't it know? My point was that VFIO should interact with
/dev/ioasid to exchange the information both sides need and once
exchanged the control over IOMMU should be done through /dev/ioasid,
not inside VFIO.
Jason
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu
next prev parent reply other threads:[~2021-03-04 12:53 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-02 20:35 [Patch v8 00/10] vfio: expose virtual Shared Virtual Addressing to VMs Liu Yi L
2021-03-02 20:35 ` Liu Yi L
2021-03-02 20:35 ` [Patch v8 01/10] iommu: Report domain nesting info Liu Yi L
2021-03-02 20:35 ` Liu Yi L
2021-03-02 20:35 ` [Patch v8 02/10] iommu/smmu: Report empty " Liu Yi L
2021-03-02 20:35 ` Liu Yi L
2021-03-02 20:35 ` [Patch v8 03/10] vfio/type1: Report iommu nesting info to userspace Liu Yi L
2021-03-02 20:35 ` Liu Yi L
2021-03-02 12:52 ` Jason Gunthorpe
2021-03-02 12:52 ` Jason Gunthorpe
2021-03-03 9:53 ` Liu, Yi L
2021-03-03 9:53 ` Liu, Yi L
2021-03-02 20:35 ` [Patch v8 04/10] vfio/type1: Support binding guest page tables to PASID Liu Yi L
2021-03-02 20:35 ` Liu Yi L
2021-03-02 12:56 ` Jason Gunthorpe
2021-03-02 12:56 ` Jason Gunthorpe
2021-03-02 17:13 ` Jacob Pan
2021-03-02 17:13 ` Jacob Pan
2021-03-02 17:15 ` Jason Gunthorpe
2021-03-02 17:15 ` Jason Gunthorpe
2021-03-03 19:42 ` Jacob Pan
2021-03-03 19:42 ` Jacob Pan
2021-03-03 19:45 ` Jason Gunthorpe
2021-03-03 19:45 ` Jason Gunthorpe
2021-03-04 7:20 ` Liu, Yi L
2021-03-04 7:20 ` Liu, Yi L
2021-03-04 12:52 ` Jason Gunthorpe [this message]
2021-03-04 12:52 ` Jason Gunthorpe
2021-03-02 20:35 ` [Patch v8 05/10] vfio/type1: Allow invalidating first-level/stage IOMMU cache Liu Yi L
2021-03-02 20:35 ` Liu Yi L
2021-03-02 20:35 ` [Patch v8 06/10] iommu: Pass domain to sva_unbind_gpasid() Liu Yi L
2021-03-02 20:35 ` Liu Yi L
2021-03-02 20:35 ` [Patch v8 07/10] vfio/type1: Add vSVA support for IOMMU-backed mdevs Liu Yi L
2021-03-02 20:35 ` Liu Yi L
2021-03-02 20:35 ` [Patch v8 08/10] vfio/pci: Expose PCIe PASID capability to userspace Liu Yi L
2021-03-02 20:35 ` Liu Yi L
2021-03-02 20:35 ` [Patch v8 09/10] vfio: Document dual stage control Liu Yi L
2021-03-02 20:35 ` Liu Yi L
2021-03-02 20:35 ` [Patch v8 10/10] iommu/vt-d: Support reporting nesting capability info Liu Yi L
2021-03-02 20:35 ` Liu Yi L
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