All of lore.kernel.org
 help / color / mirror / Atom feed
From: Jason Gunthorpe <jgg@nvidia.com>
To: "Liu, Yi L" <yi.l.liu@intel.com>
Cc: Jason Wang <jasowang@redhat.com>,
	"Tian, Kevin" <kevin.tian@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>,
	"jacob.jun.pan@linux.intel.com" <jacob.jun.pan@linux.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>,
	"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>,
	"Michael S. Tsirkin" <mst@redhat.com>
Subject: Re: (proposal) RE: [PATCH v7 00/16] vfio: expose virtual Shared Virtual Addressing to VMs
Date: Tue, 20 Oct 2020 10:54:39 -0300	[thread overview]
Message-ID: <20201020135439.GH6219@nvidia.com> (raw)
In-Reply-To: <DM5PR11MB143545475500159AD958F006C31F0@DM5PR11MB1435.namprd11.prod.outlook.com>

On Tue, Oct 20, 2020 at 09:40:14AM +0000, Liu, Yi L wrote:

> > See previous discussion with Kevin. If I understand correctly, you expect a shared
> > L2 table if vDPA and VFIO device are using the same PASID.
> 
> L2 table sharing is not mandatory. The mapping is the same, but no need to
> assume L2 tables are shared. Especially for VFIO/vDPA devices. Even within
> a passthru framework, like VFIO, if the attributes of backend IOMMU are not
> the same, the L2 page table are not shared, but the mapping is the same.

I think not being able to share the PASID shows exactly why this VFIO
centric approach is bad.

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: "Tian, Jun J" <jun.j.tian@intel.com>,
	"Tian, Kevin" <kevin.tian@intel.com>,
	"Raj, Ashok" <ashok.raj@intel.com>,
	"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
	"jean-philippe@linaro.org" <jean-philippe@linaro.org>,
	"stefanha@gmail.com" <stefanha@gmail.com>,
	Jason Wang <jasowang@redhat.com>,
	"Michael S. Tsirkin" <mst@redhat.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>, "Wu, Hao" <hao.wu@intel.com>
Subject: Re: (proposal) RE: [PATCH v7 00/16] vfio: expose virtual Shared Virtual Addressing to VMs
Date: Tue, 20 Oct 2020 10:54:39 -0300	[thread overview]
Message-ID: <20201020135439.GH6219@nvidia.com> (raw)
In-Reply-To: <DM5PR11MB143545475500159AD958F006C31F0@DM5PR11MB1435.namprd11.prod.outlook.com>

On Tue, Oct 20, 2020 at 09:40:14AM +0000, Liu, Yi L wrote:

> > See previous discussion with Kevin. If I understand correctly, you expect a shared
> > L2 table if vDPA and VFIO device are using the same PASID.
> 
> L2 table sharing is not mandatory. The mapping is the same, but no need to
> assume L2 tables are shared. Especially for VFIO/vDPA devices. Even within
> a passthru framework, like VFIO, if the attributes of backend IOMMU are not
> the same, the L2 page table are not shared, but the mapping is the same.

I think not being able to share the PASID shows exactly why this VFIO
centric approach is bad.

Jason
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu

  reply	other threads:[~2020-10-20 13:54 UTC|newest]

Thread overview: 110+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-10-12  8:38 (proposal) RE: [PATCH v7 00/16] vfio: expose virtual Shared Virtual Addressing to VMs Tian, Kevin
2020-10-12  8:38 ` Tian, Kevin
2020-10-13  6:22 ` Jason Wang
2020-10-13  6:22   ` Jason Wang
2020-10-14  3:08   ` Tian, Kevin
2020-10-14  3:08     ` Tian, Kevin
2020-10-14 23:10     ` Alex Williamson
2020-10-14 23:10       ` Alex Williamson
2020-10-15  7:02       ` Jason Wang
2020-10-15  7:02         ` Jason Wang
2020-10-15  6:52     ` Jason Wang
2020-10-15  6:52       ` Jason Wang
2020-10-15  7:58       ` Tian, Kevin
2020-10-15  7:58         ` Tian, Kevin
2020-10-15  8:40         ` Jason Wang
2020-10-15  8:40           ` Jason Wang
2020-10-15 10:14           ` Liu, Yi L
2020-10-15 10:14             ` Liu, Yi L
2020-10-20  6:18             ` Jason Wang
2020-10-20  6:18               ` Jason Wang
2020-10-20  8:19               ` Liu, Yi L
2020-10-20  8:19                 ` Liu, Yi L
2020-10-20  9:19                 ` Jason Wang
2020-10-20  9:19                   ` Jason Wang
2020-10-20  9:40                   ` Liu, Yi L
2020-10-20  9:40                     ` Liu, Yi L
2020-10-20 13:54                     ` Jason Gunthorpe [this message]
2020-10-20 13:54                       ` Jason Gunthorpe
2020-10-20 14:00                       ` Liu, Yi L
2020-10-20 14:00                         ` Liu, Yi L
2020-10-20 14:05                         ` Jason Gunthorpe
2020-10-20 14:05                           ` Jason Gunthorpe
2020-10-20 14:09                           ` Liu, Yi L
2020-10-20 14:09                             ` Liu, Yi L
2020-10-13 10:27 ` Jean-Philippe Brucker
2020-10-13 10:27   ` Jean-Philippe Brucker
2020-10-14  2:11   ` Tian, Kevin
2020-10-14  2:11     ` Tian, Kevin
2020-10-14  3:16 ` Tian, Kevin
2020-10-14  3:16   ` Tian, Kevin
2020-10-16 15:36   ` Jason Gunthorpe
2020-10-16 15:36     ` Jason Gunthorpe
2020-10-19  8:39     ` Liu, Yi L
2020-10-19  8:39       ` Liu, Yi L
2020-10-19 14:25       ` Jason Gunthorpe
2020-10-19 14:25         ` Jason Gunthorpe
2020-10-20 10:21         ` Liu, Yi L
2020-10-20 10:21           ` Liu, Yi L
2020-10-20 14:02           ` Jason Gunthorpe
2020-10-20 14:02             ` Jason Gunthorpe
2020-10-20 14:19             ` Liu, Yi L
2020-10-20 14:19               ` Liu, Yi L
2020-10-21  2:21               ` Jason Wang
2020-10-21  2:21                 ` Jason Wang
2020-10-20 16:24             ` Raj, Ashok
2020-10-20 16:24               ` Raj, Ashok
2020-10-20 17:03               ` Jason Gunthorpe
2020-10-20 17:03                 ` Jason Gunthorpe
2020-10-20 19:51                 ` Raj, Ashok
2020-10-20 19:51                   ` Raj, Ashok
2020-10-20 19:55                   ` Jason Gunthorpe
2020-10-20 19:55                     ` Jason Gunthorpe
2020-10-20 20:08                     ` Raj, Ashok
2020-10-20 20:08                       ` Raj, Ashok
2020-10-20 20:14                       ` Jason Gunthorpe
2020-10-20 20:14                         ` Jason Gunthorpe
2020-10-20 20:27                         ` Raj, Ashok
2020-10-20 20:27                           ` Raj, Ashok
2020-10-21 11:48                           ` Jason Gunthorpe
2020-10-21 11:48                             ` Jason Gunthorpe
2020-10-21 17:51                             ` Raj, Ashok
2020-10-21 17:51                               ` Raj, Ashok
2020-10-21 18:24                               ` Jason Gunthorpe
2020-10-21 18:24                                 ` Jason Gunthorpe
2020-10-21 20:03                                 ` Raj, Ashok
2020-10-21 20:03                                   ` Raj, Ashok
2020-10-21 23:32                                   ` Jason Gunthorpe
2020-10-21 23:32                                     ` Jason Gunthorpe
2020-10-21 23:53                                     ` Raj, Ashok
2020-10-21 23:53                                       ` Raj, Ashok
2020-10-22  2:55                               ` Jason Wang
2020-10-22  2:55                                 ` Jason Wang
2020-10-22  3:54                                 ` Liu, Yi L
2020-10-22  3:54                                   ` Liu, Yi L
2020-10-22  4:38                                   ` Jason Wang
2020-10-22  4:38                                     ` Jason Wang
2020-11-03  9:52 ` joro
2020-11-03  9:52   ` joro
2020-11-03 12:56   ` Jason Gunthorpe
2020-11-03 12:56     ` Jason Gunthorpe
2020-11-03 13:18     ` joro
2020-11-03 13:18       ` joro
2020-11-03 13:23       ` Jason Gunthorpe
2020-11-03 13:23         ` Jason Gunthorpe
2020-11-03 14:03         ` joro
2020-11-03 14:03           ` joro
2020-11-03 14:06           ` Jason Gunthorpe
2020-11-03 14:06             ` Jason Gunthorpe
2020-11-03 14:35             ` joro
2020-11-03 14:35               ` joro
2020-11-03 15:22               ` Jason Gunthorpe
2020-11-03 15:22                 ` Jason Gunthorpe
2020-11-03 16:55                 ` joro
2020-11-03 16:55                   ` joro
2020-11-03 17:48                   ` Jason Gunthorpe
2020-11-03 17:48                     ` Jason Gunthorpe
2020-11-03 19:14                     ` joro
2020-11-03 19:14                       ` joro
2020-11-04 19:29                       ` Jason Gunthorpe
2020-11-04 19:29                         ` Jason Gunthorpe

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=20201020135439.GH6219@nvidia.com \
    --to=jgg@nvidia.com \
    --cc=alex.williamson@redhat.com \
    --cc=ashok.raj@intel.com \
    --cc=baolu.lu@linux.intel.com \
    --cc=eric.auger@redhat.com \
    --cc=hao.wu@intel.com \
    --cc=iommu@lists.linux-foundation.org \
    --cc=jacob.jun.pan@linux.intel.com \
    --cc=jasowang@redhat.com \
    --cc=jean-philippe@linaro.org \
    --cc=joro@8bytes.org \
    --cc=jun.j.tian@intel.com \
    --cc=kevin.tian@intel.com \
    --cc=kvm@vger.kernel.org \
    --cc=mst@redhat.com \
    --cc=peterx@redhat.com \
    --cc=stefanha@gmail.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: link
Be 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.