From: Jason Gunthorpe <jgg@nvidia.com>
To: "Tian, Kevin" <kevin.tian@intel.com>
Cc: Alex Williamson <alex.williamson@redhat.com>,
Joerg Roedel <joro@8bytes.org>,
Jean-Philippe Brucker <jean-philippe@linaro.org>,
David Gibson <david@gibson.dropbear.id.au>,
Jason Wang <jasowang@redhat.com>,
"parav@mellanox.com" <parav@mellanox.com>,
"Enrico Weigelt, metux IT consult" <lkml@metux.net>,
Paolo Bonzini <pbonzini@redhat.com>,
Shenming Lu <lushenming@huawei.com>,
Eric Auger <eric.auger@redhat.com>,
Jonathan Corbet <corbet@lwn.net>,
"Raj, Ashok" <ashok.raj@intel.com>,
"Liu, Yi L" <yi.l.liu@intel.com>, "Wu, Hao" <hao.wu@intel.com>,
"Jiang, Dave" <dave.jiang@intel.com>,
Jacob Pan <jacob.jun.pan@linux.intel.com>,
Kirti Wankhede <kwankhede@nvidia.com>,
Robin Murphy <robin.murphy@arm.com>,
"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
"iommu@lists.linux-foundation.org"
<iommu@lists.linux-foundation.org>,
David Woodhouse <dwmw2@infradead.org>,
LKML <linux-kernel@vger.kernel.org>,
Lu Baolu <baolu.lu@linux.intel.com>
Subject: Re: Plan for /dev/ioasid RFC v2
Date: Mon, 14 Jun 2021 10:38:19 -0300 [thread overview]
Message-ID: <20210614133819.GH1002214@nvidia.com> (raw)
In-Reply-To: <MWHPR11MB1886C2A0A8AA3000EBD5F8E18C319@MWHPR11MB1886.namprd11.prod.outlook.com>
On Mon, Jun 14, 2021 at 03:09:31AM +0000, Tian, Kevin wrote:
> If a device can be always blocked from accessing memory in the IOMMU
> before it's bound to a driver or more specifically before the driver
> moves it to a new security context, then there is no need for VFIO
> to track whether IOASIDfd has taken over ownership of the DMA
> context for all devices within a group.
I've been assuming we'd do something like this, where when a device is
first turned into a VFIO it tells the IOMMU layer that this device
should be DMA blocked unless an IOASID is attached to
it. Disconnecting an IOASID returns it to blocked.
> If this works I didn't see the need for vfio to keep the sequence.
> VFIO still keeps group fd to claim ownership of all devices in a
> group.
As Alex says you still have to deal with the problem that device A in
a group can gain control of device B in the same group.
This means device A and B can not be used from to two different
security contexts.
If the /dev/iommu FD is the security context then the tracking is
needed there.
Jason
WARNING: multiple messages have this Message-ID (diff)
From: Jason Gunthorpe <jgg@nvidia.com>
To: "Tian, Kevin" <kevin.tian@intel.com>
Cc: "kvm@vger.kernel.org" <kvm@vger.kernel.org>,
Jason Wang <jasowang@redhat.com>,
Kirti Wankhede <kwankhede@nvidia.com>,
Jean-Philippe Brucker <jean-philippe@linaro.org>,
"Jiang, Dave" <dave.jiang@intel.com>,
"Raj, Ashok" <ashok.raj@intel.com>,
Jonathan Corbet <corbet@lwn.net>,
"parav@mellanox.com" <parav@mellanox.com>,
Alex Williamson <alex.williamson@redhat.com>,
"Enrico Weigelt, metux IT consult" <lkml@metux.net>,
David Gibson <david@gibson.dropbear.id.au>,
Robin Murphy <robin.murphy@arm.com>,
LKML <linux-kernel@vger.kernel.org>,
Shenming Lu <lushenming@huawei.com>,
"iommu@lists.linux-foundation.org"
<iommu@lists.linux-foundation.org>,
Paolo Bonzini <pbonzini@redhat.com>,
David Woodhouse <dwmw2@infradead.org>
Subject: Re: Plan for /dev/ioasid RFC v2
Date: Mon, 14 Jun 2021 10:38:19 -0300 [thread overview]
Message-ID: <20210614133819.GH1002214@nvidia.com> (raw)
In-Reply-To: <MWHPR11MB1886C2A0A8AA3000EBD5F8E18C319@MWHPR11MB1886.namprd11.prod.outlook.com>
On Mon, Jun 14, 2021 at 03:09:31AM +0000, Tian, Kevin wrote:
> If a device can be always blocked from accessing memory in the IOMMU
> before it's bound to a driver or more specifically before the driver
> moves it to a new security context, then there is no need for VFIO
> to track whether IOASIDfd has taken over ownership of the DMA
> context for all devices within a group.
I've been assuming we'd do something like this, where when a device is
first turned into a VFIO it tells the IOMMU layer that this device
should be DMA blocked unless an IOASID is attached to
it. Disconnecting an IOASID returns it to blocked.
> If this works I didn't see the need for vfio to keep the sequence.
> VFIO still keeps group fd to claim ownership of all devices in a
> group.
As Alex says you still have to deal with the problem that device A in
a group can gain control of device B in the same group.
This means device A and B can not be used from to two different
security contexts.
If the /dev/iommu FD is the security context then the tracking is
needed there.
Jason
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu
next prev parent reply other threads:[~2021-06-14 13:38 UTC|newest]
Thread overview: 162+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-07 2:58 Plan for /dev/ioasid RFC v2 Tian, Kevin
2021-06-07 2:58 ` Tian, Kevin
2021-06-09 8:14 ` Eric Auger
2021-06-09 8:14 ` Eric Auger
2021-06-09 9:37 ` Tian, Kevin
2021-06-09 9:37 ` Tian, Kevin
2021-06-09 10:14 ` Eric Auger
2021-06-09 10:14 ` Eric Auger
2021-06-09 9:01 ` Leon Romanovsky
2021-06-09 9:01 ` Leon Romanovsky
2021-06-09 9:43 ` Tian, Kevin
2021-06-09 9:43 ` Tian, Kevin
2021-06-09 12:24 ` Joerg Roedel
2021-06-09 12:24 ` Joerg Roedel
2021-06-09 12:39 ` Jason Gunthorpe
2021-06-09 12:39 ` Jason Gunthorpe
2021-06-09 13:32 ` Joerg Roedel
2021-06-09 13:32 ` Joerg Roedel
2021-06-09 15:00 ` Jason Gunthorpe
2021-06-09 15:00 ` Jason Gunthorpe
2021-06-09 15:51 ` Joerg Roedel
2021-06-09 15:51 ` Joerg Roedel
2021-06-09 16:15 ` Alex Williamson
2021-06-09 16:15 ` Alex Williamson
2021-06-09 16:27 ` Alex Williamson
2021-06-09 16:27 ` Alex Williamson
2021-06-09 18:49 ` Jason Gunthorpe
2021-06-09 18:49 ` Jason Gunthorpe
2021-06-10 15:38 ` Alex Williamson
2021-06-10 15:38 ` Alex Williamson
2021-06-11 0:58 ` Tian, Kevin
2021-06-11 0:58 ` Tian, Kevin
2021-06-11 21:38 ` Alex Williamson
2021-06-11 21:38 ` Alex Williamson
2021-06-14 3:09 ` Tian, Kevin
2021-06-14 3:09 ` Tian, Kevin
2021-06-14 3:22 ` Alex Williamson
2021-06-14 3:22 ` Alex Williamson
2021-06-15 1:05 ` Tian, Kevin
2021-06-15 1:05 ` Tian, Kevin
2021-06-14 13:38 ` Jason Gunthorpe [this message]
2021-06-14 13:38 ` Jason Gunthorpe
2021-06-15 1:21 ` Tian, Kevin
2021-06-15 1:21 ` Tian, Kevin
2021-06-15 16:56 ` Alex Williamson
2021-06-15 16:56 ` Alex Williamson
2021-06-16 6:53 ` Tian, Kevin
2021-06-16 6:53 ` Tian, Kevin
2021-06-24 4:50 ` David Gibson
2021-06-24 4:50 ` David Gibson
2021-06-11 16:45 ` Jason Gunthorpe
2021-06-11 16:45 ` Jason Gunthorpe
2021-06-11 19:38 ` Alex Williamson
2021-06-11 19:38 ` Alex Williamson
2021-06-12 1:28 ` Jason Gunthorpe
2021-06-12 1:28 ` Jason Gunthorpe
2021-06-12 16:57 ` Alex Williamson
2021-06-12 16:57 ` Alex Williamson
2021-06-14 14:07 ` Jason Gunthorpe
2021-06-14 14:07 ` Jason Gunthorpe
2021-06-14 16:28 ` Alex Williamson
2021-06-14 16:28 ` Alex Williamson
2021-06-14 19:40 ` Jason Gunthorpe
2021-06-14 19:40 ` Jason Gunthorpe
2021-06-15 2:31 ` Tian, Kevin
2021-06-15 2:31 ` Tian, Kevin
2021-06-15 16:12 ` Alex Williamson
2021-06-15 16:12 ` Alex Williamson
2021-06-16 6:43 ` Tian, Kevin
2021-06-16 6:43 ` Tian, Kevin
2021-06-16 19:39 ` Alex Williamson
2021-06-16 19:39 ` Alex Williamson
2021-06-17 3:39 ` Liu Yi L
2021-06-17 3:39 ` Liu Yi L
2021-06-17 7:31 ` Tian, Kevin
2021-06-17 7:31 ` Tian, Kevin
2021-06-17 21:14 ` Alex Williamson
2021-06-17 21:14 ` Alex Williamson
2021-06-18 0:19 ` Jason Gunthorpe
2021-06-18 0:19 ` Jason Gunthorpe
2021-06-18 16:57 ` Tian, Kevin
2021-06-18 16:57 ` Tian, Kevin
2021-06-18 18:23 ` Jason Gunthorpe
2021-06-18 18:23 ` Jason Gunthorpe
2021-06-25 10:27 ` Tian, Kevin
2021-06-25 10:27 ` Tian, Kevin
2021-06-25 14:36 ` Jason Gunthorpe
2021-06-25 14:36 ` Jason Gunthorpe
2021-06-28 1:09 ` Tian, Kevin
2021-06-28 1:09 ` Tian, Kevin
2021-06-28 22:31 ` Alex Williamson
2021-06-28 22:31 ` Alex Williamson
2021-06-28 22:48 ` Jason Gunthorpe
2021-06-28 22:48 ` Jason Gunthorpe
2021-06-28 23:09 ` Alex Williamson
2021-06-28 23:09 ` Alex Williamson
2021-06-28 23:13 ` Jason Gunthorpe
2021-06-28 23:13 ` Jason Gunthorpe
2021-06-29 0:26 ` Tian, Kevin
2021-06-29 0:26 ` Tian, Kevin
2021-06-29 0:28 ` Tian, Kevin
2021-06-29 0:28 ` Tian, Kevin
2021-06-29 0:43 ` Tian, Kevin
2021-06-29 0:43 ` Tian, Kevin
2021-06-28 2:03 ` Tian, Kevin
2021-06-28 2:03 ` Tian, Kevin
2021-06-28 14:41 ` Jason Gunthorpe
2021-06-28 14:41 ` Jason Gunthorpe
2021-06-28 6:45 ` Tian, Kevin
2021-06-28 6:45 ` Tian, Kevin
2021-06-28 16:26 ` Jason Gunthorpe
2021-06-28 16:26 ` Jason Gunthorpe
2021-06-24 4:26 ` David Gibson
2021-06-24 4:26 ` David Gibson
2021-06-24 5:59 ` Tian, Kevin
2021-06-24 5:59 ` Tian, Kevin
2021-06-24 12:22 ` Lu Baolu
2021-06-24 12:22 ` Lu Baolu
2021-06-24 4:23 ` David Gibson
2021-06-24 4:23 ` David Gibson
2021-06-18 0:52 ` Jason Gunthorpe
2021-06-18 0:52 ` Jason Gunthorpe
2021-06-18 13:47 ` Joerg Roedel
2021-06-18 13:47 ` Joerg Roedel
2021-06-18 15:15 ` Jason Gunthorpe
2021-06-18 15:15 ` Jason Gunthorpe
2021-06-18 15:37 ` Raj, Ashok
2021-06-18 15:37 ` Raj, Ashok
2021-06-18 15:51 ` Alex Williamson
2021-06-18 15:51 ` Alex Williamson
2021-06-24 4:29 ` David Gibson
2021-06-24 4:29 ` David Gibson
2021-06-24 11:56 ` Jason Gunthorpe
2021-06-24 11:56 ` Jason Gunthorpe
2021-06-18 0:10 ` Jason Gunthorpe
2021-06-18 0:10 ` Jason Gunthorpe
2021-06-17 5:29 ` David Gibson
2021-06-17 5:29 ` David Gibson
2021-06-17 5:02 ` David Gibson
2021-06-17 5:02 ` David Gibson
2021-06-17 23:04 ` Jason Gunthorpe
2021-06-17 23:04 ` Jason Gunthorpe
2021-06-24 4:37 ` David Gibson
2021-06-24 4:37 ` David Gibson
2021-06-24 11:57 ` Jason Gunthorpe
2021-06-24 11:57 ` Jason Gunthorpe
2021-06-10 5:50 ` Lu Baolu
2021-06-10 5:50 ` Lu Baolu
2021-06-17 5:22 ` David Gibson
2021-06-17 5:22 ` David Gibson
2021-06-18 5:21 ` Lu Baolu
2021-06-18 5:21 ` Lu Baolu
2021-06-24 4:03 ` David Gibson
2021-06-24 4:03 ` David Gibson
2021-06-24 13:42 ` Lu Baolu
2021-06-24 13:42 ` Lu Baolu
2021-06-17 4:45 ` David Gibson
2021-06-17 4:45 ` David Gibson
2021-06-17 23:10 ` Jason Gunthorpe
2021-06-17 23:10 ` Jason Gunthorpe
2021-06-24 4:07 ` David Gibson
2021-06-24 4:07 ` David Gibson
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=20210614133819.GH1002214@nvidia.com \
--to=jgg@nvidia.com \
--cc=alex.williamson@redhat.com \
--cc=ashok.raj@intel.com \
--cc=baolu.lu@linux.intel.com \
--cc=corbet@lwn.net \
--cc=dave.jiang@intel.com \
--cc=david@gibson.dropbear.id.au \
--cc=dwmw2@infradead.org \
--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=kevin.tian@intel.com \
--cc=kvm@vger.kernel.org \
--cc=kwankhede@nvidia.com \
--cc=linux-kernel@vger.kernel.org \
--cc=lkml@metux.net \
--cc=lushenming@huawei.com \
--cc=parav@mellanox.com \
--cc=pbonzini@redhat.com \
--cc=robin.murphy@arm.com \
--cc=yi.l.liu@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.