From: Jason Gunthorpe via iommu <iommu@lists.linux-foundation.org>
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 \(alex.williamson@redhat.com\)"
<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: [RFC v2] /dev/iommu uAPI proposal
Date: Thu, 5 Aug 2021 08:27:13 -0300 [thread overview]
Message-ID: <20210805112713.GN1721383@nvidia.com> (raw)
In-Reply-To: <BN9PR11MB54330D97D0935F1C1E0E346C8CF19@BN9PR11MB5433.namprd11.prod.outlook.com>
On Wed, Aug 04, 2021 at 10:59:21PM +0000, Tian, Kevin wrote:
> > From: Jason Gunthorpe <jgg@nvidia.com>
> > Sent: Wednesday, August 4, 2021 10:05 PM
> >
> > On Mon, Aug 02, 2021 at 02:49:44AM +0000, Tian, Kevin wrote:
> >
> > > Can you elaborate? IMO the user only cares about the label (device cookie
> > > plus optional vPASID) which is generated by itself when doing the attaching
> > > call, and expects this virtual label being used in various spots (invalidation,
> > > page fault, etc.). How the system labels the traffic (the physical RID or RID+
> > > PASID) should be completely invisible to userspace.
> >
> > I don't think that is true if the vIOMMU driver is also emulating
> > PASID. Presumably the same is true for other PASID-like schemes.
> >
>
> I'm getting even more confused with this comment. Isn't it the
> consensus from day one that physical PASID should not be exposed
> to userspace as doing so breaks live migration?
Uh, no?
> with PASID emulation vIOMMU only cares about vPASID instead of
> pPASID, and the uAPI only requires user to register vPASID instead
> of reporting pPASID back to userspace...
vPASID is only a feature of one device in existance, so we can't make
vPASID mandatory.
Jason
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WARNING: multiple messages have this Message-ID (diff)
From: Jason Gunthorpe <jgg@nvidia.com>
To: "Tian, Kevin" <kevin.tian@intel.com>
Cc: David Gibson <david@gibson.dropbear.id.au>,
"Alex Williamson (alex.williamson@redhat.com)"
<alex.williamson@redhat.com>,
Jean-Philippe Brucker <jean-philippe@linaro.org>,
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>,
Joerg Roedel <joro@8bytes.org>,
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: [RFC v2] /dev/iommu uAPI proposal
Date: Thu, 5 Aug 2021 08:27:13 -0300 [thread overview]
Message-ID: <20210805112713.GN1721383@nvidia.com> (raw)
In-Reply-To: <BN9PR11MB54330D97D0935F1C1E0E346C8CF19@BN9PR11MB5433.namprd11.prod.outlook.com>
On Wed, Aug 04, 2021 at 10:59:21PM +0000, Tian, Kevin wrote:
> > From: Jason Gunthorpe <jgg@nvidia.com>
> > Sent: Wednesday, August 4, 2021 10:05 PM
> >
> > On Mon, Aug 02, 2021 at 02:49:44AM +0000, Tian, Kevin wrote:
> >
> > > Can you elaborate? IMO the user only cares about the label (device cookie
> > > plus optional vPASID) which is generated by itself when doing the attaching
> > > call, and expects this virtual label being used in various spots (invalidation,
> > > page fault, etc.). How the system labels the traffic (the physical RID or RID+
> > > PASID) should be completely invisible to userspace.
> >
> > I don't think that is true if the vIOMMU driver is also emulating
> > PASID. Presumably the same is true for other PASID-like schemes.
> >
>
> I'm getting even more confused with this comment. Isn't it the
> consensus from day one that physical PASID should not be exposed
> to userspace as doing so breaks live migration?
Uh, no?
> with PASID emulation vIOMMU only cares about vPASID instead of
> pPASID, and the uAPI only requires user to register vPASID instead
> of reporting pPASID back to userspace...
vPASID is only a feature of one device in existance, so we can't make
vPASID mandatory.
Jason
next prev parent reply other threads:[~2021-08-05 11:27 UTC|newest]
Thread overview: 120+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-09 7:48 [RFC v2] /dev/iommu uAPI proposal Tian, Kevin
2021-07-09 7:48 ` Tian, Kevin
2021-07-09 21:50 ` Alex Williamson
2021-07-09 21:50 ` Alex Williamson
2021-07-12 1:22 ` Tian, Kevin
2021-07-12 1:22 ` Tian, Kevin
2021-07-12 18:41 ` Alex Williamson
2021-07-12 18:41 ` Alex Williamson
2021-07-12 23:41 ` Tian, Kevin
2021-07-12 23:41 ` Tian, Kevin
2021-07-12 23:56 ` Tian, Kevin
2021-07-12 23:56 ` Tian, Kevin
2021-07-13 12:55 ` Jason Gunthorpe
2021-07-13 12:55 ` Jason Gunthorpe
2021-07-13 16:26 ` Alex Williamson
2021-07-13 16:26 ` Alex Williamson
2021-07-13 16:32 ` Jason Gunthorpe
2021-07-13 16:32 ` Jason Gunthorpe
2021-07-13 22:48 ` Tian, Kevin
2021-07-13 22:48 ` Tian, Kevin
2021-07-13 23:02 ` Jason Gunthorpe
2021-07-13 23:02 ` Jason Gunthorpe
2021-07-13 23:20 ` Tian, Kevin
2021-07-13 23:20 ` Tian, Kevin
2021-07-13 23:22 ` Jason Gunthorpe
2021-07-13 23:22 ` Jason Gunthorpe
2021-07-13 23:24 ` Tian, Kevin
2021-07-13 23:24 ` Tian, Kevin
2021-07-15 3:20 ` Shenming Lu
2021-07-15 3:20 ` Shenming Lu
2021-07-15 3:55 ` Tian, Kevin
2021-07-15 3:55 ` Tian, Kevin
2021-07-15 6:29 ` Shenming Lu
2021-07-15 6:29 ` Shenming Lu
2021-07-15 6:49 ` Tian, Kevin
2021-07-15 6:49 ` Tian, Kevin
2021-07-15 8:14 ` Shenming Lu
2021-07-15 8:14 ` Shenming Lu
2021-07-15 12:48 ` Jason Gunthorpe via iommu
2021-07-15 12:48 ` Jason Gunthorpe
2021-07-15 13:57 ` Raj, Ashok
2021-07-15 13:57 ` Raj, Ashok
2021-07-15 15:23 ` Jason Gunthorpe via iommu
2021-07-15 15:23 ` Jason Gunthorpe
2021-07-15 16:21 ` Raj, Ashok
2021-07-15 16:21 ` Raj, Ashok
2021-07-15 17:18 ` Jason Gunthorpe via iommu
2021-07-15 17:18 ` Jason Gunthorpe
2021-07-15 17:48 ` Raj, Ashok
2021-07-15 17:48 ` Raj, Ashok
2021-07-15 17:53 ` Jason Gunthorpe via iommu
2021-07-15 17:53 ` Jason Gunthorpe
2021-07-15 18:05 ` Raj, Ashok
2021-07-15 18:05 ` Raj, Ashok
2021-07-15 18:13 ` Jason Gunthorpe via iommu
2021-07-15 18:13 ` Jason Gunthorpe
2021-07-16 1:20 ` Tian, Kevin
2021-07-16 1:20 ` Tian, Kevin
2021-07-16 12:20 ` Shenming Lu
2021-07-16 12:20 ` Shenming Lu
2021-07-21 2:13 ` Tian, Kevin
2021-07-21 2:13 ` Tian, Kevin
2021-07-22 16:30 ` Jason Gunthorpe via iommu
2021-07-22 16:30 ` Jason Gunthorpe
2021-07-16 18:30 ` Jason Gunthorpe via iommu
2021-07-16 18:30 ` Jason Gunthorpe
2021-07-21 2:11 ` Tian, Kevin
2021-07-21 2:11 ` Tian, Kevin
2021-07-26 4:50 ` David Gibson
2021-07-26 4:50 ` David Gibson
2021-07-28 4:04 ` Tian, Kevin
2021-07-28 4:04 ` Tian, Kevin
2021-08-03 1:50 ` David Gibson
2021-08-03 1:50 ` David Gibson
2021-08-03 3:19 ` Tian, Kevin
2021-08-03 3:19 ` Tian, Kevin
2021-08-06 4:45 ` David Gibson
2021-08-06 4:45 ` David Gibson
2021-08-06 12:32 ` Jason Gunthorpe via iommu
2021-08-06 12:32 ` Jason Gunthorpe
2021-08-10 6:10 ` David Gibson
2021-08-10 6:10 ` David Gibson
2021-08-09 8:34 ` Tian, Kevin
2021-08-09 8:34 ` Tian, Kevin
2021-08-10 4:47 ` David Gibson
2021-08-10 4:47 ` David Gibson
2021-08-10 6:04 ` Tian, Kevin
2021-08-10 6:04 ` Tian, Kevin
2021-07-30 14:51 ` Jason Gunthorpe via iommu
2021-07-30 14:51 ` Jason Gunthorpe
2021-08-02 2:49 ` Tian, Kevin
2021-08-02 2:49 ` Tian, Kevin
2021-08-04 14:04 ` Jason Gunthorpe via iommu
2021-08-04 14:04 ` Jason Gunthorpe
2021-08-04 22:59 ` Tian, Kevin
2021-08-04 22:59 ` Tian, Kevin
2021-08-05 11:27 ` Jason Gunthorpe via iommu [this message]
2021-08-05 11:27 ` Jason Gunthorpe
2021-08-05 22:44 ` Tian, Kevin
2021-08-05 22:44 ` Tian, Kevin
2021-08-06 4:47 ` David Gibson
2021-08-06 4:47 ` David Gibson
2021-08-03 1:58 ` David Gibson
2021-08-03 1:58 ` David Gibson
2021-08-04 14:07 ` Jason Gunthorpe via iommu
2021-08-04 14:07 ` Jason Gunthorpe
2021-08-06 4:24 ` David Gibson
2021-08-06 4:24 ` David Gibson
2021-07-26 8:14 ` Jean-Philippe Brucker
2021-07-26 8:14 ` Jean-Philippe Brucker
2021-07-28 4:05 ` Tian, Kevin
2021-07-28 4:05 ` Tian, Kevin
2021-08-04 15:59 ` Eric Auger
2021-08-04 15:59 ` Eric Auger
2021-08-05 0:36 ` Tian, Kevin
2021-08-05 0:36 ` Tian, Kevin
2021-08-10 7:17 ` Eric Auger
2021-08-10 7:17 ` Eric Auger
2021-08-10 9:00 ` Tian, Kevin
2021-08-10 9:00 ` Tian, Kevin
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