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From: Jason Gunthorpe <jgg@nvidia.com>
To: "Luck, Tony" <tony.luck@intel.com>
Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>,
	"iommu@lists.linux-foundation.org"
	<iommu@lists.linux-foundation.org>,
	LKML <linux-kernel@vger.kernel.org>,
	Joerg Roedel <joro@8bytes.org>,
	Christoph Hellwig <hch@infradead.org>,
	Lu Baolu <baolu.lu@linux.intel.com>,
	Jean-Philippe Brucker <jean-philippe@linaro.com>,
	"Pan, Jacob jun" <jacob.jun.pan@intel.com>,
	"Raj, Ashok" <ashok.raj@intel.com>,
	"Kumar, Sanjay K" <sanjay.k.kumar@intel.com>,
	"Jiang, Dave" <dave.jiang@intel.com>,
	"Zanussi, Tom" <tom.zanussi@intel.com>,
	"Williams, Dan J" <dan.j.williams@intel.com>,
	"Tian, Kevin" <kevin.tian@intel.com>,
	"Liu, Yi L" <yi.l.liu@intel.com>
Subject: Re: [PATCH v2 3/8] iommu/vt-d: Implement device_pasid domain attach ops
Date: Wed, 16 Mar 2022 21:04:10 -0300	[thread overview]
Message-ID: <20220317000410.GU11336@nvidia.com> (raw)
In-Reply-To: <17d73d88e08047f09636cf39edd69892@intel.com>

On Wed, Mar 16, 2022 at 10:23:26PM +0000, Luck, Tony wrote:

> Kernel users (ring0) can supply any PASID when they use
> the ENQCMDS instruction. Is that what you mean when you
> say "real applications"?

I'm not talking about ENQCMD at all

I'm saying I don't see much utility to have two PASIDs assigned to the
same device that perform the same IOVA translation.

So I would expect the list of attachments in an iommu_domain to have
exactly one device in it and multiple PASIDs to the same device from
the same iommu_domain is a oddball corner case we don't need to
optimize for, beyond being able to allow it to happen.

Jason

WARNING: multiple messages have this Message-ID (diff)
From: Jason Gunthorpe via iommu <iommu@lists.linux-foundation.org>
To: "Luck, Tony" <tony.luck@intel.com>
Cc: "Tian, Kevin" <kevin.tian@intel.com>,
	"Jiang, Dave" <dave.jiang@intel.com>,
	"Raj, Ashok" <ashok.raj@intel.com>,
	"Zanussi, Tom" <tom.zanussi@intel.com>,
	"Kumar, Sanjay K" <sanjay.k.kumar@intel.com>,
	LKML <linux-kernel@vger.kernel.org>,
	Christoph Hellwig <hch@infradead.org>,
	"iommu@lists.linux-foundation.org"
	<iommu@lists.linux-foundation.org>,
	"Pan, Jacob jun" <jacob.jun.pan@intel.com>,
	"Williams, Dan J" <dan.j.williams@intel.com>,
	Jean-Philippe Brucker <jean-philippe@linaro.com>
Subject: Re: [PATCH v2 3/8] iommu/vt-d: Implement device_pasid domain attach ops
Date: Wed, 16 Mar 2022 21:04:10 -0300	[thread overview]
Message-ID: <20220317000410.GU11336@nvidia.com> (raw)
In-Reply-To: <17d73d88e08047f09636cf39edd69892@intel.com>

On Wed, Mar 16, 2022 at 10:23:26PM +0000, Luck, Tony wrote:

> Kernel users (ring0) can supply any PASID when they use
> the ENQCMDS instruction. Is that what you mean when you
> say "real applications"?

I'm not talking about ENQCMD at all

I'm saying I don't see much utility to have two PASIDs assigned to the
same device that perform the same IOVA translation.

So I would expect the list of attachments in an iommu_domain to have
exactly one device in it and multiple PASIDs to the same device from
the same iommu_domain is a oddball corner case we don't need to
optimize for, beyond being able to allow it to happen.

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

  reply	other threads:[~2022-03-17  0:04 UTC|newest]

Thread overview: 122+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-03-15  5:07 [PATCH v2 0/8] Enable PASID for DMA API users Jacob Pan
2022-03-15  5:07 ` Jacob Pan
2022-03-15  5:07 ` [PATCH v2 1/8] iommu: Assign per device max PASID Jacob Pan
2022-03-15  5:07   ` Jacob Pan
2022-03-15  5:07 ` [PATCH v2 2/8] iommu: Add attach/detach_dev_pasid domain ops Jacob Pan
2022-03-15  5:07   ` Jacob Pan
2022-03-15 10:24   ` Tian, Kevin
2022-03-15 10:24     ` Tian, Kevin
2022-03-15 11:26   ` Jean-Philippe Brucker
2022-03-15 11:26     ` Jean-Philippe Brucker
2022-03-15 11:49     ` Tian, Kevin
2022-03-15 11:49       ` Tian, Kevin
2022-03-15 16:11       ` Jacob Pan
2022-03-15 16:11         ` Jacob Pan
2022-03-18 12:01       ` Lu Baolu
2022-03-18 12:01         ` Lu Baolu
2022-03-18 13:50         ` Jason Gunthorpe
2022-03-18 13:50           ` Jason Gunthorpe via iommu
2022-03-18 11:52   ` Lu Baolu
2022-03-18 11:52     ` Lu Baolu
2022-03-18 13:48     ` Jason Gunthorpe
2022-03-18 13:48       ` Jason Gunthorpe via iommu
2022-03-15  5:07 ` [PATCH v2 3/8] iommu/vt-d: Implement device_pasid domain attach ops Jacob Pan
2022-03-15  5:07   ` Jacob Pan
2022-03-15 10:33   ` Tian, Kevin
2022-03-15 10:33     ` Tian, Kevin
2022-03-15 22:23     ` Jacob Pan
2022-03-15 22:23       ` Jacob Pan
2022-03-15 14:33   ` Jason Gunthorpe
2022-03-15 14:33     ` Jason Gunthorpe via iommu
2022-03-15 22:36     ` Jacob Pan
2022-03-15 22:36       ` Jacob Pan
2022-03-15 23:04       ` Jason Gunthorpe
2022-03-15 23:04         ` Jason Gunthorpe via iommu
2022-03-16 20:50         ` Jacob Pan
2022-03-16 20:50           ` Jacob Pan
2022-03-16 22:15           ` Jason Gunthorpe
2022-03-16 22:15             ` Jason Gunthorpe via iommu
2022-03-16 22:23             ` Luck, Tony
2022-03-16 22:23               ` Luck, Tony
2022-03-17  0:04               ` Jason Gunthorpe [this message]
2022-03-17  0:04                 ` Jason Gunthorpe via iommu
2022-03-18  5:47                 ` Tian, Kevin
2022-03-18  5:47                   ` Tian, Kevin
2022-03-18 13:47                   ` Jason Gunthorpe
2022-03-18 13:47                     ` Jason Gunthorpe via iommu
2022-03-17  0:49             ` Jacob Pan
2022-03-17  0:49               ` Jacob Pan
2022-03-17 13:23               ` Jason Gunthorpe
2022-03-17 13:23                 ` Jason Gunthorpe via iommu
2022-03-17 18:23                 ` Jacob Pan
2022-03-17 18:23                   ` Jacob Pan
2022-03-16  7:41     ` Tian, Kevin
2022-03-16  7:41       ` Tian, Kevin
2022-03-16 21:01       ` Jacob Pan
2022-03-16 21:01         ` Jacob Pan
2022-03-18  5:33         ` Tian, Kevin
2022-03-18  5:33           ` Tian, Kevin
2022-03-28 21:41           ` Jacob Pan
2022-03-28 21:41             ` Jacob Pan
2022-03-16  7:39   ` Tian, Kevin
2022-03-16  7:39     ` Tian, Kevin
2022-03-16 20:51     ` Jacob Pan
2022-03-16 20:51       ` Jacob Pan
2022-03-15  5:07 ` [PATCH v2 4/8] iommu/vt-d: Use device_pasid attach op for RID2PASID Jacob Pan
2022-03-15  5:07   ` Jacob Pan
2022-03-16  7:54   ` Tian, Kevin
2022-03-16  7:54     ` Tian, Kevin
2022-03-17 20:45     ` Jacob Pan
2022-03-17 20:45       ` Jacob Pan
2022-03-15  5:07 ` [PATCH v2 5/8] iommu: Add PASID support for DMA mapping API users Jacob Pan
2022-03-15  5:07   ` Jacob Pan
2022-03-15 11:16   ` Robin Murphy
2022-03-15 11:16     ` Robin Murphy
2022-03-15 14:22     ` Jason Gunthorpe
2022-03-15 14:22       ` Jason Gunthorpe via iommu
2022-03-15 16:31       ` Jacob Pan
2022-03-15 16:31         ` Jacob Pan
2022-03-15 17:05         ` Jason Gunthorpe
2022-03-15 17:05           ` Jason Gunthorpe via iommu
2022-03-15 21:24           ` Jacob Pan
2022-03-15 21:24             ` Jacob Pan
2022-03-16 10:32             ` Tian, Kevin
2022-03-16 10:32               ` Tian, Kevin
2022-03-16  8:41       ` Tian, Kevin
2022-03-16  8:41         ` Tian, Kevin
2022-03-16 14:07         ` Jason Gunthorpe
2022-03-16 14:07           ` Jason Gunthorpe via iommu
2022-03-15 14:35   ` Jason Gunthorpe
2022-03-15 14:35     ` Jason Gunthorpe via iommu
2022-03-15 16:38     ` Jacob Pan
2022-03-15 16:38       ` Jacob Pan
2022-03-15 23:05       ` Jason Gunthorpe
2022-03-15 23:05         ` Jason Gunthorpe via iommu
2022-03-18 12:43   ` Lu Baolu
2022-03-18 12:43     ` Lu Baolu
2022-03-28 21:44     ` Jacob Pan
2022-03-28 21:44       ` Jacob Pan
2022-03-15  5:07 ` [PATCH v2 6/8] dmaengine: idxd: Use DMA API for in-kernel DMA with PASID Jacob Pan
2022-03-15  5:07   ` Jacob Pan
2022-03-18  6:10   ` Tian, Kevin
2022-03-18  6:10     ` Tian, Kevin
2022-03-29 17:39     ` Jacob Pan
2022-03-29 17:39       ` Jacob Pan
2022-03-15  5:07 ` [PATCH v2 7/8] iommu/vt-d: Delete supervisor/kernel SVA Jacob Pan
2022-03-15  5:07   ` Jacob Pan
2022-03-18  6:16   ` Tian, Kevin
2022-03-18  6:16     ` Tian, Kevin
2022-03-29 17:42     ` Jacob Pan
2022-03-29 17:42       ` Jacob Pan
2022-03-15  5:07 ` [PATCH v2 8/8] iommu: Remove unused driver data in sva_bind_device Jacob Pan
2022-03-15  5:07   ` Jacob Pan
2022-03-15 11:37   ` Jean-Philippe Brucker
2022-03-15 11:37     ` Jean-Philippe Brucker
2022-03-15  5:07 ` [PATCH v2 9/9] dmaengine: idxd: separate user and kernel pasid enabling Jacob Pan
2022-03-15  5:07   ` Jacob Pan
2022-03-18  6:28   ` Tian, Kevin
2022-03-18  6:28     ` Tian, Kevin
2022-03-15  8:16 ` [PATCH v2 0/8] Enable PASID for DMA API users Tian, Kevin
2022-03-15  8:16   ` Tian, Kevin
2022-03-15 15:49   ` Jacob Pan
2022-03-15 15:49     ` Jacob Pan

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