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From: Jason Gunthorpe <jgg@nvidia.com>
To: Lu Baolu <baolu.lu@linux.intel.com>
Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>,
	Jean-Philippe Brucker <jean-philippe@linaro.org>,
	LKML <linux-kernel@vger.kernel.org>,
	iommu@lists.linux-foundation.org, Joerg Roedel <joro@8bytes.org>,
	Jean-Philippe Brucker <jean-philippe@linaro.com>,
	Yi Liu <yi.l.liu@intel.com>, Raj Ashok <ashok.raj@intel.com>,
	"Tian, Kevin" <kevin.tian@intel.com>,
	Dave Jiang <dave.jiang@intel.com>,
	wangzhou1@hisilicon.com, zhangfei.gao@linaro.org,
	vkoul@kernel.org
Subject: Re: [PATCH 2/2] iommu/sva: Remove mm parameter from SVA bind API
Date: Thu, 15 Apr 2021 08:59:41 -0300	[thread overview]
Message-ID: <20210415115941.GE1370958@nvidia.com> (raw)
In-Reply-To: <eb700675-f698-62e5-bbab-3d199ff58dcb@linux.intel.com>

On Thu, Apr 15, 2021 at 01:33:24PM +0800, Lu Baolu wrote:
> Hi Jason,
> 
> On 4/14/21 7:26 PM, Jason Gunthorpe wrote:
> > On Wed, Apr 14, 2021 at 02:22:09PM +0800, Lu Baolu wrote:
> > 
> > > I still worry about supervisor pasid allocation.
> > > 
> > > If we use iommu_sva_alloc_pasid() to allocate a supervisor pasid, which
> > > mm should the pasid be set? I've ever thought about passing &init_mm to
> > > iommu_sva_alloc_pasid(). But if you add "mm != current->mm", this seems
> > > not to work. Or do you prefer a separated interface for supervisor pasid
> > > allocation/free?
> > 
> > Without a mm_struct it is not SVA, so don't use SVA APIs for whatever
> > a 'supervisor pasid' is
> 
> The supervisor PASID has its mm_struct. The only difference is that the
> device will set priv=1 in its DMA transactions with the PASID.

Soemthing like init_mm should not be used with 'SVA'

Jason

  reply	other threads:[~2021-04-15 11:59 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-08 17:08 [PATCH 1/2] iommu/sva: Tighten SVA bind API with explicit flags Jacob Pan
2021-04-08 17:08 ` [PATCH 2/2] iommu/sva: Remove mm parameter from SVA bind API Jacob Pan
2021-04-09 10:11   ` Jean-Philippe Brucker
2021-04-09 18:03     ` Jacob Pan
2021-04-14  0:09       ` Jacob Pan
2021-04-14  6:22         ` Lu Baolu
2021-04-14 11:26           ` Jason Gunthorpe
2021-04-15  5:33             ` Lu Baolu
2021-04-15 11:59               ` Jason Gunthorpe [this message]
2021-04-09 12:45   ` Lu Baolu
2021-04-09 18:08     ` Jacob Pan
2021-04-09 10:22 ` [PATCH 1/2] iommu/sva: Tighten SVA bind API with explicit flags Jean-Philippe Brucker
2021-04-09 21:57   ` Jacob Pan
2021-04-09 12:24 ` Lu Baolu
2021-04-13 22:13   ` Jacob Pan
2021-04-13 13:02 ` kernel test robot
2021-04-14  4:11 ` kernel test robot

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