Date: Mon, 6 Mar 2023 16:45:49 -0800
From: Jacob Pan <jacob.jun.pan@linux.intel.com>
To: Jason Gunthorpe <jgg@nvidia.com>
Cc: "Tian, Kevin" <kevin.tian@intel.com>, Baolu Lu
 <baolu.lu@linux.intel.com>, LKML <linux-kernel@vger.kernel.org>,
 "iommu@lists.linux.dev" <iommu@lists.linux.dev>, Joerg Roedel
 <joro@8bytes.org>, "dmaengine@vger.kernel.org" <dmaengine@vger.kernel.org>,
 "vkoul@kernel.org" <vkoul@kernel.org>, Robin Murphy <robin.murphy@arm.com>,
 Will Deacon <will@kernel.org>, David Woodhouse <dwmw2@infradead.org>, "Raj,
 Ashok" <ashok.raj@intel.com>, "Liu, Yi L" <yi.l.liu@intel.com>, "Yu,
 Fenghua" <fenghua.yu@intel.com>, "Jiang, Dave" <dave.jiang@intel.com>,
 "Luck, Tony" <tony.luck@intel.com>, "Zanussi, Tom" <tom.zanussi@intel.com>,
 jacob.jun.pan@linux.intel.com
Subject: Re: [PATCH 1/4] iommu/vt-d: Implement set device pasid op for
 default domain
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In-Reply-To: <20230306154504.04769726@jacob-builder>
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Hi Jacob,

On Mon, 6 Mar 2023 15:45:04 -0800, Jacob Pan
<jacob.jun.pan@linux.intel.com> wrote:

> Hi Jason,
> 
> On Mon, 6 Mar 2023 15:02:37 -0400, Jason Gunthorpe <jgg@nvidia.com> wrote:
> 
> > On Mon, Mar 06, 2023 at 11:04:43AM -0800, Jacob Pan wrote:
> >   
> > > > and probably this is the right thing to do as in the end DMA type
> > > > will be removed with Jason's cleanup    
> > >
> > > so, let me recap. set_dev_pasid() should make no assumptions of
> > > ordering, i.e. it is equal to iommu_domain_ops.attach_dev().    
> > 
> > Absolutely yes.
> > 
> > You should factor out all the "prepare the domain to be used" code and
> > call it in both places.
> >   
> I think this has been done by Baolu
> https://lore.kernel.org/linux-iommu/20190325013036.18400-1-baolu.lu@linux.intel.com/T/#m8c980357a39dc75dc360ff0f71dc7ebe1e49f9a6
> iommu/vt-d: Move common code out of iommu_attch_device()
>     
>     This part of code could be used by both normal and aux
>     domain specific attach entries. Hence move them into a
>     common function to avoid duplication.
> 
> set_dev_pasid() will call prepare_domain_attach_device() as well.
Actually, there are more to be factored to common code if we take that
assumption away. attach_dev() can be viewed as a special case for
set_dev_pasid() except the PASID is RID_PASID.

Thanks,

Jacob