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Date:   Fri, 27 Oct 2023 09:12:04 +0200
From:   Joerg Roedel <joro@8bytes.org>
To:     Tina Zhang <tina.zhang@intel.com>
Cc:     iommu@lists.linux.dev, linux-kernel@vger.kernel.org,
        David Woodhouse <dwmw2@infradead.org>,
        Lu Baolu <baolu.lu@linux.intel.com>,
        Will Deacon <will@kernel.org>,
        Robin Murphy <robin.murphy@arm.com>,
        Jason Gunthorpe <jgg@ziepe.ca>,
        Kevin Tian <kevin.tian@intel.com>,
        Nicolin Chen <nicolinc@nvidia.com>,
        Michael Shavit <mshavit@google.com>,
        Vasant Hegde <vasant.hegde@amd.com>,
        Jason Gunthorpe <jgg@nvidia.com>
Subject: Re: [PATCH v10 1/6] iommu: Change kconfig around IOMMU_SVA
Message-ID: <ZTtixEgSkBI-TRro@8bytes.org>
References: <20231027000525.1278806-1-tina.zhang@intel.com>
 <20231027000525.1278806-2-tina.zhang@intel.com>
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Hi Tina,

On Fri, Oct 27, 2023 at 08:05:20AM +0800, Tina Zhang wrote:
> From: Jason Gunthorpe <jgg@nvidia.com>
> 
> Linus suggested that the kconfig here is confusing:

While this patch looks decent to me, you forgot to Cc Linus on it. In
general, given that it touches a couple of core files, I'd like to wait
for some more people to have a look at it and not rushing anything in.
> 
> https://lore.kernel.org/all/CAHk-=wgUiAtiszwseM1p2fCJ+sC4XWQ+YN4TanFhUgvUqjr9Xw@mail.gmail.com/
> 
> Let's break it into three kconfigs controlling distinct things:
> 
>  - CONFIG_IOMMU_MM_DATA controls if the mm_struct has the additional
>    fields for the IOMMU. Currently only PASID, but later patches store
>    a struct iommu_mm_data *
> 
>  - CONFIG_ARCH_HAS_CPU_PASID controls if the arch needs the scheduling bit
>    for keeping track of the ENQCMD instruction. x86 will select this if
>    IOMMU_SVA is enabled
> 
>  - IOMMU_SVA controls if the IOMMU core compiles in the SVA support code
>    for iommu driver use and the IOMMU exported API
> 
> This way ARM will not enable CONFIG_ARCH_HAS_CPU_PASID
> 
> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

If you send it, you also need to add your Signed-off-by.

Regards,

	Joerg