RE: [PATCH v10 1/6] iommu: Change kconfig around IOMMU_SVA

[Zhang, Tina]

Hi Joerg,

> -----Original Message-----
> From: Joerg Roedel <joro@xxxxxxxxxx>
> Sent: Friday, October 27, 2023 3:12 PM
> To: Zhang, Tina <tina.zhang@xxxxxxxxx>
> Cc: iommu@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; David Woodhouse
> <dwmw2@xxxxxxxxxxxxx>; Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>; Will Deacon
> <will@xxxxxxxxxx>; Robin Murphy <robin.murphy@xxxxxxx>; Jason
> Gunthorpe <jgg@xxxxxxxx>; Tian, Kevin <kevin.tian@xxxxxxxxx>; Nicolin Chen
> <nicolinc@xxxxxxxxxx>; Michael Shavit <mshavit@xxxxxxxxxx>; Vasant
> Hegde <vasant.hegde@xxxxxxx>; Jason Gunthorpe <jgg@xxxxxxxxxx>
> Subject: Re: [PATCH v10 1/6] iommu: Change kconfig around IOMMU_SVA
> 
> Hi Tina,
> 
> On Fri, Oct 27, 2023 at 08:05:20AM +0800, Tina Zhang wrote:
> > From: Jason Gunthorpe <jgg@xxxxxxxxxx>
> >
> > 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.
Make sense. I'll CC Linus. Comments are welcome.

> >
> > https://lore.kernel.org/all/CAHk-
> =wgUiAtiszwseM1p2fCJ+sC4XWQ+YN4TanFhU
> > gvUqjr9Xw@xxxxxxxxxxxxxx/
> >
> > 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@xxxxxxxxxx>
> 
> If you send it, you also need to add your Signed-off-by.
OK. I'll add my Signed-off-by.

Thanks,
-Tina

> 
> Regards,
> 
> 	Joerg