RE: [PATCH v1 01/14] iommu: Add iommu_get_unmanaged_domain helper

[Shameerali Kolothum Thodi]

> -----Original Message-----
> From: Nicolin Chen [mailto:nicolinc@xxxxxxxxxx]
> Sent: 16 March 2023 19:51
> To: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@xxxxxxxxxx>;
> Eric Auger <eric.auger@xxxxxxxxxx>
> Cc: Jason Gunthorpe <jgg@xxxxxxxxxx>; robin.murphy@xxxxxxx;
> will@xxxxxxxxxx; kevin.tian@xxxxxxxxx; baolu.lu@xxxxxxxxxxxxxxx;
> joro@xxxxxxxxxx; jean-philippe@xxxxxxxxxx;
> linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; iommu@xxxxxxxxxxxxxxx;
> linux-kernel@xxxxxxxxxxxxxxx
> Subject: Re: [PATCH v1 01/14] iommu: Add iommu_get_unmanaged_domain
> helper
> 
> Hi Shameer/Eric,
> 
> On Fri, Mar 10, 2023 at 04:30:03PM +0000, Shameerali Kolothum Thodi
> wrote:
> > External email: Use caution opening links or attachments
> >
> >
> > > -----Original Message-----
> > > From: Jason Gunthorpe [mailto:jgg@xxxxxxxxxx]
> > > Sent: 10 March 2023 16:21
> > > To: Shameerali Kolothum Thodi
> <shameerali.kolothum.thodi@xxxxxxxxxx>
> > > Cc: Eric Auger <eric.auger@xxxxxxxxxx>; Nicolin Chen
> > > <nicolinc@xxxxxxxxxx>; robin.murphy@xxxxxxx; will@xxxxxxxxxx;
> > > kevin.tian@xxxxxxxxx; baolu.lu@xxxxxxxxxxxxxxx; joro@xxxxxxxxxx;
> > > jean-philippe@xxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx;
> > > iommu@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
> > > Subject: Re: [PATCH v1 01/14] iommu: Add
> iommu_get_unmanaged_domain
> > > helper
> > >
> > > On Fri, Mar 10, 2023 at 04:07:38PM +0000, Shameerali Kolothum Thodi
> > > wrote:
> > > > >
> > >
> https://lore.kernel.org/linux-arm-kernel/20220420164836.1181-5-shame
> > > er
> > > > > > ali.kolothum.thodi@xxxxxxxxxx/
> > > > >
> > > > > So "boot configration" is more like "don't change the RIDs"? Ie
> > > > > don't
> > > enable
> > > > > SRIOV?
> > > >
> > > > Yes. Don't think it will work with SR-IOV if you can't guarantee
> > > > the RMR
> > > specified
> > > > SID.
> > >
> > > So I think we are probably good them because vSR-IOV is already not
> > > supported by qemu, so it impossible for a VM to change the PCI
> > > configuration in a way that would alter the RID to SID mapping?
> > >
> >
> > Provided we fix the issue mentioned by Eric. This was discussed here
> > previously,
> >
> > https://lore.kernel.org/linux-arm-kernel/bb3688c7-8f42-039e-e22f-65290
> > 78da97d@xxxxxxxxxx/
> 
> Have we fixed the issue? I saw Lorenzo replying in that thread:
> https://lore.kernel.org/linux-arm-kernel/Yi8nV8H4Jjlpadmk@lpieralisi/
> 
> Or, what's remaining here regarding this topic? Is it a blocker?

[+Lorenzo]

Not sure it is fixed yet. Also, assuming we take RMR path, do we plan to support 
DT base Guests at all?

Thanks,
Shameer