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

From: Nicolin Chen
Date: Thu Mar 16 2023 - 15:51:44 EST


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-shameer
> > > > > 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-6529078da97d@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?

Thanks
Nic