linux-kernel - Re: [PATCH v2 14/18] iommu/arm-smmu-v3: Support domains with shared CDs

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <ZKw38RrJ0FG8zbqt@nvidia.com>
Date:   Mon, 10 Jul 2023 13:55:13 -0300
From:   Jason Gunthorpe <jgg@...dia.com>
To:     "Zhang, Tina" <tina.zhang@...el.com>
Cc:     Michael Shavit <mshavit@...gle.com>, Will Deacon <will@...nel.org>,
        Robin Murphy <robin.murphy@....com>,
        Joerg Roedel <joro@...tes.org>,
        "jean-philippe@...aro.org" <jean-philippe@...aro.org>,
        "nicolinc@...dia.com" <nicolinc@...dia.com>,
        "baolu.lu@...ux.intel.com" <baolu.lu@...ux.intel.com>,
        "linux-arm-kernel@...ts.infradead.org" 
        <linux-arm-kernel@...ts.infradead.org>,
        "iommu@...ts.linux.dev" <iommu@...ts.linux.dev>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v2 14/18] iommu/arm-smmu-v3: Support domains with shared
 CDs

On Wed, Jul 05, 2023 at 09:56:50AM +0000, Zhang, Tina wrote:

> > Possibly what we should do is conver the u32 pasid in the mm_struct to a
> > struct iommu_mm_data * and put alot more stuff in there. eg a linked list of
> > all SVA domains.

> If we are going to have 1:1 between SVA domain and pasid, why we
> need a linked list of all SVA domains? Would a SVA domain pointer be
> enough?

Kevin asked this, we can't assume that a single SVA domain is going to
work in a multi-iommu-driver system, which we are trying to enable at
the core level..
 
> I've got a patch-set which takes this suggestion to add an
> iommu_mm_data struct field to mm_struct. I'll send it out for review
> soon. The motivation of that patch-set is to let the
> invalidate_range() callback use the SVA domain referenced by
> mm->iommu_mm_data->sva_domain to do per-iommu IOTLB invalidation.

Huh?

You are supposed to put the struct mmu_notifier inside the sva_domain
struct and use container_of().

This is another reason why I'd prefer we de-duplicate SVA domains at
the core code level as duplicitive notifiers are expensive..

Please don't add stuff to the mm just for this reason.

Jason