From: Nicolin Chen <nicolinc@nvidia.com>
To: Jason Gunthorpe <jgg@nvidia.com>
Cc: Robin Murphy <robin.murphy@arm.com>,
Will Deacon <will@kernel.org>,
"Joerg Roedel (AMD)" <joro@8bytes.org>,
<linux-tegra@vger.kernel.org>,
<linux-arm-kernel@lists.infradead.org>, <iommu@lists.linux.dev>,
<linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v3] iommu/tegra241-cmdqv: Reject a VCMDQ base above the 48-bit hardware limit
Date: Thu, 6 Aug 2026 10:22:26 -0700 [thread overview]
Message-ID: <anTC0q50E9Kp2zFC@nvidia.com> (raw)
In-Reply-To: <20260806140951.GA71449@nvidia.com>
On Thu, Aug 06, 2026 at 11:09:51AM -0300, Jason Gunthorpe wrote:
> On Thu, Aug 06, 2026 at 02:17:31PM +0100, Robin Murphy wrote:
>
> > But if we really do want to bother sanity-checking emulations, then why
> > allow them to still get away with being broken in the case that we do happen
> > to allocate queue memory at a sufficiently low PA anyway? Why not actually
> > validate smmu->oas itself (plus anything else relevant) in
> > __tegra241_cmdqv_probe()?
>
> Yeah, if the VMM has setup the SMMU so it cannot access all of DRAM
> then it is going to be really broken across the entire driver. This
> just doesn't work at all. No reason to add any special cases to look
> for it only in vcmdq.
It sounds that a rejection in __tegra241_cmdqv_probe() wouldn't be
necessary either.
Let's drop the patch then.
Thanks
Nicolin
prev parent reply other threads:[~2026-08-06 17:23 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-29 22:03 [PATCH v3] iommu/tegra241-cmdqv: Reject a VCMDQ base above the 48-bit hardware limit Nicolin Chen
2026-08-06 12:47 ` Will Deacon
2026-08-06 13:17 ` Robin Murphy
2026-08-06 14:09 ` Jason Gunthorpe
2026-08-06 17:22 ` Nicolin Chen [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=anTC0q50E9Kp2zFC@nvidia.com \
--to=nicolinc@nvidia.com \
--cc=iommu@lists.linux.dev \
--cc=jgg@nvidia.com \
--cc=joro@8bytes.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-tegra@vger.kernel.org \
--cc=robin.murphy@arm.com \
--cc=will@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox