linux-kernel - Re: [PATCH v4 09/13] iommu/arm-smmu-v3: Implement set_dev

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: <CAKHBV266J1S6EMMjNCRMPhSXCKnqU7-H=rhi5iMbV4D9rH7WgQ@mail.gmail.com>
Date:   Mon, 26 Jun 2023 10:33:58 +0800
From:   Michael Shavit <mshavit@...gle.com>
To:     Nicolin Chen <nicolinc@...dia.com>
Cc:     Will Deacon <will@...nel.org>, Robin Murphy <robin.murphy@....com>,
        Joerg Roedel <joro@...tes.org>, jean-philippe@...aro.org,
        jgg@...dia.com, baolu.lu@...ux.intel.com,
        linux-arm-kernel@...ts.infradead.org, iommu@...ts.linux.dev,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v4 09/13] iommu/arm-smmu-v3: Implement set_dev_pasid

> Would you please elaborate a bit more for the use case of
allowing that?

In short; to support devices that use SSID to isolate different
(device) contexts. Those contexts (and the memory available to them)
is partially managed by the device's Kernel driver.

> And which test configuration do you cover
using smmute? Would you mind sharing your test commands?

I used the setup suggested by Jean in
https://lore.kernel.org/all/20230511195928.GA288490@myrica/ , with the
following commands:
>>>
# Basic test
./smmute;
./smmute -u mmap;

# Test invalid access to not-mapped address
./smmute -u mmap -f drv;

# Test invalid access after unmap
./smmute -u mmap -f write -d;

# Check smmu_mn released when killed
mount -t tracefs nodev /sys/kernel/tracing;
echo 1 > /sys/kernel/tracing/events/iommu/enable;
echo 1 > /sys/kernel/tracing/events/smmu/enable;
./smmute -u mmap -k bind;
cat /sys/kernel/tracing/trace;
<<<

This only covers existing SVA functionality. To test the functionality
introduced by this patch, I used a device capable of generating DMA
transactions w/ SSID and a test driver with following tests:
1. Successful dma Read/Write to buffer mapped on domain attached with pasid
2. Unsuccessful dma Read/Write to same buffer after domain detached
from pasid, or after buffer unmapped from domain
3. Variations of the above with a domain attached to multiple pasids

I've been considering migrating those tests to the smmute driver if
that would be valuable.



On Fri, Jun 23, 2023 at 8:32 AM Nicolin Chen <nicolinc@...dia.com> wrote:
>
> Hi Michael,
>
> On Wed, Jun 21, 2023 at 02:37:21PM +0800, Michael Shavit wrote:
> >
> > This change enables the use of the iommu_attach_dev_pasid API for
> > UNMANAGED domains. The primary use-case is to allow in-kernel users of
> > the iommu API to manage domains with PASID. This change also allows for
> > future support of pasid in the DMA api.
>
> Would you please elaborate a bit more for the use case of
> allowing that? And which test configuration do you cover
> using smmute? Would you mind sharing your test commands?
>
> I have run a sanity with this series using an SVA domain
> with a real master. It seems to be fine.
>
> Thanks
> Nicolin