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From: Mikko Perttunen <cyndis@kapsi.fi>
To: Dmitry Osipenko <digetx@gmail.com>,
	Thierry Reding <thierry.reding@gmail.com>,
	Jonathan Hunter <jonathanh@nvidia.com>,
	Peter De Schrijver <pdeschrijver@nvidia.com>
Cc: linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [RFC PATCH v1] memory: tegra: Block DMA for clients HW on a faulty memory access
Date: Sun, 5 Aug 2018 03:11:57 +0300	[thread overview]
Message-ID: <89f0794e-affa-dba0-9684-582ce5570cad@kapsi.fi> (raw)
In-Reply-To: <2607799.I2xByD6lqT@dimapc>

One potential issue is with host1x clients where userspace processes can 
submit jobs with invalid memory accesses (addresses not mapped to 
IOMMU). If when such a failure happens, we disable the DMA for the whole 
host1x client, unrelated userspace processes may see failures even 
though there is no problem with their jobs.

Mikko

On 08/04/2018 02:53 PM, Dmitry Osipenko wrote:
> On Tuesday, 8 May 2018 19:58:41 MSK Dmitry Osipenko wrote:
>> Currently Memory Controller informs about erroneous memory accesses done
>> by memory clients and that's it. Let's make it to block whole HW unit
>> that corresponds to the misbehaving memory client in order to try to avoid
>> memory corruptions and to stop deliberate attempts of manipulation by a
>> misbehaving client.
> 
> Guys, any comments? That is a kinda useful feature, in worst case only some of
> memory could get corrupted instead of trashing the whole memory. In my
> experience with T20/30, the interrupt handling latency is low and blocking
> happens immediately after the first page fault.
> 
> 
> 

  reply	other threads:[~2018-08-05  0:12 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-05-08 16:58 Dmitry Osipenko
2018-08-04 11:53 ` Dmitry Osipenko
2018-08-05  0:11   ` Mikko Perttunen [this message]
2018-08-05  0:37     ` Dmitry Osipenko

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