linux-kernel - Re: [PATCH v2] iommu/amd: Disable IOMMU on Stoney Ridge systems

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: <20191202170011.GC30032@infradead.org>
Date:   Mon, 2 Dec 2019 09:00:11 -0800
From:   Christoph Hellwig <hch@...radead.org>
To:     Kai-Heng Feng <kai.heng.feng@...onical.com>
Cc:     joro@...tes.org, Alex Deucher <alexander.deucher@....com>,
        iommu@...ts.linux-foundation.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2] iommu/amd: Disable IOMMU on Stoney Ridge systems

On Fri, Nov 29, 2019 at 10:21:54PM +0800, Kai-Heng Feng wrote:
> Serious screen flickering when Stoney Ridge outputs to a 4K monitor.
> 
> According to Alex Deucher, IOMMU isn't enabled on Windows, so let's do
> the same here to avoid screen flickering on 4K monitor.

Disabling the IOMMU entirely seem pretty severe.  Isn't it enough to
identity map the GPU device?