linux-kernel - Re: [PATCH v2] dmaengine: rcar-dmac: don't use DMAC error interrupt

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: <87o9gcsxj3.wl%kuninori.morimoto.gx@renesas.com>
Date:   Fri, 15 Jun 2018 00:33:12 +0000
From:   Kuninori Morimoto <kuninori.morimoto.gx@...esas.com>
To:     Geert Uytterhoeven <geert@...ux-m68k.org>
Cc:     <vkoul@...nel.org>, Dan Williams <dan.j.williams@...el.com>,
        Magnus Damm <magnus.damm@...il.com>,
        Linux-Renesas <linux-renesas-soc@...r.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        Laurent Pinchart <laurent.pinchart@...asonboard.com>,
        Kieran Bingham <kieran@...uared.org.uk>,
        Geert Uytterhoeven <geert+renesas@...der.be>,
        <dmaengine@...r.kernel.org>,
        "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" 
        <devicetree@...r.kernel.org>
Subject: Re: [PATCH v2] dmaengine: rcar-dmac: don't use DMAC error interrupt


Hi Geert

Thank you for your feedback

> > Current rcar-dmac is using DMAC error interrupt which will handle all
> > channel's error. But in this design, error handling itself will be
> > issue if user want to use virtualization, multi OS, etc.
> > This patch removes current DMAC error interrupt handling, and handle it
> > on each channel interrupt handler.
> 
> Just wondering, what's the usage pattern where this causes a problem?
> Do you plan to export part of a SYS-DMAC instance to a guest?

"virtualization, multi OS" part is maybe misleading.
It will be problem on non virtualization, too.

> How to maintain host/guest isolation?

This is another topic/issue, I think

Best regards
---
Kuninori Morimoto