From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58221) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZZZTE-0008Ah-LY for qemu-devel@nongnu.org; Wed, 09 Sep 2015 03:07:05 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZZZTD-0002A6-7J for qemu-devel@nongnu.org; Wed, 09 Sep 2015 03:07:04 -0400 Received: from mail-lb0-x22f.google.com ([2a00:1450:4010:c04::22f]:35121) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZZZTD-00029P-0R for qemu-devel@nongnu.org; Wed, 09 Sep 2015 03:07:03 -0400 Received: by lbpo4 with SMTP id o4so564464lbp.2 for ; Wed, 09 Sep 2015 00:07:02 -0700 (PDT) References: <55EF5493.5090600@web.de> <55EFD5EB.9090700@gmail.com> From: Valentine Sinitsyn Message-ID: <55EFDA94.3060405@gmail.com> Date: Wed, 9 Sep 2015 12:07:00 +0500 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] Aspirant for AMD IOMMU emulation project for Outreachy List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: David kiarie Cc: Peter Maydell , Rita Sinha , Jan Kiszka , QEMU Developers On 09.09.2015 11:54, David kiarie wrote: ...snip... >>> Most recent work is here >>> http://lists.nongnu.org/archive/html/qemu-devel/2015-08/msg02759.html >>> . Most the code is Qemu device boilerplate(so there are a ton of >>> things to add but I wanted to have the existing work merged first). >>> The IOMMU just offers basic translation. From Valentine's previous >>> comments, I only have a few minor issues to fix in the code. >> >> This is a bit of off-topic here, but I'd argue they are minor. There are >> some inaccuracies in emulation, and IOMMU itself is rather feature-limited, >> just as you said. I doubt I'd be able to run current Jailhouse >> implementation on it, for instance, albeit I haven't tried. So, your patches >> are good start, but I feel there's a somewhat long way before they actually >> get merged. > > Yep, that is possible. For instance, you were insisting on 'cache' > implemention ;) which IMHO, is optional but could be a good project > start. The thing that worried me most is how you handle invalid Device Table entries, and that most bits in control/status registers are actually no-op. And I don't insist on cache implementation, just make sure there is a way to invalidate the configuration. Maybe I overlooked something and you already do it? Let's discuss it not in this thread but where your patch is. > >> >> So, in short: there are still tasks to be done in AMD IOMMU emulation >> project. I also feel it's possible to parallelize them so David and Rita can >> continue without stepping at each other toe, if the program permits it. >> >>> I obviously do other things alongside :-D this project but given some >>> time I could get the code merged and continue to add other features. >>> >>>> >>>> For the Outreachy program, just like for GSoC, we need to find a good >>>> topic that is sufficiently clear defined on program start and not worked >>>> on in parallel during the runtime. There are still a number of open >>>> topics in this area, e.g. around the older Intel IOMMU model (error >>>> handling and reporting, interrupt remapping), or maybe we find something >>>> different - depends on your interests and experiences. Do you have any >>>> public references to your previous work? >>>> >>>> Then I'd suggest to schedule an irc meeting to discuss your interests >>>> and background a bit further and consider available options. >>>> >>>> Jan >>>> >> >> Regards, >> Valentine Valentine