From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from lists.gentoo.org (pigeon.gentoo.org [208.92.234.80]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by finch.gentoo.org (Postfix) with ESMTPS id 2CB03139694 for ; Tue, 16 May 2017 02:34:09 +0000 (UTC) Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id 70415E0D30; Tue, 16 May 2017 02:33:58 +0000 (UTC) Received: from acedia.primate.net (disorder-1-pt.tunnel.tserv3.fmt2.ipv6.he.net [IPv6:2001:470:1f04:51a::2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by pigeon.gentoo.org (Postfix) with ESMTPS id 0B760E0D1C for ; Tue, 16 May 2017 02:33:57 +0000 (UTC) Received: from acedia.primate.net (localhost [127.0.0.1]) by acedia.primate.net (8.15.2/8.15.2/Debian-8) with ESMTPS id v4G2Xut5019341 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT) for ; Mon, 15 May 2017 19:33:56 -0700 Received: (from itz@localhost) by acedia.primate.net (8.15.2/8.15.2/Submit) id v4G2XtUj019335 for gentoo-user@lists.gentoo.org; Mon, 15 May 2017 19:33:55 -0700 X-Authentication-Warning: acedia.primate.net: itz set sender to itz@primate.net using -f Received: from itz by ahiker.mooo.com with local (Exim 4.89) (envelope-from ) id 1dASJ9-00035S-8S for gentoo-user@lists.gentoo.org; Mon, 15 May 2017 19:33:55 -0700 Date: Mon, 15 May 2017 19:33:54 -0700 From: Ian Zimmerman To: gentoo-user@lists.gentoo.org Subject: [gentoo-user] Re: Issues with AMD_IOMMU Message-ID: <20170516014418.2917.244A5940@matica.foolinux.mooo.com> Mail-Followup-To: gentoo-user@lists.gentoo.org References: <5918FF47.6050805@charter.net> <20170515041719.2403.20A7B99C@matica.foolinux.mooo.com> <591A026F.1090508@charter.net> Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-user@lists.gentoo.org Reply-to: gentoo-user@lists.gentoo.org MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <591A026F.1090508@charter.net> User-Agent: Mutt/1.5.24 (2015-08-30) X-Archives-Salt: a9ce35bb-1a67-4388-a3d9-087e7b619ce4 X-Archives-Hash: 02067581bbf3d60a2ac6638d664de673 On 2017-05-15 14:33, Corbin Bird wrote: > Gigabyte has long been known to ship 'broken for Linux' e820 firmware. > 'e820' is basically the APG Aperature setup in the firmware. > Gigabyte kills OR overrides the IOMMU support in the firmware, to setup > the AGP Aperature. > > Closed source / binary video drivers WANT an AGP Aperature. So is _that_ what it's all about? Is the default assumption that I run non-free video drivers? Why? I _never_ use these, and if you bet on me using them in the future and win the bet, you can probably make a cool million or two. > The kernel wants an IOMMU on x86_64, as an IOMMU. But it has one! The GART_IOMMU. It was even added specifically for Linux, according to kernel.org discussions I remember seeing but can't locate now. I also found [1] , which I think is the clearest and most human-oriented explanation of this issue, yet. And ... the recommendation is pretty much the opposite of yours. The ball is in your court, sir. > > CONFIG_X86_X2APIC=y I did this long ago, and it has no effect - still only one is found, according to dmesg. As I wrote in the earlier thread. Also, the Kconfig help for this option says it does something quite different. > > CONFIG_X86_MPPARSE=y Ok, this one I have not set so far. Will read up on it and try, [1] http://bogdan.org.ua/2009/09/30/iommu-this-costs-you-64-mb-of-ram.html -- Please *no* private Cc: on mailing lists and newsgroups Personal signed mail: please _encrypt_ and sign Don't clear-text sign: http://primate.net/~itz/blog/the-problem-with-gpg-signatures.html