From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Woodhouse Subject: Re: [PATCH 00/19] Fix Intel IOMMU breakage in kdump kernel Date: Thu, 25 Jun 2015 09:06:40 +0100 Message-ID: <1435219600.8688.7.camel@infradead.org> References: <1434178047-17809-1-git-send-email-joro@8bytes.org> <1435066290.12045.2.camel@infradead.org> <20150623140631.GB2724@suse.de> <1435070334.12045.24.camel@infradead.org> <558BA149.5060603@hp.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <558BA149.5060603@hp.com> Sender: linux-kernel-owner@vger.kernel.org To: "Li, ZhenHua" Cc: Joerg Roedel , Joerg Roedel , iommu@lists.linux-foundation.org, bhe@redhat.com, ddutile@redhat.com, alex.williamson@redhat.com, dyoung@redhat.com, linux-kernel@vger.kernel.org, jroedel@8bytes.org List-Id: iommu@lists.linux-foundation.org On Thu, 2015-06-25 at 14:35 +0800, Li, ZhenHua wrote: > Hi David, > It is a bad idea to check the DMI match on "HP". Though I have not se= e > any similar problems on other systems, I believe there are. Also not > all HP systems have such problem. Yeah, the HP suggestion was a little tongue-in-cheek. Although it does seem to be HP who is the main offender in this area =E2=80=94 both the = BIOS "value subtract" and the habit of doing utterly insane things with the IOMMU. > I agree with a blacklist for devices. Do you have a list of the problematic ones? I think a blacklist *and* an option to enable it for all devices might be the best solution. --=20 dwmw2