Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755786Ab0DCRtT (ORCPT ); Sat, 3 Apr 2010 13:49:19 -0400 Received: from out01.mta.xmission.com ([166.70.13.231]:38289 "EHLO out01.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755075Ab0DCRtN (ORCPT ); Sat, 3 Apr 2010 13:49:13 -0400 To: Joerg Roedel Cc: Chris Wright , Joerg Roedel , nhorman@redhat.com, nhorman@tuxdriver.com, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, hbabu@us.ibm.com, iommu@lists.linux-foundation.org, vgoyal@redhat.com Subject: Re: [PATCH 3/4] Revert "x86: disable IOMMUs on kernel crash" References: <20100403012751.834020949@sous-sol.org> <20100403012820.229410717@sous-sol.org> <20100403174128.GQ24846@8bytes.org> From: ebiederm@xmission.com (Eric W. Biederman) Date: Sat, 03 Apr 2010 10:49:09 -0700 In-Reply-To: <20100403174128.GQ24846@8bytes.org> (Joerg Roedel's message of "Sat\, 3 Apr 2010 19\:41\:28 +0200") Message-ID: User-Agent: Gnus/5.11 (Gnus v5.11) Emacs/22.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-XM-SPF: eid=;;;mid=;;;hst=in02.mta.xmission.com;;;ip=76.21.114.89;;;frm=ebiederm@xmission.com;;;spf=neutral X-SA-Exim-Connect-IP: 76.21.114.89 X-SA-Exim-Rcpt-To: joro@8bytes.org, vgoyal@redhat.com, iommu@lists.linux-foundation.org, hbabu@us.ibm.com, linux-kernel@vger.kernel.org, kexec@lists.infradead.org, nhorman@tuxdriver.com, nhorman@redhat.com, joerg.roedel@amd.com, chrisw@sous-sol.org X-SA-Exim-Mail-From: ebiederm@xmission.com X-SA-Exim-Scanned: No (on in02.mta.xmission.com); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1675 Lines: 51 Joerg Roedel writes: > On Fri, Apr 02, 2010 at 06:27:54PM -0700, Chris Wright wrote: >> This effectively reverts commit 61d047be99757fd9b0af900d7abce9a13a337488. >> >> Disabling the IOMMU can potetially allow DMA transactions to >> complete without being translated. Leave it enabled, and allow >> crash kernel to do the IOMMU reinitialization properly. >> >> Cc: Joerg Roedel >> Cc: Eric Biederman >> Cc: Neil Horman >> Cc: Vivek Goyal >> Signed-off-by: Chris Wright >> --- >> arch/x86/kernel/crash.c | 6 ------ >> 1 file changed, 6 deletions(-) >> >> --- a/arch/x86/kernel/crash.c >> +++ b/arch/x86/kernel/crash.c >> @@ -27,7 +27,6 @@ >> #include >> #include >> #include >> -#include >> >> #if defined(CONFIG_SMP) && defined(CONFIG_X86_LOCAL_APIC) >> >> @@ -103,10 +102,5 @@ void native_machine_crash_shutdown(struc >> #ifdef CONFIG_HPET_TIMER >> hpet_disable(); >> #endif >> - >> -#ifdef CONFIG_X86_64 >> - x86_platform.iommu_shutdown(); >> -#endif >> - >> crash_save_cpu(regs, safe_smp_processor_id()); > > Another problem: This also breaks if the kdump kernel has no > iommu-support. Not a problem. We require a lot of things of the kdump kernel, and it is immediately apparent in a basic sanity test. Eric -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/