From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753148AbbDCIlU (ORCPT ); Fri, 3 Apr 2015 04:41:20 -0400 Received: from mx1.redhat.com ([209.132.183.28]:36359 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750747AbbDCIlP (ORCPT ); Fri, 3 Apr 2015 04:41:15 -0400 Date: Fri, 3 Apr 2015 16:40:31 +0800 From: Dave Young To: "Li, Zhen-Hua" Cc: dwmw2@infradead.org, indou.takao@jp.fujitsu.com, bhe@redhat.com, joro@8bytes.org, vgoyal@redhat.com, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, kexec@lists.infradead.org, alex.williamson@redhat.com, ddutile@redhat.com, ishii.hironobu@jp.fujitsu.com, bhelgaas@google.com, doug.hatch@hp.com, jerry.hoemann@hp.com, tom.vaden@hp.com, li.zhang6@hp.com, lisa.mitchell@hp.com, billsumnerlinux@gmail.com, rwright@hp.com Subject: Re: [PATCH v9 0/10] iommu/vt-d: Fix intel vt-d faults in kdump kernel Message-ID: <20150403084031.GF22579@dhcp-128-53.nay.redhat.com> References: <1426743388-26908-1-git-send-email-zhen-hual@hp.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1426743388-26908-1-git-send-email-zhen-hual@hp.com> User-Agent: Mutt/1.5.22.1-rc1 (2013-10-16) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > To fix this problem, we modifies the behaviors of the intel vt-d in the > crashdump kernel: > > For DMA Remapping: > 1. To accept the vt-d hardware in an active state, > 2. Do not disable and re-enable the translation, keep it enabled. > 3. Use the old root entry table, do not rewrite the RTA register. > 4. Malloc and use new context entry table, copy data from the old ones that > used by the old kernel. Have not read all the patches, but I have a question, not sure this has been answered before. Old memory is not reliable, what if the old memory get corrupted before panic? Is it safe to continue using it in 2nd kernel, I worry that it will cause problems. Hope I'm wrong though. Thanks Dave From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mx1.redhat.com ([209.132.183.28]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1YdxA9-0006tT-PX for kexec@lists.infradead.org; Fri, 03 Apr 2015 08:41:14 +0000 Date: Fri, 3 Apr 2015 16:40:31 +0800 From: Dave Young Subject: Re: [PATCH v9 0/10] iommu/vt-d: Fix intel vt-d faults in kdump kernel Message-ID: <20150403084031.GF22579@dhcp-128-53.nay.redhat.com> References: <1426743388-26908-1-git-send-email-zhen-hual@hp.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1426743388-26908-1-git-send-email-zhen-hual@hp.com> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kexec" Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: "Li, Zhen-Hua" Cc: alex.williamson@redhat.com, indou.takao@jp.fujitsu.com, bhe@redhat.com, tom.vaden@hp.com, rwright@hp.com, linux-pci@vger.kernel.org, joro@8bytes.org, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, lisa.mitchell@hp.com, jerry.hoemann@hp.com, iommu@lists.linux-foundation.org, ddutile@redhat.com, doug.hatch@hp.com, ishii.hironobu@jp.fujitsu.com, bhelgaas@google.com, billsumnerlinux@gmail.com, li.zhang6@hp.com, dwmw2@infradead.org, vgoyal@redhat.com > To fix this problem, we modifies the behaviors of the intel vt-d in the > crashdump kernel: > > For DMA Remapping: > 1. To accept the vt-d hardware in an active state, > 2. Do not disable and re-enable the translation, keep it enabled. > 3. Use the old root entry table, do not rewrite the RTA register. > 4. Malloc and use new context entry table, copy data from the old ones that > used by the old kernel. Have not read all the patches, but I have a question, not sure this has been answered before. Old memory is not reliable, what if the old memory get corrupted before panic? Is it safe to continue using it in 2nd kernel, I worry that it will cause problems. Hope I'm wrong though. Thanks Dave _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec