From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3B69DC43381 for ; Wed, 27 Mar 2019 05:36:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 124FA206DF for ; Wed, 27 Mar 2019 05:36:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732061AbfC0Fgp (ORCPT ); Wed, 27 Mar 2019 01:36:45 -0400 Received: from mx1.redhat.com ([209.132.183.28]:36220 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725795AbfC0Fgp (ORCPT ); Wed, 27 Mar 2019 01:36:45 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 163AAC0021CA; Wed, 27 Mar 2019 05:36:45 +0000 (UTC) Received: from localhost.localdomain.com (ovpn-12-53.pek2.redhat.com [10.72.12.53]) by smtp.corp.redhat.com (Postfix) with ESMTP id D7B855C28D; Wed, 27 Mar 2019 05:36:34 +0000 (UTC) From: Lianbo Jiang To: linux-kernel@vger.kernel.org Cc: kexec@lists.infradead.org, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, akpm@linux-foundation.org, x86@kernel.org, hpa@zytor.com, dyoung@redhat.com, bhe@redhat.com, Thomas.Lendacky@amd.com, brijesh.singh@amd.com Subject: [PATCH 0/3 v2] Add kdump support for the SEV enabled guest Date: Wed, 27 Mar 2019 13:36:26 +0800 Message-Id: <20190327053629.17935-1-lijiang@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.31]); Wed, 27 Mar 2019 05:36:45 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Just like the physical machines support kdump, the virtual machines also need kdump. When a virtual machine panic, we also need to dump its memory for analysis. For the SEV virtual machine, the memory is also encrypted. When SEV is enabled, the first kernel is loaded into the encrypted area. Unlike the SME, the first kernel is loaded into the decrypted area. Because of this difference between SME and SEV, we need to properly map the kexec memory area in order to correctly access it. Test tools: makedumpfile[v1.6.5]: git://git.code.sf.net/p/makedumpfile/code commit ("Add support for AMD Secure Memory Encryption") Note: This patch was merged into the devel branch. crash-7.2.5: https://github.com/crash-utility/crash.git commit <942d813cda35> ("Fix for the "kmem -i" option on Linux 5.0") kexec-tools-2.0.19: git://git.kernel.org/pub/scm/utils/kernel/kexec/kexec-tools.git commit <942d813cda35> ("Fix for the kmem '-i' option on Linux 5.0") http://lists.infradead.org/pipermail/kexec/2019-March/022576.html Note: The second kernel cann't boot without this patch. kernel: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git commit ("Merge branch 'akpm' (patches from Andrew)") Test steps: [1] load the vmlinux and initrd for kdump # kexec -p /boot/vmlinuz-5.0.0+ --initrd=/boot/initramfs-5.0.0+kdump.img --command-line="BOOT_IMAGE=(hd0,gpt2)/vmlinuz-5.0.0+ ro resume=UUID=126c5e95-fc8b-48d6-a23b-28409198a52e console=ttyS0,115200 earlyprintk=serial irqpoll nr_cpus=1 reset_devices cgroup_disable=memory mce=off numa=off udev.children-max=2 panic=10 rootflags=nofail acpi_no_memhotplug transparent_hugepage=never disable_cpu_apicid=0" [2] trigger panic # echo 1 > /proc/sys/kernel/sysrq # echo c > /proc/sysrq-trigger [3] check and parse the vmcore # crash vmlinux /var/crash/127.0.0.1-2019-03-15-05\:03\:42/vmcore Changes since v1: 1. Modify the patch subject prefixes. 2. Improve patch log: add parentheses at the end of the function names. 3. Fix the multiple confusing checks. 4. Add comment in the arch_kexec_post_alloc_pages(). Lianbo Jiang (3): x86/kexec: Do not map the kexec area as decrypted when SEV is active x86/kexec: Set the C-bit in the identity map page table when SEV is active kdump,proc/vmcore: Enable kdumping encrypted memory when SEV was active arch/x86/kernel/machine_kexec_64.c | 27 ++++++++++++++++++++++++++- fs/proc/vmcore.c | 6 +++--- 2 files changed, 29 insertions(+), 4 deletions(-) -- 2.17.1