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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 01A55C43381 for ; Tue, 12 Mar 2019 10:31:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D07162147C for ; Tue, 12 Mar 2019 10:31:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726860AbfCLKbP (ORCPT ); Tue, 12 Mar 2019 06:31:15 -0400 Received: from mx1.redhat.com ([209.132.183.28]:41404 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725873AbfCLKbO (ORCPT ); Tue, 12 Mar 2019 06:31:14 -0400 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 44BAF3086268; Tue, 12 Mar 2019 10:31:14 +0000 (UTC) Received: from MiWiFi-R3L-srv.redhat.com (ovpn-12-19.pek2.redhat.com [10.72.12.19]) by smtp.corp.redhat.com (Postfix) with ESMTP id 269F31001E63; Tue, 12 Mar 2019 10:31:08 +0000 (UTC) From: Baoquan He To: linux-kernel@vger.kernel.org Cc: kirill.shutemov@linux.intel.com, tglx@linutronix.de, mingo@kernel.org, bp@alien8.de, hpa@zytor.com, dyoung@redhat.com, x86@kernel.org, Baoquan He Subject: [PATCH v3 3/3] x86/kdump/64: Change the upper limit of crashkernel reservation Date: Tue, 12 Mar 2019 18:30:51 +0800 Message-Id: <20190312103051.18086-4-bhe@redhat.com> In-Reply-To: <20190312103051.18086-1-bhe@redhat.com> References: <20190312103051.18086-1-bhe@redhat.com> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.49]); Tue, 12 Mar 2019 10:31:14 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Restrict kdump to only reserve crashkernel below 64TB. Since the kdump jumping may be from 5-level to 4-level, and the kdump kernel is put above 64TB in 5-level kernel, then the jumping will fail. And the crashkernel reservation is done during the 1st kernel bootup, there's no way to detect the paging mode of kdump kernel at that time. Hence change the upper limit of crashkernel reservation to 64TB on x86_64. Signed-off-by: Baoquan He Acked-by: Kirill A. Shutemov --- arch/x86/kernel/setup.c | 18 ++++++++++++++---- 1 file changed, 14 insertions(+), 4 deletions(-) diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index 3d872a527cd9..5508b981f33d 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -451,16 +451,26 @@ static void __init memblock_x86_reserve_range_setup_data(void) #define CRASH_ALIGN (16 << 20) /* - * Keep the crash kernel below this limit. On 32 bits earlier kernels - * would limit the kernel to the low 512 MiB due to mapping restrictions. - * On 64bit, old kexec-tools need to under 896MiB. + * Keep the crash kernel below this limit. + * + * On 32 bits earlier kernels would limit the kernel to the low + * 512 MiB due to mapping restrictions. + * + * On 64bit, old kexec-tools need to be under 896MiB. The later + * supports to put kernel above 4G, up to system RAM top. Here + * kdump kernel need be restricted to be under 64TB, which is + * the upper limit of system RAM in 4-level paing mode. Since + * the kdump jumping could be from 5-level to 4-level, the jumping + * will fail if kernel is put above 64TB, and there's no way to + * detect the paging mode of the kernel which will be loaded for + * dumping during the 1st kernel bootup. */ #ifdef CONFIG_X86_32 # define CRASH_ADDR_LOW_MAX (512 << 20) # define CRASH_ADDR_HIGH_MAX (512 << 20) #else # define CRASH_ADDR_LOW_MAX (896UL << 20) -# define CRASH_ADDR_HIGH_MAX MAXMEM +# define CRASH_ADDR_HIGH_MAX (64UL << 40) #endif static int __init reserve_crashkernel_low(void) -- 2.17.2