From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933906AbeD0PMa (ORCPT ); Fri, 27 Apr 2018 11:12:30 -0400 Received: from terminus.zytor.com ([198.137.202.136]:53515 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933750AbeD0PMQ (ORCPT ); Fri, 27 Apr 2018 11:12:16 -0400 Date: Fri, 27 Apr 2018 08:09:44 -0700 From: tip-bot for Petr Tesarik Message-ID: Cc: ptesarik@suse.cz, thomas.lendacky@amd.com, boris.ostrovsky@oracle.com, mpatocka@redhat.com, tglx@linutronix.de, jgross@suse.com, luto@kernel.org, ptesarik@suse.com, linux-kernel@vger.kernel.org, douly.fnst@cn.fujitsu.com, mingo@kernel.org, jdelvare@suse.de, hpa@zytor.com, bp@suse.de Reply-To: ptesarik@suse.com, linux-kernel@vger.kernel.org, douly.fnst@cn.fujitsu.com, mingo@kernel.org, jdelvare@suse.de, hpa@zytor.com, bp@suse.de, thomas.lendacky@amd.com, ptesarik@suse.cz, boris.ostrovsky@oracle.com, mpatocka@redhat.com, tglx@linutronix.de, jgross@suse.com, luto@kernel.org In-Reply-To: <20180425120835.23cef60c@ezekiel.suse.cz> References: <20180425120835.23cef60c@ezekiel.suse.cz> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/urgent] x86/setup: Do not reserve a crash kernel region if booted on Xen PV Git-Commit-ID: 3db3eb285259ac129f7aec6b814b3e9f6c1b372b X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 3db3eb285259ac129f7aec6b814b3e9f6c1b372b Gitweb: https://git.kernel.org/tip/3db3eb285259ac129f7aec6b814b3e9f6c1b372b Author: Petr Tesarik AuthorDate: Wed, 25 Apr 2018 12:08:35 +0200 Committer: Thomas Gleixner CommitDate: Fri, 27 Apr 2018 17:06:28 +0200 x86/setup: Do not reserve a crash kernel region if booted on Xen PV Xen PV domains cannot shut down and start a crash kernel. Instead, the crashing kernel makes a SCHEDOP_shutdown hypercall with the reason code SHUTDOWN_crash, cf. xen_crash_shutdown() machine op in arch/x86/xen/enlighten_pv.c. A crash kernel reservation is merely a waste of RAM in this case. It may also confuse users of kexec_load(2) and/or kexec_file_load(2). When flags include KEXEC_ON_CRASH or KEXEC_FILE_ON_CRASH, respectively, these syscalls return success, which is technically correct, but the crash kexec image will never be actually used. Signed-off-by: Petr Tesarik Signed-off-by: Thomas Gleixner Reviewed-by: Juergen Gross Cc: Tom Lendacky Cc: Dou Liyang Cc: Mikulas Patocka Cc: Andy Lutomirski Cc: "H. Peter Anvin" Cc: xen-devel@lists.xenproject.org Cc: Boris Ostrovsky Cc: Borislav Petkov Cc: Jean Delvare Link: https://lkml.kernel.org/r/20180425120835.23cef60c@ezekiel.suse.cz --- arch/x86/kernel/setup.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index 6285697b6e56..5c623dfe39d1 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -50,6 +50,7 @@ #include #include #include +#include #include #include @@ -534,6 +535,11 @@ static void __init reserve_crashkernel(void) high = true; } + if (xen_pv_domain()) { + pr_info("Ignoring crashkernel for a Xen PV domain\n"); + return; + } + /* 0 means: find the address automatically */ if (crash_base <= 0) { /*