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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 27C94C4332F for ; Mon, 1 Nov 2021 21:12:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0670060184 for ; Mon, 1 Nov 2021 21:12:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231205AbhKAVO7 (ORCPT ); Mon, 1 Nov 2021 17:14:59 -0400 Received: from out02.mta.xmission.com ([166.70.13.232]:38738 "EHLO out02.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229501AbhKAVOy (ORCPT ); Mon, 1 Nov 2021 17:14:54 -0400 Received: from in01.mta.xmission.com ([166.70.13.51]:44908) by out02.mta.xmission.com with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1mhebJ-0082VH-1q; Mon, 01 Nov 2021 15:12:17 -0600 Received: from ip68-227-160-95.om.om.cox.net ([68.227.160.95]:34474 helo=email.xmission.com) by in01.mta.xmission.com with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1mhebH-002zh6-PG; Mon, 01 Nov 2021 15:12:16 -0600 From: ebiederm@xmission.com (Eric W. Biederman) To: Borislav Petkov Cc: Joerg Roedel , x86@kernel.org, kexec@lists.infradead.org, Joerg Roedel , stable@vger.kernel.org, hpa@zytor.com, Andy Lutomirski , Dave Hansen , Peter Zijlstra , Jiri Slaby , Dan Williams , Tom Lendacky , Juergen Gross , Kees Cook , David Rientjes , Cfir Cohen , Erdem Aktas , Masami Hiramatsu , Mike Stunes , Sean Christopherson , Martin Radev , Arvind Sankar , linux-coco@lists.linux.dev, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, virtualization@lists.linux-foundation.org References: <20210913155603.28383-1-joro@8bytes.org> <20210913155603.28383-2-joro@8bytes.org> Date: Mon, 01 Nov 2021 16:11:42 -0500 In-Reply-To: (Borislav Petkov's message of "Mon, 1 Nov 2021 17:10:25 +0100") Message-ID: <87pmrjbmy9.fsf@disp2133> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-XM-SPF: eid=1mhebH-002zh6-PG;;;mid=<87pmrjbmy9.fsf@disp2133>;;;hst=in01.mta.xmission.com;;;ip=68.227.160.95;;;frm=ebiederm@xmission.com;;;spf=neutral X-XM-AID: U2FsdGVkX1/dOcje8rMk6fFebgEu/saSTasGNFo4jXQ= X-SA-Exim-Connect-IP: 68.227.160.95 X-SA-Exim-Mail-From: ebiederm@xmission.com Subject: Re: [PATCH v2 01/12] kexec: Allow architecture code to opt-out at runtime X-SA-Exim-Version: 4.2.1 (built Sat, 08 Feb 2020 21:53:50 +0000) X-SA-Exim-Scanned: Yes (on in01.mta.xmission.com) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Borislav Petkov writes: > On Mon, Sep 13, 2021 at 05:55:52PM +0200, Joerg Roedel wrote: >> From: Joerg Roedel >> >> Allow a runtime opt-out of kexec support for architecture code in case >> the kernel is running in an environment where kexec is not properly >> supported yet. >> >> This will be used on x86 when the kernel is running as an SEV-ES >> guest. SEV-ES guests need special handling for kexec to hand over all >> CPUs to the new kernel. This requires special hypervisor support and >> handling code in the guest which is not yet implemented. >> >> Cc: stable@vger.kernel.org # v5.10+ >> Signed-off-by: Joerg Roedel >> --- >> include/linux/kexec.h | 1 + >> kernel/kexec.c | 14 ++++++++++++++ >> kernel/kexec_file.c | 9 +++++++++ >> 3 files changed, 24 insertions(+) > > I guess I can take this through the tip tree along with the next one. I seem to remember the consensus when this was reviewed that it was unnecessary and there is already support for doing something like this at a more fine grained level so we don't need a new kexec hook. Eric