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=-5.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 3E9B0C43603 for ; Thu, 5 Dec 2019 10:56:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 10EB724648 for ; Thu, 5 Dec 2019 10:56:02 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="dHIxLFOp" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729017AbfLEK4B (ORCPT ); Thu, 5 Dec 2019 05:56:01 -0500 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:45022 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728735AbfLEK4B (ORCPT ); Thu, 5 Dec 2019 05:56:01 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1575543359; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=dcSvDAAQF2KhEEObz4gP9gUoPID8X22sgxJqtYom4vk=; b=dHIxLFOpBSaGAJ2NjmbrnSpu6bHEaAut6OiTOEnGrnGH9QZYqBcX19oRdVr2I/A+xWcoDc dlG3UV1JD1isgYsEeumv0oYR+RfrP1LSbI0mMFqE7Lkdbczxv8vohG6FfNZnUFE3C4qYly URdMXn7/l+AygeMyeWfjjoson7OQa4g= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-274-3ho80iwfOzeRYyNYyHkmRA-1; Thu, 05 Dec 2019 05:55:56 -0500 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 357A2800D41; Thu, 5 Dec 2019 10:55:54 +0000 (UTC) Received: from dhcp-128-65.nay.redhat.com (ovpn-12-23.pek2.redhat.com [10.72.12.23]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 813305D9C5; Thu, 5 Dec 2019 10:55:49 +0000 (UTC) Date: Thu, 5 Dec 2019 18:55:45 +0800 From: Dave Young To: Ingo Molnar Cc: linux-efi@vger.kernel.org, x86@kernel.org, linux-kernel@vger.kernel.org, Michael Weiser , Ard Biesheuvel , kexec@lists.infradead.org, Ingo Molnar , Borislav Petkov , "Eric W. Biederman" , "H. Peter Anvin" , Thomas Gleixner Subject: Re: [PATCH] x86/efi: update e820 about reserved EFI boot services data to fix kexec breakage Message-ID: <20191205105545.GA6710@dhcp-128-65.nay.redhat.com> References: <20191204075233.GA10520@dhcp-128-65.nay.redhat.com> <20191204075917.GA10587@dhcp-128-65.nay.redhat.com> <20191204101412.GD114697@gmail.com> MIME-Version: 1.0 In-Reply-To: <20191204101412.GD114697@gmail.com> User-Agent: Mutt/1.12.1 (2019-06-15) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-MC-Unique: 3ho80iwfOzeRYyNYyHkmRA-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Content-Disposition: inline Sender: linux-efi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-efi@vger.kernel.org On 12/04/19 at 11:14am, Ingo Molnar wrote: >=20 > * Dave Young wrote: >=20 > > On 12/04/19 at 03:52pm, Dave Young wrote: > > > Michael Weiser reported he got below error during a kexec rebooting: > > > esrt: Unsupported ESRT version 2904149718861218184. > > >=20 > > > The ESRT memory stays in EFI boot services data, and it was reserved > > > in kernel via efi_mem_reserve(). The initial purpose of the reservat= ion > > > is to reuse the EFI boot services data across kexec reboot. For examp= le > > > the BGRT image data and some ESRT memory like Michael reported.=20 > > >=20 > > > But although the memory is reserved it is not updated in X86 e820 tab= le. > > > And kexec_file_load iterate system ram in io resource list to find pl= aces > > > for kernel, initramfs and other stuff. In Michael's case the kexec lo= aded > > > initramfs overwritten the ESRT memory and then the failure happened. > >=20 > > s/overwritten/overwrote :) If need a repost please let me know.. > >=20 > > >=20 > > > Since kexec_file_load depends on the e820 to be updated, just fix thi= s > > > by updating the reserved EFI boot services memory as reserved type in= e820. > > >=20 > > > Originally any memory descriptors with EFI_MEMORY_RUNTIME attribute a= re > > > bypassed in the reservation code path because they are assumed as res= erved. > > > But the reservation is still needed for multiple kexec reboot. > > > And it is the only possible case we come here thus just drop the code > > > chunk then everything works without side effects.=20 > > >=20 > > > On my machine the ESRT memory sits in an EFI runtime data range, it d= oes > > > not trigger the problem, but I successfully tested with BGRT instead. > > > both kexec_load and kexec_file_load work and kdump works as well. > > >=20 > > > Signed-off-by: Dave Young >=20 >=20 > So I edited this to: >=20 > From: Dave Young >=20 > Michael Weiser reported he got this error during a kexec rebooting: >=20 > esrt: Unsupported ESRT version 2904149718861218184. >=20 > The ESRT memory stays in EFI boot services data, and it was reserved > in kernel via efi_mem_reserve(). The initial purpose of the reservation > is to reuse the EFI boot services data across kexec reboot. For example > the BGRT image data and some ESRT memory like Michael reported. >=20 > But although the memory is reserved it is not updated in the X86 E820 ta= ble, > and kexec_file_load() iterates system RAM in the IO resource list to fin= d places > for kernel, initramfs and other stuff. In Michael's case the kexec loade= d > initramfs overwrote the ESRT memory and then the failure happened. >=20 > Since kexec_file_load() depends on the E820 table being updated, just fi= x this > by updating the reserved EFI boot services memory as reserved type in E8= 20. >=20 > Originally any memory descriptors with EFI_MEMORY_RUNTIME attribute are > bypassed in the reservation code path because they are assumed as reserv= ed. >=20 > But the reservation is still needed for multiple kexec reboots, > and it is the only possible case we come here thus just drop the code > chunk, then everything works without side effects. >=20 > On my machine the ESRT memory sits in an EFI runtime data range, it does > not trigger the problem, but I successfully tested with BGRT instead. > both kexec_load() and kexec_file_load() work and kdump works as well. >=20 Thanks for the amending, also thank all for the review and test. Dave