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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 434C6E77187 for ; Tue, 17 Dec 2024 14:29:12 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1tNYZH-0000oC-QU; Tue, 17 Dec 2024 09:29:00 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1tNYZD-0000jm-OG for qemu-devel@nongnu.org; Tue, 17 Dec 2024 09:28:56 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1tNYZB-0004vE-8w for qemu-devel@nongnu.org; Tue, 17 Dec 2024 09:28:55 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1734445731; h=from:from:reply-to: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=MJW9xnEDOcxQWtRflbCqPWqvmcKAnhbeHQpZcHs/d74=; b=XspSWEY0idWw4J1uGh11mz9o6FQLTRSaawcgEAO3SSoYDLCAS4QDA58jGn/KOdhSavm3og vyS+Ezc3zi1X2rf2OKS4EBVpA51m+6J7qacP9Xm57/kVztEdyWcHz0DsFK32OXnsNmd7lP 47OgGOcEy9qPE71qxoVJrhwDKVY0I08= Received: from mx-prod-mc-04.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-213-HXG03kKrNSKOfdVGjeOxYA-1; Tue, 17 Dec 2024 09:28:50 -0500 X-MC-Unique: HXG03kKrNSKOfdVGjeOxYA-1 X-Mimecast-MFC-AGG-ID: HXG03kKrNSKOfdVGjeOxYA Received: from mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 8160619560B2; Tue, 17 Dec 2024 14:28:47 +0000 (UTC) Received: from redhat.com (unknown [10.42.28.136]) by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id A01A1300F9B7; Tue, 17 Dec 2024 14:28:42 +0000 (UTC) Date: Tue, 17 Dec 2024 14:28:40 +0000 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Gerd Hoffmann Cc: qemu-devel@nongnu.org, Zhao Liu , Marcel Apfelbaum , Yanan Wang , Paolo Bonzini , Eduardo Habkost , "Michael S. Tsirkin" , Richard Henderson , Philippe =?utf-8?Q?Mathieu-Daud=C3=A9?= Subject: Re: [PULL 3/7] x86/loader: expose unpatched kernel Message-ID: References: <20241216105053.246204-1-kraxel@redhat.com> <20241216105053.246204-4-kraxel@redhat.com> <52zucjcan5q4dwgsdchkwqi6bhdfx3ziw7ud52rratqhyzikci@3ainfgz6e4yp> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <52zucjcan5q4dwgsdchkwqi6bhdfx3ziw7ud52rratqhyzikci@3ainfgz6e4yp> User-Agent: Mutt/2.2.13 (2024-03-09) X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 Received-SPF: pass client-ip=170.10.129.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -31 X-Spam_score: -3.2 X-Spam_bar: --- X-Spam_report: (-3.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-1.116, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Tue, Dec 17, 2024 at 03:26:35PM +0100, Gerd Hoffmann wrote: > On Tue, Dec 17, 2024 at 02:15:15PM +0000, Daniel P. Berrangé wrote: > > On Mon, Dec 16, 2024 at 11:50:49AM +0100, Gerd Hoffmann wrote: > > > Add a new "etc/boot/kernel" fw_cfg file, containing the kernel without > > > the setup header patches. Intended use is booting in UEFI with secure > > > boot enabled, where the setup header patching breaks secure boot > > > verification. > > > > > > Needs OVMF changes too to be actually useful. > > > > > > Signed-off-by: Gerd Hoffmann > > > Message-ID: <20240905141211.1253307-5-kraxel@redhat.com> > > > --- > > > hw/i386/x86-common.c | 3 +++ > > > 1 file changed, 3 insertions(+) > > > > > > diff --git a/hw/i386/x86-common.c b/hw/i386/x86-common.c > > > index 28341b42d949..1cef3045ad83 100644 > > > --- a/hw/i386/x86-common.c > > > +++ b/hw/i386/x86-common.c > > > @@ -962,6 +962,9 @@ void x86_load_linux(X86MachineState *x86ms, > > > sev_load_ctx.setup_data = (char *)setup; > > > sev_load_ctx.setup_size = setup_size; > > > > > > + /* kernel without setup header patches */ > > > + fw_cfg_add_file(fw_cfg, "etc/boot/kernel", kernel, kernel_size); > > > + > > > > How concerned should we be about the memory duplication overhead > > from loading the kernel image twice ? > > It's not loaded twice, see 214191f6b574 ("x86/loader: read complete > kernel"), both fw_cfg entries point to the same memory block. Ah, I see now, that's subtle :-) With regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|