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 AC41FC3DA78 for ; Tue, 17 Jan 2023 09:10:50 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pHhyh-0001Vo-RC; Tue, 17 Jan 2023 04:09:59 -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 1pHhyc-0001Sa-Vv for qemu-devel@nongnu.org; Tue, 17 Jan 2023 04:09:55 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pHhyb-0003Gi-JS for qemu-devel@nongnu.org; Tue, 17 Jan 2023 04:09:54 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1673946593; 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=cmE1EToF7FK1PhWv4licRkfgkaPfpMdX2S2fwec8xmg=; b=fs/aSa6hUBsWEEDCbvteZKqFOThi5sT3zrWLfKfPAwiB5w+jQ9oGNT63XEQFzi7XEWDKKQ lh44WuEXyS7mWHo40JWI3Ikk5ZSVOcxbE1uCK0BznlVBJ672m8Ss/o9GxJeFwd66BGyLxf ZUDQ3fsyYZ3/PuYNi0WKbCu3U56V0+U= Received: from mail-qt1-f200.google.com (mail-qt1-f200.google.com [209.85.160.200]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_128_GCM_SHA256) id us-mta-290-OuHazmYWNtWYPlIdLazN_Q-1; Tue, 17 Jan 2023 04:09:51 -0500 X-MC-Unique: OuHazmYWNtWYPlIdLazN_Q-1 Received: by mail-qt1-f200.google.com with SMTP id f10-20020ac8134a000000b003b2dde42a4fso4220062qtj.4 for ; Tue, 17 Jan 2023 01:09:51 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=cmE1EToF7FK1PhWv4licRkfgkaPfpMdX2S2fwec8xmg=; b=zewnHMpsLb9DzkYJgWqw8lYKEIG19PpcgqMEWoK045VHDUFmUdJm5osqWt0MuFICa2 UTZ1uXAATD7EpKh0C+qzVKLEkB3yFPBjnbX5c2K+NT646WQMjLNO+yw6vVnD0cqX7+Ue wy4ZT4/X1eckTosdG+9Qg7WKsiNHqUimME8sa6N/w5/hDuy54rttEzgPE6PfIjfcAG2a DaJXpNdFk4mLq7WNXPEKMiGM5mm194zyW99uv2v/C3wr9lc8BNKqrhtpdMo2mNWcIgi1 NWh5Wcwo7kniYd/R+hIoYCWyrwfPEj6xHZ8OZsD/fSG9+RWTPt2SNmN/1pS0P518pqPd 0i+g== X-Gm-Message-State: AFqh2krWulxiZyQRf65WdoQ27VyXV5ML298t3iwhfCvcvVh4wMtRgXNh 6K88VLIHm0k7r29SMZhMiY043vl75B+mrfIaoaqba/QaA3IKynVqIM1JGtbcqDxJNf061AEww6v erIbwVIAYsxzUASk= X-Received: by 2002:a05:622a:5a91:b0:3b6:414f:c2ba with SMTP id fz17-20020a05622a5a9100b003b6414fc2bamr1684916qtb.38.1673946591099; Tue, 17 Jan 2023 01:09:51 -0800 (PST) X-Google-Smtp-Source: AMrXdXt329/71WT+ZQg+neZRVbjrhGpx046DLiWjspjYhDSFjQkhP01Kh7IagzUjHkQ9/4MFqtqgmg== X-Received: by 2002:a05:622a:5a91:b0:3b6:414f:c2ba with SMTP id fz17-20020a05622a5a9100b003b6414fc2bamr1684892qtb.38.1673946590852; Tue, 17 Jan 2023 01:09:50 -0800 (PST) Received: from [192.168.0.2] (ip-109-43-177-26.web.vodafone.de. [109.43.177.26]) by smtp.gmail.com with ESMTPSA id e26-20020ac8491a000000b003b62fcd6d50sm409538qtq.28.2023.01.17.01.09.48 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 17 Jan 2023 01:09:50 -0800 (PST) Message-ID: Date: Tue, 17 Jan 2023 10:09:47 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.13.0 Subject: Re: [PATCH v3 2/3] s390x/pv: Introduce a s390_pv_check() helper for runtime Content-Language: en-US To: Janosch Frank , =?UTF-8?Q?C=c3=a9dric_Le_Goater?= , qemu-s390x@nongnu.org Cc: qemu-devel@nongnu.org, Halil Pasic , Christian Borntraeger , Claudio Imbrenda , David Hildenbrand , Ilya Leoshkevich , Eric Farman , Sebastian Mitterle , =?UTF-8?Q?C=c3=a9dric_Le_Goater?= References: <20230116174607.2459498-1-clg@kaod.org> <20230116174607.2459498-3-clg@kaod.org> From: Thomas Huth In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=170.10.133.124; envelope-from=thuth@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -21 X-Spam_score: -2.2 X-Spam_bar: -- X-Spam_report: (-2.2 / 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, NICE_REPLY_A=-0.097, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-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: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On 17/01/2023 09.40, Janosch Frank wrote: > On 1/16/23 18:46, Cédric Le Goater wrote: >> From: Cédric Le Goater >> >> If a secure kernel is started in a non-protected VM, the OS will hang >> during boot without giving a proper error message to the user. > > Didn't we establish that you were missing the IOMMU flag so this statement > isn't correct anymore? > > > I haven't yet fully ingested my coffee, but from what I understand you would > block a switch into PV mode if cgs is not set. Which would mean that PV KVM > unit tests wouldn't start anymore as well as any VMs that have the unpack > feature but not cgs. > > And that's not something that we want. > > You can start a PV VM without cgs if unpack is in the CPU model. The ONLY > requirement that we should fail on is unpack. So would it make sense to check for S390_FEAT_UNPACK (or something else?) here, or should the patch completely be dropped instead? Thomas