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=-13.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=unavailable 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 E311FC4320A for ; Thu, 12 Aug 2021 15:41:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C9DFB60D07 for ; Thu, 12 Aug 2021 15:41:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238121AbhHLPly (ORCPT ); Thu, 12 Aug 2021 11:41:54 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:36183 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237413AbhHLPlx (ORCPT ); Thu, 12 Aug 2021 11:41:53 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1628782887; 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=wVAySSNkRIQjjk+QH2YkijF+uGWoxw5I4DLvZClTw1U=; b=D134bOSUHTTA0PBGBrfxeua3cjVaITA/aBeygqqG9zTT1sBhyUKi2w0KPInxk3bKwqOzda u1EV3dEohJvWbbo8vwT6klqVzAk0hvI/pwYaAxSyJm/zBxIB/ODa88m6P0j4NYOD9d2vrb uM+rN2JHSIrzqz2iA+75RisxeW/qbCg= Received: from mail-ed1-f71.google.com (mail-ed1-f71.google.com [209.85.208.71]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-86-wZL33MRCOdiRFLiRosI_kw-1; Thu, 12 Aug 2021 11:41:26 -0400 X-MC-Unique: wZL33MRCOdiRFLiRosI_kw-1 Received: by mail-ed1-f71.google.com with SMTP id z4-20020a05640240c4b02903be90a10a52so3211032edb.19 for ; Thu, 12 Aug 2021 08:41:25 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=wVAySSNkRIQjjk+QH2YkijF+uGWoxw5I4DLvZClTw1U=; b=rV6J6AogI5miqXfyfLDz1Z1+PJunU2QE84mMz/sFPg8W0QBUEDxrM8/GfQ6D3hNZxi sShg6+FQKeHOBL8VVNSiHg7HL483QMWsCMSrByj9ODvaWJ+2HoQlMG8SkvTcqwR5hqLq LwoUyvcmJ0g8f4KUmtMrzotrJwk1CW5BYxQbEI9p5qG6pPGvQ/8t2x2W6TLJgmNHZnXM SJlfx+Y9X40HViihiK71XqWbB8XuluvpNvwEWLYRVX/hPf3tKfcjH8jrBCB6SG17X0HU xt0mudKOVHPODjmNIdjiPR/lO7XlJiTe/hQda8hUezzM3Tqv1xeNmhb1ak4ksT7CTMF6 h1Rw== X-Gm-Message-State: AOAM532GqyYFQTj67KgQRI6J/qes4WARf+U4ad76BIgodmklM7u/A2jY h6CRCpqzVcS8EvTO8oT6Qp07BxDpQLWvRY17BvWurW3XYReyc/xTShrscw46teiKV4DOw4xUqUG YbMdRbCM+dFrDhdE+EarfA/sR X-Received: by 2002:a50:ef11:: with SMTP id m17mr6095912eds.233.1628782885025; Thu, 12 Aug 2021 08:41:25 -0700 (PDT) X-Google-Smtp-Source: ABdhPJzbkauFimraFjcUcxW/s5naeDzEHblJnwTGW5kN8SFMxVNVXXtWI2AkXQ1TgeG7maJbDTkRTw== X-Received: by 2002:a50:ef11:: with SMTP id m17mr6095860eds.233.1628782884809; Thu, 12 Aug 2021 08:41:24 -0700 (PDT) Received: from ?IPv6:2001:b07:6468:f312:c8dd:75d4:99ab:290a? ([2001:b07:6468:f312:c8dd:75d4:99ab:290a]) by smtp.gmail.com with ESMTPSA id s18sm988134ejh.12.2021.08.12.08.41.22 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 12 Aug 2021 08:41:24 -0700 (PDT) Subject: Re: [PATCH v2 1/2] KVM: Refactor kvm_arch_vcpu_fault() to return a struct page pointer To: David Hildenbrand , Hou Wenlong , kvm@vger.kernel.org Cc: Sean Christopherson , Marc Zyngier , James Morse , Alexandru Elisei , Suzuki K Poulose , Catalin Marinas , Will Deacon , Huacai Chen , Aleksandar Markovic , Thomas Bogendoerfer , Paul Mackerras , Michael Ellerman , Benjamin Herrenschmidt , Christian Borntraeger , Janosch Frank , Cornelia Huck , Claudio Imbrenda , Heiko Carstens , Vasily Gorbik , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , Thomas Gleixner , Ingo Molnar , Borislav Petkov , x86@kernel.org, "H. Peter Anvin" , linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org, linux-mips@vger.kernel.org, kvm-ppc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org References: <1c510b24fc1d7cbae8aa4b69c0799ebd32e65b82.1628739116.git.houwenlong93@linux.alibaba.com> <98adbd3c-ec6f-5689-1686-2a8a7909951a@redhat.com> From: Paolo Bonzini Message-ID: Date: Thu, 12 Aug 2021 17:41:22 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: <98adbd3c-ec6f-5689-1686-2a8a7909951a@redhat.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/08/21 11:04, David Hildenbrand wrote: > > Reviewed-by: David Hildenbrand > > But at the same time I wonder if we should just get rid of > CONFIG_KVM_S390_UCONTROL and consequently kvm_arch_vcpu_fault(). > > In practice CONFIG_KVM_S390_UCONTROL, is never enabled in any reasonable > kernel build and consequently it's never tested; further, exposing the > sie_block to user space allows user space to generate random SIE > validity intercepts. > > CONFIG_KVM_S390_UCONTROL feels like something that should just be > maintained out of tree by someone who really needs to hack deep into hw > virtualization for testing purposes etc. I have no preference either way. It should definitely have selftests, but in x86 land there are some features that are not covered by QEMU and were nevertheless accepted upstream with selftests. 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([2001:b07:6468:f312:c8dd:75d4:99ab:290a]) by smtp.gmail.com with ESMTPSA id s18sm988134ejh.12.2021.08.12.08.41.22 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 12 Aug 2021 08:41:24 -0700 (PDT) Subject: Re: [PATCH v2 1/2] KVM: Refactor kvm_arch_vcpu_fault() to return a struct page pointer To: David Hildenbrand , Hou Wenlong , kvm@vger.kernel.org References: <1c510b24fc1d7cbae8aa4b69c0799ebd32e65b82.1628739116.git.houwenlong93@linux.alibaba.com> <98adbd3c-ec6f-5689-1686-2a8a7909951a@redhat.com> From: Paolo Bonzini Message-ID: Date: Thu, 12 Aug 2021 17:41:22 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: <98adbd3c-ec6f-5689-1686-2a8a7909951a@redhat.com> Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=pbonzini@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: x86@kernel.org, Wanpeng Li , linux-mips@vger.kernel.org, "H. Peter Anvin" , Claudio Imbrenda , Will Deacon , kvmarm@lists.cs.columbia.edu, linux-s390@vger.kernel.org, Janosch Frank , Marc Zyngier , Joerg Roedel , Huacai Chen , Christian Borntraeger , Aleksandar Markovic , Ingo Molnar , Catalin Marinas , Vasily Gorbik , Suzuki K Poulose , Heiko Carstens , kvm-ppc@vger.kernel.org, Borislav Petkov , Thomas Gleixner , Alexandru Elisei , linux-arm-kernel@lists.infradead.org, Jim Mattson , Thomas Bogendoerfer , Sean Christopherson , Cornelia Huck , linux-kernel@vger.kernel.org, James Morse , Vitaly Kuznetsov , linuxppc-dev@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On 12/08/21 11:04, David Hildenbrand wrote: > > Reviewed-by: David Hildenbrand > > But at the same time I wonder if we should just get rid of > CONFIG_KVM_S390_UCONTROL and consequently kvm_arch_vcpu_fault(). > > In practice CONFIG_KVM_S390_UCONTROL, is never enabled in any reasonable > kernel build and consequently it's never tested; further, exposing the > sie_block to user space allows user space to generate random SIE > validity intercepts. > > CONFIG_KVM_S390_UCONTROL feels like something that should just be > maintained out of tree by someone who really needs to hack deep into hw > virtualization for testing purposes etc. I have no preference either way. It should definitely have selftests, but in x86 land there are some features that are not covered by QEMU and were nevertheless accepted upstream with selftests. Paolo 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=-10.1 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, 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 D078AC4338F for ; Thu, 12 Aug 2021 15:41:34 +0000 (UTC) Received: from mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by mail.kernel.org (Postfix) with ESMTP id 4D41360FD7 for ; Thu, 12 Aug 2021 15:41:34 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 4D41360FD7 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=lists.cs.columbia.edu Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id AC7FE49F6C; Thu, 12 Aug 2021 11:41:33 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu Authentication-Results: mm01.cs.columbia.edu (amavisd-new); dkim=softfail (fail, message has been altered) header.i=@redhat.com Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id HhEOG+Xc+2LP; Thu, 12 Aug 2021 11:41:29 -0400 (EDT) Received: from mm01.cs.columbia.edu (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id CE2254A1A5; Thu, 12 Aug 2021 11:41:29 -0400 (EDT) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id AF3FE49FA6 for ; Thu, 12 Aug 2021 11:41:28 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id yrbJKFGy2SrM for ; Thu, 12 Aug 2021 11:41:27 -0400 (EDT) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [216.205.24.124]) by mm01.cs.columbia.edu (Postfix) with ESMTP id BFA8649F6C for ; Thu, 12 Aug 2021 11:41:27 -0400 (EDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1628782887; 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=wVAySSNkRIQjjk+QH2YkijF+uGWoxw5I4DLvZClTw1U=; b=D134bOSUHTTA0PBGBrfxeua3cjVaITA/aBeygqqG9zTT1sBhyUKi2w0KPInxk3bKwqOzda u1EV3dEohJvWbbo8vwT6klqVzAk0hvI/pwYaAxSyJm/zBxIB/ODa88m6P0j4NYOD9d2vrb uM+rN2JHSIrzqz2iA+75RisxeW/qbCg= Received: from mail-ed1-f72.google.com (mail-ed1-f72.google.com [209.85.208.72]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-153-3iGGivdbM3qee5gKY_ZZwA-1; Thu, 12 Aug 2021 11:41:26 -0400 X-MC-Unique: 3iGGivdbM3qee5gKY_ZZwA-1 Received: by mail-ed1-f72.google.com with SMTP id b16-20020a0564022790b02903be6352006cso3217897ede.15 for ; Thu, 12 Aug 2021 08:41:25 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=wVAySSNkRIQjjk+QH2YkijF+uGWoxw5I4DLvZClTw1U=; b=SBtNHyTQRo75GuoTMwO+AcFOS1P6E2MtvlaUQr53CixpGDjIYpGWs0DEvj3vB0rrCX ZIzshK8QoWHB9HWcPanlKr2QqUaJYJfGi0fwJ9a5GBAMOoe6Yasv6qr89N3fS9EHih5d c0XFppqW7dVwhRof5eFb/vAF6SykpBGiK/+b3uQk43pQZSmkHuC+Zkhbbwfhy5+wLQHD ch9OL0k7U0tUO/56z+vZgT8AzvExS9iQKfK66F3tAADGk+5gRkjcyj2yQo1zyhm8al3f JPOGbOWcYj/bF/09uePKYbzjLKSTZ4nqimfmzUDjRVzneWDjujm3QPjl28VuN0oTZNgR E16g== X-Gm-Message-State: AOAM530h6FUaJADu2BxX1Fm6GoWR8OhW7z92JY2PkkDjnAhZq13yA3DQ pUgOjzSnpKYhi/FpVIslmINuICZhYYJiP2fZpdbmKkjT56QcaONsVTYzb1q84ilQn1ShaxQ9OCf wDx2Yh+iUVvQa3oAA6fI1nFF6 X-Received: by 2002:a50:ef11:: with SMTP id m17mr6095922eds.233.1628782885033; Thu, 12 Aug 2021 08:41:25 -0700 (PDT) X-Google-Smtp-Source: ABdhPJzbkauFimraFjcUcxW/s5naeDzEHblJnwTGW5kN8SFMxVNVXXtWI2AkXQ1TgeG7maJbDTkRTw== X-Received: by 2002:a50:ef11:: with SMTP id m17mr6095860eds.233.1628782884809; Thu, 12 Aug 2021 08:41:24 -0700 (PDT) Received: from ?IPv6:2001:b07:6468:f312:c8dd:75d4:99ab:290a? ([2001:b07:6468:f312:c8dd:75d4:99ab:290a]) by smtp.gmail.com with ESMTPSA id s18sm988134ejh.12.2021.08.12.08.41.22 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 12 Aug 2021 08:41:24 -0700 (PDT) Subject: Re: [PATCH v2 1/2] KVM: Refactor kvm_arch_vcpu_fault() to return a struct page pointer To: David Hildenbrand , Hou Wenlong , kvm@vger.kernel.org References: <1c510b24fc1d7cbae8aa4b69c0799ebd32e65b82.1628739116.git.houwenlong93@linux.alibaba.com> <98adbd3c-ec6f-5689-1686-2a8a7909951a@redhat.com> From: Paolo Bonzini Message-ID: Date: Thu, 12 Aug 2021 17:41:22 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: <98adbd3c-ec6f-5689-1686-2a8a7909951a@redhat.com> Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=pbonzini@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Language: en-US Cc: x86@kernel.org, Wanpeng Li , Benjamin Herrenschmidt , linux-mips@vger.kernel.org, Paul Mackerras , "H. Peter Anvin" , Claudio Imbrenda , Will Deacon , kvmarm@lists.cs.columbia.edu, linux-s390@vger.kernel.org, Janosch Frank , Marc Zyngier , Joerg Roedel , Huacai Chen , Christian Borntraeger , Aleksandar Markovic , Ingo Molnar , Catalin Marinas , Vasily Gorbik , Heiko Carstens , kvm-ppc@vger.kernel.org, Borislav Petkov , Thomas Gleixner , linux-arm-kernel@lists.infradead.org, Jim Mattson , Thomas Bogendoerfer , Sean Christopherson , Cornelia Huck , linux-kernel@vger.kernel.org, Michael Ellerman , Vitaly Kuznetsov , linuxppc-dev@lists.ozlabs.org X-BeenThere: kvmarm@lists.cs.columbia.edu X-Mailman-Version: 2.1.14 Precedence: list List-Id: Where KVM/ARM decisions are made List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu On 12/08/21 11:04, David Hildenbrand wrote: > > Reviewed-by: David Hildenbrand > > But at the same time I wonder if we should just get rid of > CONFIG_KVM_S390_UCONTROL and consequently kvm_arch_vcpu_fault(). > > In practice CONFIG_KVM_S390_UCONTROL, is never enabled in any reasonable > kernel build and consequently it's never tested; further, exposing the > sie_block to user space allows user space to generate random SIE > validity intercepts. > > CONFIG_KVM_S390_UCONTROL feels like something that should just be > maintained out of tree by someone who really needs to hack deep into hw > virtualization for testing purposes etc. I have no preference either way. It should definitely have selftests, but in x86 land there are some features that are not covered by QEMU and were nevertheless accepted upstream with selftests. Paolo _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm 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=-11.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, 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 444C5C432BE for ; Thu, 12 Aug 2021 15:44:53 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E2A5C60D07 for ; Thu, 12 Aug 2021 15:44:52 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org E2A5C60D07 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Content-Type: Content-Transfer-Encoding:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date:Message-ID:From: References:Cc:To:Subject:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=3CAwV2taXP4HTYph9E4OJjWhQX6yx8rQgHkL2nqGPK0=; b=yjnI4TO2rly7LitF80GqiylAqn Dm84cxFBs/wHXj5cX4kubGvkkA3j9ETI91dTwCsiYYe4toT+x+nEJR1a83CKVLQTf8QTFzXvtHrvg 4ryzIoTlpYLXh7c3YvpISEyk1HlkXe95lUK+JE/dMv+s87sTDYQfVnGjGrRtgW3y6kRLpLgTad0iP tRvuIFIorKGxZkssaOfj3lozIaF+Zez3jMkSEuI60kaAkIU5z0R2rqdsWMYhwbnLGO9dBiciU6UX1 Qop+50g8um374RHdfHS/pwX9hvDSxFt0gzxmMMfCQDzbJtyDpImfPZGg0d7VSFnGor/M3BWNtikDC Lk3bvEww==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mECpp-00AZp4-P0; Thu, 12 Aug 2021 15:41:33 +0000 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1mECpm-00AZoP-MP for linux-arm-kernel@lists.infradead.org; Thu, 12 Aug 2021 15:41:31 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1628782887; 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=wVAySSNkRIQjjk+QH2YkijF+uGWoxw5I4DLvZClTw1U=; b=D134bOSUHTTA0PBGBrfxeua3cjVaITA/aBeygqqG9zTT1sBhyUKi2w0KPInxk3bKwqOzda u1EV3dEohJvWbbo8vwT6klqVzAk0hvI/pwYaAxSyJm/zBxIB/ODa88m6P0j4NYOD9d2vrb uM+rN2JHSIrzqz2iA+75RisxeW/qbCg= Received: from mail-ej1-f70.google.com (mail-ej1-f70.google.com [209.85.218.70]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-163-wIZdYb0cP8eHiEbLVf6NDQ-1; Thu, 12 Aug 2021 11:41:26 -0400 X-MC-Unique: wIZdYb0cP8eHiEbLVf6NDQ-1 Received: by mail-ej1-f70.google.com with SMTP id j15-20020a17090643cfb02905b87bd5d2d0so1349153ejn.16 for ; Thu, 12 Aug 2021 08:41:25 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=wVAySSNkRIQjjk+QH2YkijF+uGWoxw5I4DLvZClTw1U=; b=MX1n4jQiZhmENgInqIVhKCSg8aQuHVUtwtxaNi2zo6Fjv12vH+zAhzDht7jPGGQTYj U1KmyyURGQ5zB03sp59/H5vsZrrnsCHt/0nN2xrvDuRe5ph66SqsWdKhJhNROf4cGwR9 BoDQT3UKwKJBL3J9mA6EDvzgmAcglgb442Qd/R7Gqb5PBT1dDk6WQ4IBijZ2FbM4zHhh sNnAB3xcpG+beAHVDiKrIQ9eIH+cSE9VZU/GcKUrE9StsB7aIpqcktTO4pZwb7hXmjTX 7OQ6gt3HJB4P+Yrm0O902hMtMobdB7VxPBnmthba0pfg03Hkaa/+rq436DFHH3bPCl0m bsvA== X-Gm-Message-State: AOAM5334LWS+EWyr2h/0wPr5i+MCu1VZnbwu5cLiuaBgolh3wbIIrxZO yncEGUOkB5gmOD4+yZYwLj9yj9TNd0dJT0GxId1vYh3TENHIPO11a1M2WMV2vMpamO+A2xtaPJm UYD4BuQm5nF+d3RQ0pxNRRrTQ6HQ2M2Qd11M= X-Received: by 2002:a50:ef11:: with SMTP id m17mr6095903eds.233.1628782885024; Thu, 12 Aug 2021 08:41:25 -0700 (PDT) X-Google-Smtp-Source: ABdhPJzbkauFimraFjcUcxW/s5naeDzEHblJnwTGW5kN8SFMxVNVXXtWI2AkXQ1TgeG7maJbDTkRTw== X-Received: by 2002:a50:ef11:: with SMTP id m17mr6095860eds.233.1628782884809; Thu, 12 Aug 2021 08:41:24 -0700 (PDT) Received: from ?IPv6:2001:b07:6468:f312:c8dd:75d4:99ab:290a? ([2001:b07:6468:f312:c8dd:75d4:99ab:290a]) by smtp.gmail.com with ESMTPSA id s18sm988134ejh.12.2021.08.12.08.41.22 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 12 Aug 2021 08:41:24 -0700 (PDT) Subject: Re: [PATCH v2 1/2] KVM: Refactor kvm_arch_vcpu_fault() to return a struct page pointer To: David Hildenbrand , Hou Wenlong , kvm@vger.kernel.org Cc: Sean Christopherson , Marc Zyngier , James Morse , Alexandru Elisei , Suzuki K Poulose , Catalin Marinas , Will Deacon , Huacai Chen , Aleksandar Markovic , Thomas Bogendoerfer , Paul Mackerras , Michael Ellerman , Benjamin Herrenschmidt , Christian Borntraeger , Janosch Frank , Cornelia Huck , Claudio Imbrenda , Heiko Carstens , Vasily Gorbik , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , Thomas Gleixner , Ingo Molnar , Borislav Petkov , x86@kernel.org, "H. Peter Anvin" , linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org, linux-mips@vger.kernel.org, kvm-ppc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org References: <1c510b24fc1d7cbae8aa4b69c0799ebd32e65b82.1628739116.git.houwenlong93@linux.alibaba.com> <98adbd3c-ec6f-5689-1686-2a8a7909951a@redhat.com> From: Paolo Bonzini Message-ID: Date: Thu, 12 Aug 2021 17:41:22 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: <98adbd3c-ec6f-5689-1686-2a8a7909951a@redhat.com> Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=pbonzini@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210812_084130_873375_B690561A X-CRM114-Status: GOOD ( 18.80 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 12/08/21 11:04, David Hildenbrand wrote: > > Reviewed-by: David Hildenbrand > > But at the same time I wonder if we should just get rid of > CONFIG_KVM_S390_UCONTROL and consequently kvm_arch_vcpu_fault(). > > In practice CONFIG_KVM_S390_UCONTROL, is never enabled in any reasonable > kernel build and consequently it's never tested; further, exposing the > sie_block to user space allows user space to generate random SIE > validity intercepts. > > CONFIG_KVM_S390_UCONTROL feels like something that should just be > maintained out of tree by someone who really needs to hack deep into hw > virtualization for testing purposes etc. I have no preference either way. It should definitely have selftests, but in x86 land there are some features that are not covered by QEMU and were nevertheless accepted upstream with selftests. Paolo _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paolo Bonzini Date: Thu, 12 Aug 2021 15:41:22 +0000 Subject: Re: [PATCH v2 1/2] KVM: Refactor kvm_arch_vcpu_fault() to return a struct page pointer Message-Id: List-Id: References: <1c510b24fc1d7cbae8aa4b69c0799ebd32e65b82.1628739116.git.houwenlong93@linux.alibaba.com> <98adbd3c-ec6f-5689-1686-2a8a7909951a@redhat.com> In-Reply-To: <98adbd3c-ec6f-5689-1686-2a8a7909951a@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: David Hildenbrand , Hou Wenlong , kvm@vger.kernel.org Cc: Sean Christopherson , Marc Zyngier , James Morse , Alexandru Elisei , Suzuki K Poulose , Catalin Marinas , Will Deacon , Huacai Chen , Aleksandar Markovic , Thomas Bogendoerfer , Paul Mackerras , Michael Ellerman , Benjamin Herrenschmidt , Christian Borntraeger , Janosch Frank , Cornelia Huck , Claudio Imbrenda , Heiko Carstens , Vasily Gorbik , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , Thomas Gleixner , Ingo Molnar , Borislav Petkov , x86@kernel.org, "H. Peter Anvin" , linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org, linux-mips@vger.kernel.org, kvm-ppc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org On 12/08/21 11:04, David Hildenbrand wrote: > > Reviewed-by: David Hildenbrand > > But at the same time I wonder if we should just get rid of > CONFIG_KVM_S390_UCONTROL and consequently kvm_arch_vcpu_fault(). > > In practice CONFIG_KVM_S390_UCONTROL, is never enabled in any reasonable > kernel build and consequently it's never tested; further, exposing the > sie_block to user space allows user space to generate random SIE > validity intercepts. > > CONFIG_KVM_S390_UCONTROL feels like something that should just be > maintained out of tree by someone who really needs to hack deep into hw > virtualization for testing purposes etc. I have no preference either way. It should definitely have selftests, but in x86 land there are some features that are not covered by QEMU and were nevertheless accepted upstream with selftests. Paolo