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 BFAC7C433FE for ; Fri, 15 Oct 2021 11:17:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9CECD611C2 for ; Fri, 15 Oct 2021 11:17:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238413AbhJOLTf (ORCPT ); Fri, 15 Oct 2021 07:19:35 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:47004 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235205AbhJOLTd (ORCPT ); Fri, 15 Oct 2021 07:19:33 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1634296645; 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=PLWLkBQXMNGKBODhUxl5sJuJicKkC9lyNhKYr16226Q=; b=Blx0XZ2/Eu6mtYzHD4XwLS+3MU7ALmWpOsWbn0cCsPAX156hC4jV6l6PUfzwX0wUJOGFD3 1PZ1whGz6Pg9CEzR9EUVg5Oqg5Z+szPCjHmfHyBq1BWS9oVFMXOmt7te1QCz24DbtXyqG0 PD79Tg2mCqVX15wx9ViZ0FOs9OhFsy0= Received: from mail-ed1-f70.google.com (mail-ed1-f70.google.com [209.85.208.70]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-510-5AVOO1v-OBCDs4q-zyMxHw-1; Fri, 15 Oct 2021 07:17:24 -0400 X-MC-Unique: 5AVOO1v-OBCDs4q-zyMxHw-1 Received: by mail-ed1-f70.google.com with SMTP id u17-20020a50d511000000b003daa3828c13so7902630edi.12 for ; Fri, 15 Oct 2021 04:17:24 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=PLWLkBQXMNGKBODhUxl5sJuJicKkC9lyNhKYr16226Q=; b=qJwo4sZlALxHUlyiigv5PlI79Le+9pRp29W5yd9xbbYFBpmZAMdF7Mn/PiuV4SgYS5 TdxMhdplxTi7yRj1Cha/an4eFqtTaOv669yOhBmTB+O10nuQGVh6l2hrA4VwHCPWAsba 9hMeVkX84Kxh7Loy7bEQM4iRxbD5lFQV8MUaOZHwnqZmNAjZV8ZVotH+ZOW/jc0A3Cls RfLUOk6s2UpFz2tj5f0h7NS0J6rEehQAtj8tjzgqO6eG4QkdRKQK4SWKlqLKJbeZi2sv TY+EZxYQF/p3lk6bgJe/86PD57vYQwm9uRYuj1iLib28XoG1Gekoq7dB97Jpdaow6DSt XniQ== X-Gm-Message-State: AOAM533Gl13/o9cJnF0i/wC7ghZSGwS7hKDrsX2bynu21bN/61jYk26M Ovb7xA10ujBJH9FQvXHVsGiaP9aY1Am86yKOJHVfWSS2yPcsaoxCfEGDI1zBa//sT650Lhrx7FV barj5mxi2+Wi0atR2LTH566En X-Received: by 2002:a17:906:bb0c:: with SMTP id jz12mr6007744ejb.455.1634296643042; Fri, 15 Oct 2021 04:17:23 -0700 (PDT) X-Google-Smtp-Source: ABdhPJzOEb5DQCjpld1lFtUIdW1j1M8acmXn5+T7Dk5kQK54CbcN1RiZW1b2pTtQEIQrCR7zp8jcUg== X-Received: by 2002:a17:906:bb0c:: with SMTP id jz12mr6007728ejb.455.1634296642862; Fri, 15 Oct 2021 04:17:22 -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 z19sm3957128ejp.97.2021.10.15.04.17.21 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 15 Oct 2021 04:17:22 -0700 (PDT) Message-ID: <37923aa8-8d86-4409-7689-3fbf8ce8ae4f@redhat.com> Date: Fri, 15 Oct 2021 13:17:20 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.1.0 Subject: Re: [patch 13/31] x86/fpu: Move KVMs FPU swapping to FPU core Content-Language: en-US To: Thomas Gleixner , "Liu, Jing2" , LKML Cc: "x86@kernel.org" , "Bae, Chang Seok" , Dave Hansen , Arjan van de Ven , "kvm@vger.kernel.org" , "Nakajima, Jun" , Jing Liu , "seanjc@google.com" , "Cooper, Andrew" References: <871r4p9fyh.ffs@tglx> <6bbc5184-a675-1937-eb98-639906a9cf15@redhat.com> <87wnmf66m5.ffs@tglx> <3997787e-402d-4b2b-0f90-4a672c77703f@redhat.com> <877dee5zpf.ffs@tglx> From: Paolo Bonzini In-Reply-To: <877dee5zpf.ffs@tglx> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 15/10/21 12:50, Thomas Gleixner wrote: > That might be matching the KVM expectations, but it's not going to > happen. > > KVM already violates all well known rules of encapsulation and just > fiddles in the guts of FPU mechanism, duplicates code in buggy ways. > > This has to stop now! FWIW, I totally agree about that. Over the years we've gotten more well-thought hooks in the kernel for KVM and less hacks, and I'll only be happy if that extends to the FPU code which I'm quite wary of touching. Most of it has been unchanged since Ingo's last rewrite. Paolo > You are free to ignore me, but all you are going to achieve is to delay > AMX integration further. Seriously, I'm not even going to reply to > anything which is not based on the above approach.