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=-7.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 D63B8C433E2 for ; Mon, 22 Mar 2021 19:12:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A2911619AC for ; Mon, 22 Mar 2021 19:12:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231855AbhCVTM0 (ORCPT ); Mon, 22 Mar 2021 15:12:26 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:46777 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231802AbhCVTMG (ORCPT ); Mon, 22 Mar 2021 15:12:06 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1616440323; 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=UfnyDJKd+AIhgsgjhm7fjzOjPp4nvTJYPKMus8kh4Is=; b=bcI7cGLe1VaPHFnfFGAygbBQvRmRm6Uj120jXr/uSJ8N+Kpxhzps0Yzw5aKFELXgDsZ938 C8cXWjlmhkJCKWgDQ1mNxFZFHe93xvtGmdxnOi+cpn/+4JU3tBnawt2OtlOeSenKtApKYU wcZs07JSh6pNQvvMuo12H/kve++jgy8= Received: from mail-wm1-f71.google.com (mail-wm1-f71.google.com [209.85.128.71]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-553-INax7f_yOTykSbPZMFyLlA-1; Mon, 22 Mar 2021 15:12:01 -0400 X-MC-Unique: INax7f_yOTykSbPZMFyLlA-1 Received: by mail-wm1-f71.google.com with SMTP id r18so14213wmq.5 for ; Mon, 22 Mar 2021 12:12:01 -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=UfnyDJKd+AIhgsgjhm7fjzOjPp4nvTJYPKMus8kh4Is=; b=IIE+mzic2AAymwfwtdJ0aKUnQKLgqKZY5glxC/6dbUDmUoKxT+dnNPg5p5gOpJ1mIA sP7BS9tLB/RK4wfCGNjgqPF+5IlW/zgINuZ/TWrGvrqCumZ5TW/tgu+GRuHH0pEm/MeJ uaBTU9Miw53eIajU3Jzwe1CW456n61+YCUWB/AkJRP3kbl7Lau2+BS0GEUW83DawdGeU 9M7eno9hKCW0a2LCSLI/pBOv2zg6hROZ1apY3VJ7wM+g1rzojMOkjPzeVlxYbtwqxVKR UpaDT5RPlhmEOsySI2tOUJYjVDfqorMB1zCa6qy55Ur9s/3VMTw6eJCGI+nNhvWXMbUU mfrw== X-Gm-Message-State: AOAM531YX6vxTZyoUcSEEyNxQw4AzZFiAWGRsztbSE2sLnbeMBKZ3GZE gV+ERKOACdUwinpH7UH1UD9F3nNNVybrx37CJm6NA/XwTAPiDz6Fy1w9qXCHs7ZHkLx9g2DHpWr DjO4ah56/gq+vPIXlJ1ISZd7v X-Received: by 2002:adf:d1cd:: with SMTP id b13mr71227wrd.47.1616440320267; Mon, 22 Mar 2021 12:12:00 -0700 (PDT) X-Google-Smtp-Source: ABdhPJz/cLnNqtKWv7V1/Fpeb5aRH7hZpgdnHA/Zo2qiXqHKF8asFjWbETSgysqD6vFP3G2Q+t5LNw== X-Received: by 2002:adf:d1cd:: with SMTP id b13mr71209wrd.47.1616440320100; Mon, 22 Mar 2021 12:12:00 -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 x11sm347291wme.9.2021.03.22.12.11.58 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 22 Mar 2021 12:11:59 -0700 (PDT) Subject: Re: [PATCH v3 03/25] x86/sgx: Wipe out EREMOVE from sgx_free_epc_page() To: Sean Christopherson , Borislav Petkov Cc: Kai Huang , kvm@vger.kernel.org, x86@kernel.org, linux-sgx@vger.kernel.org, linux-kernel@vger.kernel.org, jarkko@kernel.org, luto@kernel.org, dave.hansen@intel.com, rick.p.edgecombe@intel.com, haitao.huang@intel.com, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com References: <062acb801926b2ade2f9fe1672afb7113453a741.1616136308.git.kai.huang@intel.com> <20210322181646.GG6481@zn.tnic> From: Paolo Bonzini Message-ID: Date: Mon, 22 Mar 2021 20:11:57 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.7.0 MIME-Version: 1.0 In-Reply-To: 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 22/03/21 19:56, Sean Christopherson wrote: > EREMOVE can only fail if there's a kernel or hardware bug (or a VMM bug if > running as a guest). IME, nearly every kernel/KVM bug that I introduced that > led to EREMOVE failure was also quite fatal to SGX, i.e. this is just the canary > in the coal mine. That was my recollection as well from previous threads but, to be fair to Boris, the commit message is a lot more scary (and, which is what triggers me, puts the blame on KVM). It just says "KVM does not track how guest pages are used, which means that SGX virtualization use of EREMOVE might fail". Paolo