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 B3172C433E1 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 8D137619A2 for ; Mon, 22 Mar 2021 19:12:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232224AbhCVTMY (ORCPT ); Mon, 22 Mar 2021 15:12:24 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:48821 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231782AbhCVTMG (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-wr1-f70.google.com (mail-wr1-f70.google.com [209.85.221.70]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-222-cwzgFPBPNd690bXxy4CTTw-1; Mon, 22 Mar 2021 15:12:01 -0400 X-MC-Unique: cwzgFPBPNd690bXxy4CTTw-1 Received: by mail-wr1-f70.google.com with SMTP id s10so26590944wre.0 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=WLJTaw2NI7XLpe31FIkNfXMKLJ7mx0VEtrM/7BswhCaYyC5SNANGSALE7/3xjHL++4 OH1bIau7JryL/Pu0oQWaXmOcZBqfG/fwnzO6ploJhnkEcrUNLSQc7Satv3eA3hZ+yM9P 05HHdNO7xbMsYIOaO5F7qtkxklM6ExaDdxtaAkrp+aIVtp73odLtd/9S5iMRbYdsT8r+ ybtKZ+YKNTI4GGpO2/48+0BVHKHInw/0no+6RxcV7Ese08R5CdRYnBYg4pymIGMUDfVT SsQFucbmUO4FgowjDN+ekrmT7wVGgTrAkc3JJrUZn4hZrlmIAcaAe0tLPsEEcIidPiQU owcg== X-Gm-Message-State: AOAM533wppDOox8e9zZpMq9E8fSCO3ZTmqeCTj1dYO8ebw3iMAA3hqXM filckIjzz8a1LfCuYeHDtoUmcxQV0CDHSYy9FocNS8XVeOyeEVm45+/lAN73jJHq6+dX8/7L9Xm 3/WAHHfyBMpZt X-Received: by 2002:adf:d1cd:: with SMTP id b13mr71229wrd.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: kvm@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