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=-7.6 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 B7AFDC433B4 for ; Mon, 17 May 2021 16:44:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 90E8B610FA for ; Mon, 17 May 2021 16:44:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241499AbhEQQpi (ORCPT ); Mon, 17 May 2021 12:45:38 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:21668 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238203AbhEQQpZ (ORCPT ); Mon, 17 May 2021 12:45:25 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1621269841; 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=pLOobSjCbQskFqMnll0HyKDl5KNjQO+RBewEeO7jSSc=; b=OJo83D5XBo7wOXIjAqfaqKpqPYo2hHSOWX/CyQqS+VStR0ePJ765qTWOk8O82gwBVxDs8l vP476E7fLp5DOabnRsEs/0ULUXmsbaIMOX6OM46ffjleolJej33Sk7aqojf+g0DXbKjqwc 3dDzxopEZ4IQvVT4f2uJcsF3B05ofCc= 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-252-JvKSz-YZM16yrEwGLw63Ag-1; Mon, 17 May 2021 12:44:00 -0400 X-MC-Unique: JvKSz-YZM16yrEwGLw63Ag-1 Received: by mail-ed1-f72.google.com with SMTP id i3-20020aa7dd030000b029038ce772ffe4so4276164edv.12 for ; Mon, 17 May 2021 09:44:00 -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=pLOobSjCbQskFqMnll0HyKDl5KNjQO+RBewEeO7jSSc=; b=fhqs5mTePUD6RjC65vFR02wfleiZuyG6i17mEJLG1w9gu3NtQfQtHZpLSBlXu8ND0G eL3s48te+vjsZWvSOMx3fBXm71mGYbXa5SVDhUIEbYl1nlo3pfhruOm28haw/ocFMiFc 0DkMIBde4I0FscBi6+dbluUqkF6/uk4jJ7qWGV0Je6VaEJCucP9UbWWlYDAH9SrogNs1 rPzPjHN8ZIJGMKxUIYsmwMQwALpuVg2eJ95MNTZOX5hfcAqSPLlwlEueE1NQGPjza7IR 1K+3Gy+i6RnuFVjfG3zaP0sM+W2W5K709Midztz4n+7261TiNBz7IfVWgmGZMaPUIwWK bl2w== X-Gm-Message-State: AOAM533kRiQZDbVvRHz901tDraY3P8Zgecd1q2HR0g7tAnYS/iO1q06m iQT4PjKiiV8Qr8s2iY9721ktztPRmpo7Qg1s4pK0K3QbtFRa7QzWHPi7MVkOJKrfZ7BH/8Une0q M4KFQsFePGN2QE8jCRANByzU4 X-Received: by 2002:a50:cdd1:: with SMTP id h17mr1149992edj.178.1621269839204; Mon, 17 May 2021 09:43:59 -0700 (PDT) X-Google-Smtp-Source: ABdhPJybcPfcPZg8fUCw2rYDP5qsCQxq7rGzcUbcnUmTWFmLAlzNQpmPlCsCiTwFNHTun2K89RcSNQ== X-Received: by 2002:a50:cdd1:: with SMTP id h17mr1149967edj.178.1621269838988; Mon, 17 May 2021 09:43:58 -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 i5sm4826603edt.11.2021.05.17.09.43.56 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 17 May 2021 09:43:58 -0700 (PDT) Subject: Re: [PATCH] KVM: x86: add hint to skip hidden rdpkru under kvm_load_host_xsave_state To: Dave Hansen , Andy Lutomirski , Jon Kohler Cc: Babu Moger , Thomas Gleixner , Ingo Molnar , Borislav Petkov , X86 ML , "H. Peter Anvin" , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , Fenghua Yu , Yu-cheng Yu , Tony Luck , Uros Bizjak , Petteri Aimonen , Kan Liang , Andrew Morton , Mike Rapoport , Benjamin Thiel , Fan Yang , Juergen Gross , Dave Jiang , "Peter Zijlstra (Intel)" , Ricardo Neri , Arvind Sankar , LKML , kvm list References: <20210507164456.1033-1-jon@nutanix.com> From: Paolo Bonzini Message-ID: Date: Mon, 17 May 2021 18:43:56 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.1 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 17/05/21 15:54, Dave Hansen wrote: > On 5/13/21 10:11 PM, Andy Lutomirski wrote: >> I don't even want to think about what happens if a perf NMI hits and >> accesses host user memory while the guest PKRU is live (on VMX -- I >> think this can't happen on SVM). > > What's the relevant difference between SVM and VMX here? I'm missing > something. SVM has the global interrupt flag that blocks NMIs and SMIs, and PKRU is loaded while GIF=0. Paolo