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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 41448C433F5 for ; Tue, 15 Mar 2022 21:05:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1351743AbiCOVGK (ORCPT ); Tue, 15 Mar 2022 17:06:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44704 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237862AbiCOVGF (ORCPT ); Tue, 15 Mar 2022 17:06:05 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 984B732049 for ; Tue, 15 Mar 2022 14:04:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1647378292; 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=1r/SZEsNrbQgR8XCDBtO94cGTTINRL5AaqX8Y8QKbyM=; b=axv57qRrsoR00DXvRgN/jbaZIZLZjgZQasZuOxsNTDf9ZX8MinD0UGpIms5TR3BqG07ihc BH4J6f0xXFXVikrAIuFTkFHQpJ2O0lZ9DRgIltiL87WUViLn9hQCor67MFAD9NpULMMtIe dlFYb8ZAPHS1nxwNczJYaIEZPZ6RKRU= Received: from mail-ej1-f72.google.com (mail-ej1-f72.google.com [209.85.218.72]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-414-AqYK5qVxPAq8Kx4BRmbFkA-1; Tue, 15 Mar 2022 17:04:51 -0400 X-MC-Unique: AqYK5qVxPAq8Kx4BRmbFkA-1 Received: by mail-ej1-f72.google.com with SMTP id hy9-20020a1709068a6900b006df68012720so42401ejc.14 for ; Tue, 15 Mar 2022 14:04:51 -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=1r/SZEsNrbQgR8XCDBtO94cGTTINRL5AaqX8Y8QKbyM=; b=h86+K5IUwRVg7RVW0b4lmorFUvdD1Bob6rVNLSbSVYaie/2mw0pGgnv62F9tq/Lsx+ SCQwrX01qepAaQ63JYtK33nrm+i/T9rJn+2zuKSe2NXh6FSXAsBwbIgAvsy7T7I+yk8l S79qn7xUCJvme3JZ0NJg69JhtnT2wfuh8pVV7r43/8CQG+pIe+FnpmULKMM1R9ePrv/s SlSosOjU6v6brjXJ+cOlvkMYTRF6YfQiaZ1RbNHAH+lQJJ4eUq+x9r79tYTBK8tMxJNE H2urYfQOdYayiz1rVSFrcFGol7Jwz3BK0GvnMvB3A8x167GebkgxYEMAhOaKPBh8GcUe oSZA== X-Gm-Message-State: AOAM530gMlsJ437sH54FPlOHIYY2fFyJveX1dKr5nWP/il3d4khCrpAr vSTpS4LcPWZINoGxopT2984MW1E8OemMQQRjE++ornfWjek1L92cpHpBpCh4Ug8oeKoDmO29gAj reBihdfoMpO8DO/8QHjA6CHvG X-Received: by 2002:a17:907:2d10:b0:6db:e3f7:2cb2 with SMTP id gs16-20020a1709072d1000b006dbe3f72cb2mr7044458ejc.491.1647378290205; Tue, 15 Mar 2022 14:04:50 -0700 (PDT) X-Google-Smtp-Source: ABdhPJzFURJou0qHK3Ty0YITnet1XUuDQ4l0/RdLru/LNmM8UKD9zSw6Bk4nUOBNf8RjiKVC5dVhFQ== X-Received: by 2002:a17:907:2d10:b0:6db:e3f7:2cb2 with SMTP id gs16-20020a1709072d1000b006dbe3f72cb2mr7044438ejc.491.1647378289947; Tue, 15 Mar 2022 14:04:49 -0700 (PDT) Received: from ?IPV6:2001:b07:6468:f312:63a7:c72e:ea0e:6045? ([2001:b07:6468:f312:63a7:c72e:ea0e:6045]) by smtp.googlemail.com with ESMTPSA id s4-20020a170906a18400b006db0a78bde8sm64359ejy.87.2022.03.15.14.04.47 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 15 Mar 2022 14:04:49 -0700 (PDT) Message-ID: <87fe8fef-ab3c-6459-6494-06d3d74308a6@redhat.com> Date: Tue, 15 Mar 2022 22:04:46 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.5.0 Subject: Re: [PATCH V2 4/5] KVM: X86: Handle implicit supervisor access with SMAP Content-Language: en-US To: Lai Jiangshan , linux-kernel@vger.kernel.org, kvm@vger.kernel.org, Sean Christopherson Cc: Lai Jiangshan , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" References: <20220311070346.45023-1-jiangshanlai@gmail.com> <20220311070346.45023-5-jiangshanlai@gmail.com> From: Paolo Bonzini In-Reply-To: <20220311070346.45023-5-jiangshanlai@gmail.com> 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 3/11/22 08:03, Lai Jiangshan wrote: > - unsigned long not_smap = (cpl - 3) & (rflags & X86_EFLAGS_AC); > - int index = (pfec >> 1) + > - (not_smap >> (X86_EFLAGS_AC_BIT - PFERR_RSVD_BIT + 1)); > + bool explicit_access = !(access & PFERR_IMPLICIT_ACCESS); > + bool not_smap = (rflags & X86_EFLAGS_AC) && explicit_access; > + int index = (pfec + (!!not_smap << PFERR_RSVD_BIT)) >> 1; Also possible: u64 implicit_access = access & PFERR_IMPLICIT_ACCESS; bool not_smap = ((rflags & X86_EFLAGS_AC) | implicit_access) == X86_EFLAGS_AC; int index = (pfec + (not_smap << PFERR_RSVD_BIT)) >> 1; Paolo