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=-3.9 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS 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 B7966C433DF for ; Tue, 25 Aug 2020 11:04:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 90F2720715 for ; Tue, 25 Aug 2020 11:04:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=alien8.de header.i=@alien8.de header.b="bLUbdTQq" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729914AbgHYLEx (ORCPT ); Tue, 25 Aug 2020 07:04:53 -0400 Received: from mail.skyhub.de ([5.9.137.197]:54788 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729529AbgHYLEr (ORCPT ); Tue, 25 Aug 2020 07:04:47 -0400 Received: from zn.tnic (p200300ec2f0c5a0001535c65a93122e2.dip0.t-ipconnect.de [IPv6:2003:ec:2f0c:5a00:153:5c65:a931:22e2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id AEAED1EC0299; Tue, 25 Aug 2020 13:04:45 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1598353485; 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:in-reply-to:in-reply-to: references:references; bh=M3DtE2HDJMaftMHgyeELlhmPqaW7/VgBKsyLltgJBkY=; b=bLUbdTQqHXoJunltKk2lQ/8OSisXCWByt7CjiA/EG6fD8SiJ5w8owNkA/vwdkjt0o4JFdA hGvlX4TGZXnuGdSGbqcreYTAKxVCmwrnxnfiD+buOP9AE9EAlLGjP+eSW+W3udaoPbTYYn Xst5bBJiQsVyCEm46KyE3CCo0pkdJqA= Date: Tue, 25 Aug 2020 13:04:46 +0200 From: Borislav Petkov To: Joerg Roedel Cc: x86@kernel.org, Joerg Roedel , Tom Lendacky , hpa@zytor.com, Andy Lutomirski , Dave Hansen , Peter Zijlstra , Jiri Slaby , Dan Williams , Juergen Gross , Kees Cook , David Rientjes , Cfir Cohen , Erdem Aktas , Masami Hiramatsu , Mike Stunes , Sean Christopherson , Martin Radev , linux-kernel@vger.kernel.org, kvm@vger.kernel.org, virtualization@lists.linux-foundation.org Subject: Re: [PATCH v6 02/76] KVM: SVM: Add GHCB definitions Message-ID: <20200825110446.GC12107@zn.tnic> References: <20200824085511.7553-1-joro@8bytes.org> <20200824085511.7553-3-joro@8bytes.org> <20200824104451.GA4732@zn.tnic> <20200825092224.GF3319@8bytes.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20200825092224.GF3319@8bytes.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Aug 25, 2020 at 11:22:24AM +0200, Joerg Roedel wrote: > I don't think so, if I look at the history of these checks their whole > purpose seems to be to alert the developer/maintainer when their size > changes and that they might not fit on the stack anymore. But that is > taken care of in patch 1. Why? What's wrong with: BUILD_BUG_ON(sizeof(struct vmcb_save_area) != VMCB_SAVE_AREA_SIZE); BUILD_BUG_ON(sizeof(struct vmcb_control_area) != VMCB_CONTROL_AREA_SIZE); BUILD_BUG_ON(sizeof(struct ghcb) != PAGE_SIZE); ? -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette