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=-5.8 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 BF06EC43216 for ; Wed, 28 Jul 2021 13:19:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A5B1D6101B for ; Wed, 28 Jul 2021 13:19:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236153AbhG1NTT (ORCPT ); Wed, 28 Jul 2021 09:19:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50768 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234771AbhG1NTS (ORCPT ); Wed, 28 Jul 2021 09:19:18 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8295AC061757; Wed, 28 Jul 2021 06:19:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=bU/Ms46JtnXaVrVhQUyi3qsSgcv2ZUBgkJZ69baP/Pk=; b=l/t/Xn+txpO1+X8wtS8Uk4aaqG m2+T0SHpVqEnt0/9mZr65K2ueB1kLi0Gx/E9Ov/NZNfcfbm0aSIoCXUBZDMdD7FMkHtRpiECduJr7 Rt4ArgG6CcLFJpfB7mhR9ochKMyUK4sUQhYvpLwmW49Gs9J06Mvyg5y94GM6d6rLaXR9BaAbWOIpZ 10T8RMs/K27IkXLp/vjCX+SQ8wtLiH+hDMOJw4D/h2g1l8zP6PGPE8V75qPmB6DklI1zsDwON4VTT tuN/D97KN3CBoRNqQG3rooTGaJ8SPBZlGmhA5MCb/K3ZPko/3eWBLi9x75g/uvwD+FrvCC64M+RgR Pk0dHV9A==; Received: from hch by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1m8jR9-00G4xh-78; Wed, 28 Jul 2021 13:17:52 +0000 Date: Wed, 28 Jul 2021 14:17:27 +0100 From: Christoph Hellwig To: Tom Lendacky Cc: linux-kernel@vger.kernel.org, x86@kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, iommu@lists.linux-foundation.org, kvm@vger.kernel.org, linux-efi@vger.kernel.org, platform-driver-x86@vger.kernel.org, linux-graphics-maintainer@vmware.com, amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, kexec@lists.infradead.org, linux-fsdevel@vger.kernel.org, Andi Kleen , Tianyu Lan , Borislav Petkov , Brijesh Singh Subject: Re: [PATCH 01/11] mm: Introduce a function to check for virtualization protection features Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jul 27, 2021 at 05:26:04PM -0500, Tom Lendacky via iommu wrote: > In prep for other protected virtualization technologies, introduce a > generic helper function, prot_guest_has(), that can be used to check > for specific protection attributes, like memory encryption. This is > intended to eliminate having to add multiple technology-specific checks > to the code (e.g. if (sev_active() || tdx_active())). So common checks obviously make sense, but I really hate the stupid multiplexer. Having one well-documented helper per feature is much easier to follow. > +#define PATTR_MEM_ENCRYPT 0 /* Encrypted memory */ > +#define PATTR_HOST_MEM_ENCRYPT 1 /* Host encrypted memory */ > +#define PATTR_GUEST_MEM_ENCRYPT 2 /* Guest encrypted memory */ > +#define PATTR_GUEST_PROT_STATE 3 /* Guest encrypted state */ The kerneldoc comments on these individual helpers will give you plenty of space to properly document what they indicate and what a (potential) caller should do based on them. Something the above comments completely fail to. 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=-3.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED 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 6131BC4338F for ; Wed, 28 Jul 2021 13:20:47 +0000 (UTC) Received: from smtp1.osuosl.org (smtp1.osuosl.org [140.211.166.138]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 1562261019 for ; Wed, 28 Jul 2021 13:20:47 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 1562261019 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by smtp1.osuosl.org (Postfix) with ESMTP id C2F6F838E6; Wed, 28 Jul 2021 13:20:46 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp1.osuosl.org ([127.0.0.1]) by localhost (smtp1.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id K0ih80HRgfVX; Wed, 28 Jul 2021 13:20:45 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [IPv6:2605:bc80:3010:104::8cd3:938]) by smtp1.osuosl.org (Postfix) with ESMTPS id 95B16836A7; Wed, 28 Jul 2021 13:20:45 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 7A8F1C001A; Wed, 28 Jul 2021 13:20:45 +0000 (UTC) Received: from smtp2.osuosl.org (smtp2.osuosl.org [IPv6:2605:bc80:3010::133]) by lists.linuxfoundation.org (Postfix) with ESMTP id D80AAC000E for ; Wed, 28 Jul 2021 13:20:42 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp2.osuosl.org (Postfix) with ESMTP id 1D752401C7 for ; Wed, 28 Jul 2021 13:20:04 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Authentication-Results: smtp2.osuosl.org (amavisd-new); dkim=pass (2048-bit key) header.d=infradead.org Received: from smtp2.osuosl.org ([127.0.0.1]) by localhost (smtp2.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id RNZyw7XItAlq for ; Wed, 28 Jul 2021 13:20:01 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.8.0 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by smtp2.osuosl.org (Postfix) with ESMTPS id 8781E4017A for ; Wed, 28 Jul 2021 13:20:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=bU/Ms46JtnXaVrVhQUyi3qsSgcv2ZUBgkJZ69baP/Pk=; b=l/t/Xn+txpO1+X8wtS8Uk4aaqG m2+T0SHpVqEnt0/9mZr65K2ueB1kLi0Gx/E9Ov/NZNfcfbm0aSIoCXUBZDMdD7FMkHtRpiECduJr7 Rt4ArgG6CcLFJpfB7mhR9ochKMyUK4sUQhYvpLwmW49Gs9J06Mvyg5y94GM6d6rLaXR9BaAbWOIpZ 10T8RMs/K27IkXLp/vjCX+SQ8wtLiH+hDMOJw4D/h2g1l8zP6PGPE8V75qPmB6DklI1zsDwON4VTT tuN/D97KN3CBoRNqQG3rooTGaJ8SPBZlGmhA5MCb/K3ZPko/3eWBLi9x75g/uvwD+FrvCC64M+RgR Pk0dHV9A==; Received: from hch by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1m8jR9-00G4xh-78; Wed, 28 Jul 2021 13:17:52 +0000 Date: Wed, 28 Jul 2021 14:17:27 +0100 From: Christoph Hellwig To: Tom Lendacky Subject: Re: [PATCH 01/11] mm: Introduce a function to check for virtualization protection features Message-ID: References: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html Cc: linux-s390@vger.kernel.org, linux-efi@vger.kernel.org, Tianyu Lan , kvm@vger.kernel.org, x86@kernel.org, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, amd-gfx@lists.freedesktop.org, platform-driver-x86@vger.kernel.org, iommu@lists.linux-foundation.org, Andi Kleen , linux-graphics-maintainer@vmware.com, dri-devel@lists.freedesktop.org, Brijesh Singh , linux-fsdevel@vger.kernel.org, Borislav Petkov , linuxppc-dev@lists.ozlabs.org X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" On Tue, Jul 27, 2021 at 05:26:04PM -0500, Tom Lendacky via iommu wrote: > In prep for other protected virtualization technologies, introduce a > generic helper function, prot_guest_has(), that can be used to check > for specific protection attributes, like memory encryption. This is > intended to eliminate having to add multiple technology-specific checks > to the code (e.g. if (sev_active() || tdx_active())). So common checks obviously make sense, but I really hate the stupid multiplexer. Having one well-documented helper per feature is much easier to follow. > +#define PATTR_MEM_ENCRYPT 0 /* Encrypted memory */ > +#define PATTR_HOST_MEM_ENCRYPT 1 /* Host encrypted memory */ > +#define PATTR_GUEST_MEM_ENCRYPT 2 /* Guest encrypted memory */ > +#define PATTR_GUEST_PROT_STATE 3 /* Guest encrypted state */ The kerneldoc comments on these individual helpers will give you plenty of space to properly document what they indicate and what a (potential) caller should do based on them. Something the above comments completely fail to. _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu 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=-3.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,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 A15F6C4338F for ; Wed, 28 Jul 2021 13:20:38 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 1C74E61019 for ; Wed, 28 Jul 2021 13:20:38 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 1C74E61019 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=lists.ozlabs.org Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4GZZ6D4KNvz3cbN for ; Wed, 28 Jul 2021 23:20:36 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; secure) header.d=infradead.org header.i=@infradead.org header.a=rsa-sha256 header.s=casper.20170209 header.b=l/t/Xn+t; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=none (no SPF record) smtp.mailfrom=casper.srs.infradead.org (client-ip=2001:8b0:10b:1236::1; helo=casper.infradead.org; envelope-from=batv+0bc2c65ec7bce8a447c4+6548+infradead.org+hch@casper.srs.infradead.org; receiver=) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; secure) header.d=infradead.org header.i=@infradead.org header.a=rsa-sha256 header.s=casper.20170209 header.b=l/t/Xn+t; dkim-atps=neutral Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4GZZ5d3S3mz2yxl for ; Wed, 28 Jul 2021 23:20:02 +1000 (AEST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=bU/Ms46JtnXaVrVhQUyi3qsSgcv2ZUBgkJZ69baP/Pk=; b=l/t/Xn+txpO1+X8wtS8Uk4aaqG m2+T0SHpVqEnt0/9mZr65K2ueB1kLi0Gx/E9Ov/NZNfcfbm0aSIoCXUBZDMdD7FMkHtRpiECduJr7 Rt4ArgG6CcLFJpfB7mhR9ochKMyUK4sUQhYvpLwmW49Gs9J06Mvyg5y94GM6d6rLaXR9BaAbWOIpZ 10T8RMs/K27IkXLp/vjCX+SQ8wtLiH+hDMOJw4D/h2g1l8zP6PGPE8V75qPmB6DklI1zsDwON4VTT tuN/D97KN3CBoRNqQG3rooTGaJ8SPBZlGmhA5MCb/K3ZPko/3eWBLi9x75g/uvwD+FrvCC64M+RgR Pk0dHV9A==; Received: from hch by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1m8jR9-00G4xh-78; Wed, 28 Jul 2021 13:17:52 +0000 Date: Wed, 28 Jul 2021 14:17:27 +0100 From: Christoph Hellwig To: Tom Lendacky Subject: Re: [PATCH 01/11] mm: Introduce a function to check for virtualization protection features Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-s390@vger.kernel.org, linux-efi@vger.kernel.org, Tianyu Lan , kvm@vger.kernel.org, x86@kernel.org, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, amd-gfx@lists.freedesktop.org, platform-driver-x86@vger.kernel.org, iommu@lists.linux-foundation.org, Andi Kleen , linux-graphics-maintainer@vmware.com, dri-devel@lists.freedesktop.org, Brijesh Singh , linux-fsdevel@vger.kernel.org, Borislav Petkov , linuxppc-dev@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Tue, Jul 27, 2021 at 05:26:04PM -0500, Tom Lendacky via iommu wrote: > In prep for other protected virtualization technologies, introduce a > generic helper function, prot_guest_has(), that can be used to check > for specific protection attributes, like memory encryption. This is > intended to eliminate having to add multiple technology-specific checks > to the code (e.g. if (sev_active() || tdx_active())). So common checks obviously make sense, but I really hate the stupid multiplexer. Having one well-documented helper per feature is much easier to follow. > +#define PATTR_MEM_ENCRYPT 0 /* Encrypted memory */ > +#define PATTR_HOST_MEM_ENCRYPT 1 /* Host encrypted memory */ > +#define PATTR_GUEST_MEM_ENCRYPT 2 /* Guest encrypted memory */ > +#define PATTR_GUEST_PROT_STATE 3 /* Guest encrypted state */ The kerneldoc comments on these individual helpers will give you plenty of space to properly document what they indicate and what a (potential) caller should do based on them. Something the above comments completely fail to. 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=-3.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED 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 AAF52C4338F for ; Wed, 28 Jul 2021 13:24:26 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 7B89E61019 for ; Wed, 28 Jul 2021 13:24:26 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 7B89E61019 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 1F6646E8BE; Wed, 28 Jul 2021 13:24:26 +0000 (UTC) Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by gabe.freedesktop.org (Postfix) with ESMTPS id 519D16E8BE; Wed, 28 Jul 2021 13:20:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=bU/Ms46JtnXaVrVhQUyi3qsSgcv2ZUBgkJZ69baP/Pk=; b=l/t/Xn+txpO1+X8wtS8Uk4aaqG m2+T0SHpVqEnt0/9mZr65K2ueB1kLi0Gx/E9Ov/NZNfcfbm0aSIoCXUBZDMdD7FMkHtRpiECduJr7 Rt4ArgG6CcLFJpfB7mhR9ochKMyUK4sUQhYvpLwmW49Gs9J06Mvyg5y94GM6d6rLaXR9BaAbWOIpZ 10T8RMs/K27IkXLp/vjCX+SQ8wtLiH+hDMOJw4D/h2g1l8zP6PGPE8V75qPmB6DklI1zsDwON4VTT tuN/D97KN3CBoRNqQG3rooTGaJ8SPBZlGmhA5MCb/K3ZPko/3eWBLi9x75g/uvwD+FrvCC64M+RgR Pk0dHV9A==; Received: from hch by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1m8jR9-00G4xh-78; Wed, 28 Jul 2021 13:17:52 +0000 Date: Wed, 28 Jul 2021 14:17:27 +0100 From: Christoph Hellwig To: Tom Lendacky Subject: Re: [PATCH 01/11] mm: Introduce a function to check for virtualization protection features Message-ID: References: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html X-Mailman-Approved-At: Wed, 28 Jul 2021 13:24:24 +0000 X-BeenThere: amd-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Discussion list for AMD gfx List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-s390@vger.kernel.org, linux-efi@vger.kernel.org, Tianyu Lan , kvm@vger.kernel.org, x86@kernel.org, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, amd-gfx@lists.freedesktop.org, platform-driver-x86@vger.kernel.org, iommu@lists.linux-foundation.org, Andi Kleen , linux-graphics-maintainer@vmware.com, dri-devel@lists.freedesktop.org, Brijesh Singh , linux-fsdevel@vger.kernel.org, Borislav Petkov , linuxppc-dev@lists.ozlabs.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: amd-gfx-bounces@lists.freedesktop.org Sender: "amd-gfx" On Tue, Jul 27, 2021 at 05:26:04PM -0500, Tom Lendacky via iommu wrote: > In prep for other protected virtualization technologies, introduce a > generic helper function, prot_guest_has(), that can be used to check > for specific protection attributes, like memory encryption. This is > intended to eliminate having to add multiple technology-specific checks > to the code (e.g. if (sev_active() || tdx_active())). So common checks obviously make sense, but I really hate the stupid multiplexer. Having one well-documented helper per feature is much easier to follow. > +#define PATTR_MEM_ENCRYPT 0 /* Encrypted memory */ > +#define PATTR_HOST_MEM_ENCRYPT 1 /* Host encrypted memory */ > +#define PATTR_GUEST_MEM_ENCRYPT 2 /* Guest encrypted memory */ > +#define PATTR_GUEST_PROT_STATE 3 /* Guest encrypted state */ The kerneldoc comments on these individual helpers will give you plenty of space to properly document what they indicate and what a (potential) caller should do based on them. Something the above comments completely fail to. _______________________________________________ amd-gfx mailing list amd-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/amd-gfx From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Date: Wed, 28 Jul 2021 14:17:27 +0100 From: Christoph Hellwig Subject: Re: [PATCH 01/11] mm: Introduce a function to check for virtualization protection features Message-ID: References: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kexec" Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: Tom Lendacky Cc: linux-kernel@vger.kernel.org, x86@kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, iommu@lists.linux-foundation.org, kvm@vger.kernel.org, linux-efi@vger.kernel.org, platform-driver-x86@vger.kernel.org, linux-graphics-maintainer@vmware.com, amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, kexec@lists.infradead.org, linux-fsdevel@vger.kernel.org, Andi Kleen , Tianyu Lan , Borislav Petkov , Brijesh Singh On Tue, Jul 27, 2021 at 05:26:04PM -0500, Tom Lendacky via iommu wrote: > In prep for other protected virtualization technologies, introduce a > generic helper function, prot_guest_has(), that can be used to check > for specific protection attributes, like memory encryption. This is > intended to eliminate having to add multiple technology-specific checks > to the code (e.g. if (sev_active() || tdx_active())). So common checks obviously make sense, but I really hate the stupid multiplexer. Having one well-documented helper per feature is much easier to follow. > +#define PATTR_MEM_ENCRYPT 0 /* Encrypted memory */ > +#define PATTR_HOST_MEM_ENCRYPT 1 /* Host encrypted memory */ > +#define PATTR_GUEST_MEM_ENCRYPT 2 /* Guest encrypted memory */ > +#define PATTR_GUEST_PROT_STATE 3 /* Guest encrypted state */ The kerneldoc comments on these individual helpers will give you plenty of space to properly document what they indicate and what a (potential) caller should do based on them. Something the above comments completely fail to. _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec