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 5E776C001DC for ; Sat, 15 Jul 2023 06:28:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229729AbjGOGXh (ORCPT ); Sat, 15 Jul 2023 02:23:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54290 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229482AbjGOGXf (ORCPT ); Sat, 15 Jul 2023 02:23:35 -0400 Received: from jabberwock.ucw.cz (jabberwock.ucw.cz [46.255.230.98]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A73D4107; Fri, 14 Jul 2023 23:23:33 -0700 (PDT) Received: by jabberwock.ucw.cz (Postfix, from userid 1017) id F3F771C0DC0; Sat, 15 Jul 2023 08:23:30 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ucw.cz; s=gen1; t=1689402211; 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: in-reply-to:in-reply-to:references:references; bh=h3LfdKGs0UxPjzB0BynU4i+zXf5U8uBunZusMAra21g=; b=LSLSS9A97dd9uMgAE65BakTS7lZ91g6yS/VGEcPg9pI2t8StKF/F6T+gpZQX7xBPwT9bM7 3q5JmGTlicHewhE7yBDaIUWe2206dct+xIFvW7R2mBsEimcBXORu0a+STYjj2wyLiRRfq/ gm0rlVliRJ2WFoxFYEOHVEwJNN4zaag= Date: Sat, 15 Jul 2023 08:23:30 +0200 From: Pavel Machek To: Mario Limonciello Cc: Herbert Xu , linux-crypto@vger.kernel.org, Tom Lendacky , "David S . Miller" , John Allen , linux-kernel@vger.kernel.org Subject: Re: [PATCH 00/10] Add dynamic boost control support Message-ID: References: <20230420163140.14940-1-mario.limonciello@amd.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="ZvntLkCFVhX5QPPV" Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --ZvntLkCFVhX5QPPV Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed 2023-04-26 09:43:43, Mario Limonciello wrote: >=20 > On 4/26/23 08:47, Pavel Machek wrote: > > Hi! > >=20 > > > Dynamic boost control is a feature of some SoCs that allows > > > an authenticated entity to send commands to the security processor > > > to control certain SOC characteristics with the intention to improve > > > performance. > > >=20 > > > This is implemented via a mechanism that a userspace application would > > > authenticate using a nonce and key exchange over an IOCTL interface. > > >=20 > > > After authentication is complete an application can exchange signed > > > messages with the security processor and both ends can validate the > > > data transmitted. > > Why is this acceptable? This precludes cross-platform interfaces, > > right? Why would application want to validate data from PSP? That > > precludes virtualization, right? > >=20 > > Just put the key in kernel. Users have right to control their own > > hardware. > > Pavel >=20 > This matches exactly how the interface works in Windows as well. Windows has different design constrants. > The reason for validating the data from the PSP is because the data > crosses multiple trust boundaries and this ensures that the application > can trust it to make informed decisions. If the application can not trust kernel, you are already doomed on Linux. Pavel --=20 People of Russia, stop Putin before his war on Ukraine escalates. --ZvntLkCFVhX5QPPV Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iF0EABECAB0WIQRPfPO7r0eAhk010v0w5/Bqldv68gUCZLI7YgAKCRAw5/Bqldv6 8h10AJ9TRbzD34klcp52yn4ZUhUWuRE2nACdG7WaPnyMrL14KJu0Hm/iFjkn3IY= =NzZ5 -----END PGP SIGNATURE----- --ZvntLkCFVhX5QPPV--