Received: by 2002:a05:6a10:206:0:0:0:0 with SMTP id 6csp1683164pxj; Wed, 19 May 2021 11:22:57 -0700 (PDT) X-Google-Smtp-Source: ABdhPJy+C+s8EdpQ/S73LVTbNTN7gftqEBBhCwR5+CZmA/OawU4Su7wyxQmdzPB39CokmucuTWaG X-Received: by 2002:a05:6638:635:: with SMTP id h21mr248069jar.135.1621448577835; Wed, 19 May 2021 11:22:57 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1621448577; cv=none; d=google.com; s=arc-20160816; b=DxtP4zFNFJcssNk7tJGYkmQO8NoKVTLipP5xJq4maIZtP12ibQSbpn3kNbOfy74qP3 aeHcC5l6u0l5remH1be/JtkKomIxUTjTMdlIwvVJDSyMYZW3Yb5kmgkgcRknSxuG29W1 GYxXBaAwFDUjUXJOLr3+WWawKC3xCgs7nNjFKEmbrJn9TaoVHFUvYC8PkJy3WUTKL7y4 UD5Jx+d48Hp6nS2z6j8VPPA7b4HbluqI5jIUAMd5uaHo65sigSK0boEyDRckvNefPD9a 82CShmYDJWxUYQKjFKFZln6lqsOeAAwETPJ+rconuWhkSu2QzC6iE7JdcM0YrRJ8sElz hdLw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:content-language :in-reply-to:mime-version:user-agent:date:message-id:autocrypt:from :references:cc:to:subject:ironport-sdr:ironport-sdr; bh=uon3FVHwujUsvfqsL4ucy/G6X6hJZpNfl7fwOLM0x0I=; b=n7cn3wmODyHrBZ9LfqZhy81CyZ6UWneZJuyLhKglz7igTJc0YB3eWeOxEEUlCF/7RO jNChw3D52gP/mjDc2q56ZpLp7YKwNgPHkS2tf7h1gKCVlVXAbRE+4OGrzQlUrhXEXd6z NqkHFzNYIWVWCLikG3xwe16txju29Ap5BDMnSGQtB5d1lXO1e4VzBPhoUXeVp+6S/S+s 9vnHS6LsVLygEJXtdbMfJIqJo6pAfXPOCLH6AxrlqmNmdeCDo6+m92d4C9aZzKRhhT8k Xy3GPLQevUJsfnfw8yLSIxH4kGLzQAyDwHWazaKwCFHhDrGd96uSWteAFtHFCs2NXWFK 3X2Q== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=intel.com Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id s4si36686jan.21.2021.05.19.11.22.44; Wed, 19 May 2021 11:22:57 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=intel.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1350598AbhERQZt (ORCPT + 99 others); Tue, 18 May 2021 12:25:49 -0400 Received: from mga05.intel.com ([192.55.52.43]:43110 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237986AbhERQZt (ORCPT ); Tue, 18 May 2021 12:25:49 -0400 IronPort-SDR: X6KxYBgrrrUKPZHSfuvZ+2kdbgh1/BCt3pph81KYSVlzDjGM1txVCMd0k7Oo67Gr0d6V93R6y0 Qmetjts2WrtA== X-IronPort-AV: E=McAfee;i="6200,9189,9988"; a="286286827" X-IronPort-AV: E=Sophos;i="5.82,310,1613462400"; d="scan'208";a="286286827" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 May 2021 09:22:43 -0700 IronPort-SDR: d+jPaCyYCZzJgMzW/VRYZIqFvZoZfCoQCgHUtzfUf3LrAmntCBxjNJAOxm/dKZ8PaZTzF1tLUt r5GlNdeCoItg== X-IronPort-AV: E=Sophos;i="5.82,310,1613462400"; d="scan'208";a="542034251" Received: from craigsmi-mobl.amr.corp.intel.com (HELO [10.212.132.228]) ([10.212.132.228]) by fmsmga001-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 May 2021 09:22:42 -0700 Subject: Re: [RFC v2-fix 1/1] x86/tdx: Handle in-kernel MMIO To: Andi Kleen , Kuppuswamy Sathyanarayanan , Peter Zijlstra , Andy Lutomirski Cc: Tony Luck , Kirill Shutemov , Kuppuswamy Sathyanarayanan , Dan Williams , Raj Ashok , Sean Christopherson , linux-kernel@vger.kernel.org References: <3e9a26c3-8eee-88f5-f8e2-8a2dd2c028ea@intel.com> <20210518004807.258503-1-sathyanarayanan.kuppuswamy@linux.intel.com> <36cd2665-6d8b-9c0b-eec1-25152dcca2a3@intel.com> <43e583a3-ee2b-52d8-5275-e26a6609c126@linux.intel.com> <94dc5a5a-8c51-8624-5810-e6278783789c@intel.com> From: Dave Hansen Autocrypt: addr=dave.hansen@intel.com; keydata= xsFNBE6HMP0BEADIMA3XYkQfF3dwHlj58Yjsc4E5y5G67cfbt8dvaUq2fx1lR0K9h1bOI6fC oAiUXvGAOxPDsB/P6UEOISPpLl5IuYsSwAeZGkdQ5g6m1xq7AlDJQZddhr/1DC/nMVa/2BoY 2UnKuZuSBu7lgOE193+7Uks3416N2hTkyKUSNkduyoZ9F5twiBhxPJwPtn/wnch6n5RsoXsb ygOEDxLEsSk/7eyFycjE+btUtAWZtx+HseyaGfqkZK0Z9bT1lsaHecmB203xShwCPT49Blxz VOab8668QpaEOdLGhtvrVYVK7x4skyT3nGWcgDCl5/Vp3TWA4K+IofwvXzX2ON/Mj7aQwf5W iC+3nWC7q0uxKwwsddJ0Nu+dpA/UORQWa1NiAftEoSpk5+nUUi0WE+5DRm0H+TXKBWMGNCFn c6+EKg5zQaa8KqymHcOrSXNPmzJuXvDQ8uj2J8XuzCZfK4uy1+YdIr0yyEMI7mdh4KX50LO1 pmowEqDh7dLShTOif/7UtQYrzYq9cPnjU2ZW4qd5Qz2joSGTG9eCXLz5PRe5SqHxv6ljk8mb ApNuY7bOXO/A7T2j5RwXIlcmssqIjBcxsRRoIbpCwWWGjkYjzYCjgsNFL6rt4OL11OUF37wL QcTl7fbCGv53KfKPdYD5hcbguLKi/aCccJK18ZwNjFhqr4MliQARAQABzShEYXZpZCBDaHJp c3RvcGhlciBIYW5zZW4gPGRhdmVAc3I3MS5uZXQ+wsF7BBMBAgAlAhsDBgsJCAcDAgYVCAIJ CgsEFgIDAQIeAQIXgAUCTo3k0QIZAQAKCRBoNZUwcMmSsMO2D/421Xg8pimb9mPzM5N7khT0 2MCnaGssU1T59YPE25kYdx2HntwdO0JA27Wn9xx5zYijOe6B21ufrvsyv42auCO85+oFJWfE K2R/IpLle09GDx5tcEmMAHX6KSxpHmGuJmUPibHVbfep2aCh9lKaDqQR07gXXWK5/yU1Dx0r VVFRaHTasp9fZ9AmY4K9/BSA3VkQ8v3OrxNty3OdsrmTTzO91YszpdbjjEFZK53zXy6tUD2d e1i0kBBS6NLAAsqEtneplz88T/v7MpLmpY30N9gQU3QyRC50jJ7LU9RazMjUQY1WohVsR56d ORqFxS8ChhyJs7BI34vQusYHDTp6PnZHUppb9WIzjeWlC7Jc8lSBDlEWodmqQQgp5+6AfhTD kDv1a+W5+ncq+Uo63WHRiCPuyt4di4/0zo28RVcjtzlGBZtmz2EIC3vUfmoZbO/Gn6EKbYAn rzz3iU/JWV8DwQ+sZSGu0HmvYMt6t5SmqWQo/hyHtA7uF5Wxtu1lCgolSQw4t49ZuOyOnQi5 f8R3nE7lpVCSF1TT+h8kMvFPv3VG7KunyjHr3sEptYxQs4VRxqeirSuyBv1TyxT+LdTm6j4a mulOWf+YtFRAgIYyyN5YOepDEBv4LUM8Tz98lZiNMlFyRMNrsLV6Pv6SxhrMxbT6TNVS5D+6 UorTLotDZKp5+M7BTQRUY85qARAAsgMW71BIXRgxjYNCYQ3Xs8k3TfAvQRbHccky50h99TUY sqdULbsb3KhmY29raw1bgmyM0a4DGS1YKN7qazCDsdQlxIJp9t2YYdBKXVRzPCCsfWe1dK/q 66UVhRPP8EGZ4CmFYuPTxqGY+dGRInxCeap/xzbKdvmPm01Iw3YFjAE4PQ4hTMr/H76KoDbD cq62U50oKC83ca/PRRh2QqEqACvIH4BR7jueAZSPEDnzwxvVgzyeuhwqHY05QRK/wsKuhq7s UuYtmN92Fasbxbw2tbVLZfoidklikvZAmotg0dwcFTjSRGEg0Gr3p/xBzJWNavFZZ95Rj7Et db0lCt0HDSY5q4GMR+SrFbH+jzUY/ZqfGdZCBqo0cdPPp58krVgtIGR+ja2Mkva6ah94/oQN lnCOw3udS+Eb/aRcM6detZr7XOngvxsWolBrhwTQFT9D2NH6ryAuvKd6yyAFt3/e7r+HHtkU kOy27D7IpjngqP+b4EumELI/NxPgIqT69PQmo9IZaI/oRaKorYnDaZrMXViqDrFdD37XELwQ gmLoSm2VfbOYY7fap/AhPOgOYOSqg3/Nxcapv71yoBzRRxOc4FxmZ65mn+q3rEM27yRztBW9 AnCKIc66T2i92HqXCw6AgoBJRjBkI3QnEkPgohQkZdAb8o9WGVKpfmZKbYBo4pEAEQEAAcLB XwQYAQIACQUCVGPOagIbDAAKCRBoNZUwcMmSsJeCEACCh7P/aaOLKWQxcnw47p4phIVR6pVL e4IEdR7Jf7ZL00s3vKSNT+nRqdl1ugJx9Ymsp8kXKMk9GSfmZpuMQB9c6io1qZc6nW/3TtvK pNGz7KPPtaDzvKA4S5tfrWPnDr7n15AU5vsIZvgMjU42gkbemkjJwP0B1RkifIK60yQqAAlT YZ14P0dIPdIPIlfEPiAWcg5BtLQU4Wg3cNQdpWrCJ1E3m/RIlXy/2Y3YOVVohfSy+4kvvYU3 lXUdPb04UPw4VWwjcVZPg7cgR7Izion61bGHqVqURgSALt2yvHl7cr68NYoFkzbNsGsye9ft M9ozM23JSgMkRylPSXTeh5JIK9pz2+etco3AfLCKtaRVysjvpysukmWMTrx8QnI5Nn5MOlJj 1Ov4/50JY9pXzgIDVSrgy6LYSMc4vKZ3QfCY7ipLRORyalFDF3j5AGCMRENJjHPD6O7bl3Xo 4DzMID+8eucbXxKiNEbs21IqBZbbKdY1GkcEGTE7AnkA3Y6YB7I/j9mQ3hCgm5muJuhM/2Fr OPsw5tV/LmQ5GXH0JQ/TZXWygyRFyyI2FqNTx4WHqUn3yFj8rwTAU1tluRUYyeLy0ayUlKBH ybj0N71vWO936MqP6haFERzuPAIpxj2ezwu0xb1GjTk4ynna6h5GjnKgdfOWoRtoWndMZxbA z5cecg== Message-ID: Date: Tue, 18 May 2021 09:22:40 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 5/18/21 9:10 AM, Andi Kleen wrote: > I'm not aware of any other places that would do MMIO without using the > standard io.h macros, although it might happen in theory on x86 (but > would likely break on some other architectures) Can we please connect all of the dots and turn this into a coherent changelog? * In-kernel MMIO is handled via exceptions (#VE) and instruction cracking * Arbitrary MMIO instructions are not handled (and would result in...) * The limited set of MMIO instructions that are handled are known and come from the io.h macros, ultimately build_mmio_read/write(). * This approach is also used for SEV-ES??? * Some x86 code that avoids the MMIO code is known to exist (APIC). But, this code is not used in TDX guests BTW, in perusing arch/x86/include/asm/io.h, I was reminded of movdir64b. That seems like one we'd want to take care of sooner rather than later. Or, do we expect the first folks who expose a movdir64b-using driver to TDX to go and update this code? Also, the sev_key_active() stuff in there makes me nervous. Does this scheme work with these: > static inline void outs##bwl(int port, const void *addr, unsigned long count) \ > static inline void ins##bwl(int port, void *addr, unsigned long count) \ ?