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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham 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 1B738C433F5 for ; Tue, 28 Aug 2018 21:26:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BCF942084A for ; Tue, 28 Aug 2018 21:26:48 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BCF942084A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727368AbeH2BUS (ORCPT ); Tue, 28 Aug 2018 21:20:18 -0400 Received: from mga17.intel.com ([192.55.52.151]:53124 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726998AbeH2BUS (ORCPT ); Tue, 28 Aug 2018 21:20:18 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by fmsmga107.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 28 Aug 2018 14:26:46 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.53,300,1531810800"; d="scan'208";a="84166372" Received: from ray.jf.intel.com (HELO [10.54.74.132]) ([10.54.74.132]) by fmsmga004.fm.intel.com with ESMTP; 28 Aug 2018 14:26:36 -0700 Subject: Re: [PATCH v13 09/13] x86/sgx: Enclave Page Cache (EPC) memory manager To: Sean Christopherson References: <20180827185507.17087-1-jarkko.sakkinen@linux.intel.com> <20180827185507.17087-10-jarkko.sakkinen@linux.intel.com> <7c5df14e-3028-46b3-fe93-aa6ba8352317@intel.com> <20180828083540.GH15508@linux.intel.com> <132d309d-77e2-52ed-7251-abb2c80cdf49@intel.com> <20180828212244.GA29488@linux.intel.com> Cc: Jarkko Sakkinen , x86@kernel.org, platform-driver-x86@vger.kernel.org, nhorman@redhat.com, npmccallum@redhat.com, linux-sgx@vger.kernel.org, Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Suresh Siddha , Serge Ayoun , "open list:X86 ARCHITECTURE (32-BIT AND 64-BIT)" From: Dave Hansen Openpgp: preference=signencrypt 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: <81adf7e1-b9c2-e906-95a3-c6e08cbcc52a@intel.com> Date: Tue, 28 Aug 2018 14:26:36 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <20180828212244.GA29488@linux.intel.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08/28/2018 02:22 PM, Sean Christopherson wrote: > On Tue, Aug 28, 2018 at 07:07:33AM -0700, Dave Hansen wrote: >> On 08/28/2018 01:35 AM, Jarkko Sakkinen wrote: >>> On Mon, Aug 27, 2018 at 02:15:34PM -0700, Dave Hansen wrote: >>>> On 08/27/2018 11:53 AM, Jarkko Sakkinen wrote: >>>>> +struct sgx_epc_page_ops { >>>>> + bool (*get)(struct sgx_epc_page *epc_page); >>>>> + void (*put)(struct sgx_epc_page *epc_page); >>>>> + bool (*reclaim)(struct sgx_epc_page *epc_page); >>>>> + void (*block)(struct sgx_epc_page *epc_page); >>>>> + void (*write)(struct sgx_epc_page *epc_page); >>>>> +}; >>>> Why do we need a fancy, slow (retpoline'd) set of function pointers when >>>> we only have one user of these (the SGX driver)? >>> KVM has its own implementation for these operations. >> >> That belongs in the changelog. >> >> Also, where is the implementation? How can we assess this code that was >> built to create an abstraction without both of the users? > > I can provide an early preview of the KVM reclaim code, but honestly > I think that would do more harm than good. The VMX architecture for > EPC reclaim is complex, even for SGX standards. Opening that can of > worms would likely derail this discussion. That being said, this > abstraction isn't exactly what KVM will need, but it's pretty close > and gives us something to build on. Please remove the abstraction code. We don't introduce infrastructure which no one will use. From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: [PATCH v13 09/13] x86/sgx: Enclave Page Cache (EPC) memory manager To: Sean Christopherson References: <20180827185507.17087-1-jarkko.sakkinen@linux.intel.com> <20180827185507.17087-10-jarkko.sakkinen@linux.intel.com> <7c5df14e-3028-46b3-fe93-aa6ba8352317@intel.com> <20180828083540.GH15508@linux.intel.com> <132d309d-77e2-52ed-7251-abb2c80cdf49@intel.com> <20180828212244.GA29488@linux.intel.com> CC: Jarkko Sakkinen , , , , , , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Suresh Siddha , Serge Ayoun , "open list:X86 ARCHITECTURE (32-BIT AND 64-BIT)" From: Dave Hansen Message-ID: <81adf7e1-b9c2-e906-95a3-c6e08cbcc52a@intel.com> Date: Tue, 28 Aug 2018 14:26:36 -0700 In-Reply-To: <20180828212244.GA29488@linux.intel.com> Content-Type: text/plain; charset="utf-8" Return-Path: dave.hansen@intel.com MIME-Version: 1.0 List-ID: On 08/28/2018 02:22 PM, Sean Christopherson wrote: > On Tue, Aug 28, 2018 at 07:07:33AM -0700, Dave Hansen wrote: >> On 08/28/2018 01:35 AM, Jarkko Sakkinen wrote: >>> On Mon, Aug 27, 2018 at 02:15:34PM -0700, Dave Hansen wrote: >>>> On 08/27/2018 11:53 AM, Jarkko Sakkinen wrote: >>>>> +struct sgx_epc_page_ops { >>>>> + bool (*get)(struct sgx_epc_page *epc_page); >>>>> + void (*put)(struct sgx_epc_page *epc_page); >>>>> + bool (*reclaim)(struct sgx_epc_page *epc_page); >>>>> + void (*block)(struct sgx_epc_page *epc_page); >>>>> + void (*write)(struct sgx_epc_page *epc_page); >>>>> +}; >>>> Why do we need a fancy, slow (retpoline'd) set of function pointers when >>>> we only have one user of these (the SGX driver)? >>> KVM has its own implementation for these operations. >> >> That belongs in the changelog. >> >> Also, where is the implementation? How can we assess this code that was >> built to create an abstraction without both of the users? > > I can provide an early preview of the KVM reclaim code, but honestly > I think that would do more harm than good. The VMX architecture for > EPC reclaim is complex, even for SGX standards. Opening that can of > worms would likely derail this discussion. That being said, this > abstraction isn't exactly what KVM will need, but it's pretty close > and gives us something to build on. Please remove the abstraction code. We don't introduce infrastructure which no one will use. From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave Hansen Subject: Re: [PATCH v13 09/13] x86/sgx: Enclave Page Cache (EPC) memory manager Date: Tue, 28 Aug 2018 14:26:36 -0700 Message-ID: <81adf7e1-b9c2-e906-95a3-c6e08cbcc52a@intel.com> References: <20180827185507.17087-1-jarkko.sakkinen@linux.intel.com> <20180827185507.17087-10-jarkko.sakkinen@linux.intel.com> <7c5df14e-3028-46b3-fe93-aa6ba8352317@intel.com> <20180828083540.GH15508@linux.intel.com> <132d309d-77e2-52ed-7251-abb2c80cdf49@intel.com> <20180828212244.GA29488@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20180828212244.GA29488@linux.intel.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Sean Christopherson Cc: Jarkko Sakkinen , x86@kernel.org, platform-driver-x86@vger.kernel.org, nhorman@redhat.com, npmccallum@redhat.com, linux-sgx@vger.kernel.org, Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Suresh Siddha , Serge Ayoun , "open list:X86 ARCHITECTURE (32-BIT AND 64-BIT)" List-Id: platform-driver-x86.vger.kernel.org On 08/28/2018 02:22 PM, Sean Christopherson wrote: > On Tue, Aug 28, 2018 at 07:07:33AM -0700, Dave Hansen wrote: >> On 08/28/2018 01:35 AM, Jarkko Sakkinen wrote: >>> On Mon, Aug 27, 2018 at 02:15:34PM -0700, Dave Hansen wrote: >>>> On 08/27/2018 11:53 AM, Jarkko Sakkinen wrote: >>>>> +struct sgx_epc_page_ops { >>>>> + bool (*get)(struct sgx_epc_page *epc_page); >>>>> + void (*put)(struct sgx_epc_page *epc_page); >>>>> + bool (*reclaim)(struct sgx_epc_page *epc_page); >>>>> + void (*block)(struct sgx_epc_page *epc_page); >>>>> + void (*write)(struct sgx_epc_page *epc_page); >>>>> +}; >>>> Why do we need a fancy, slow (retpoline'd) set of function pointers when >>>> we only have one user of these (the SGX driver)? >>> KVM has its own implementation for these operations. >> >> That belongs in the changelog. >> >> Also, where is the implementation? How can we assess this code that was >> built to create an abstraction without both of the users? > > I can provide an early preview of the KVM reclaim code, but honestly > I think that would do more harm than good. The VMX architecture for > EPC reclaim is complex, even for SGX standards. Opening that can of > worms would likely derail this discussion. That being said, this > abstraction isn't exactly what KVM will need, but it's pretty close > and gives us something to build on. Please remove the abstraction code. We don't introduce infrastructure which no one will use.