From patchwork Wed Sep 15 20:30:52 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Reinette Chatre X-Patchwork-Id: 512548 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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT 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 0E9E1C43217 for ; Wed, 15 Sep 2021 20:31:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EDD7E61157 for ; Wed, 15 Sep 2021 20:31:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231955AbhIOUce (ORCPT ); Wed, 15 Sep 2021 16:32:34 -0400 Received: from mga07.intel.com ([134.134.136.100]:13811 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231592AbhIOUcd (ORCPT ); Wed, 15 Sep 2021 16:32:33 -0400 X-IronPort-AV: E=McAfee;i="6200,9189,10108"; a="286109360" X-IronPort-AV: E=Sophos;i="5.85,296,1624345200"; d="scan'208";a="286109360" Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Sep 2021 13:31:13 -0700 X-IronPort-AV: E=Sophos;i="5.85,296,1624345200"; d="scan'208";a="545092774" Received: from rchatre-ws.ostc.intel.com ([10.54.69.144]) by fmsmga003-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Sep 2021 13:31:13 -0700 From: Reinette Chatre To: linux-sgx@vger.kernel.org, jarkko@kernel.org, shuah@kernel.org Cc: seanjc@google.com, bp@alien8.de, dave.hansen@linux.intel.com, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 02/14] x86/sgx: Add /sys/kernel/debug/x86/sgx_total_mem Date: Wed, 15 Sep 2021 13:30:52 -0700 Message-Id: <086aa5a16faf0d9b47ba9e0ebd2213713d0e76ff.1631731214.git.reinette.chatre@intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org From: Jarkko Sakkinen Just like normal memory, SGX memory can be overcommitted. SGX has its own reclaim mechanism which kicks in when physical SGX memory (Enclave Page Cache / EPC) is exhausted. That reclaim mechanism is relatively rarely exercised and needs selftests to poke at it. The amount of EPC on the system is determined by the BIOS and it varies wildly between systems. It can be dozens of MB on desktops, or many GB on servers. To run in a reasonable amount of time, the selftest needs to know how much EPC there is in the system. Introduce a new debugfs file to export that information. Acked-by: Dave Hansen Signed-off-by: Jarkko Sakkinen [reinette: Use as placeholder patch until other discussions complete] Signed-off-by: Reinette Chatre --- Documentation/x86/sgx.rst | 6 ++++++ arch/x86/kernel/cpu/sgx/main.c | 10 +++++++++- 2 files changed, 15 insertions(+), 1 deletion(-) diff --git a/Documentation/x86/sgx.rst b/Documentation/x86/sgx.rst index dd0ac96ff9ef..f11bfb331b93 100644 --- a/Documentation/x86/sgx.rst +++ b/Documentation/x86/sgx.rst @@ -250,3 +250,9 @@ user wants to deploy SGX applications both on the host and in guests on the same machine, the user should reserve enough EPC (by taking out total virtual EPC size of all SGX VMs from the physical EPC size) for host SGX applications so they can run with acceptable performance. + +Debugging +========= + +*/sys/kernel/debug/x86/sgx_total_mem* contains an integer describing +the total SGX reserved memory in bytes, available in the system. diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c index 63d3de02bbcc..b65da19a53ee 100644 --- a/arch/x86/kernel/cpu/sgx/main.c +++ b/arch/x86/kernel/cpu/sgx/main.c @@ -1,6 +1,7 @@ // SPDX-License-Identifier: GPL-2.0 /* Copyright(c) 2016-20 Intel Corporation. */ +#include #include #include #include @@ -28,7 +29,10 @@ static DECLARE_WAIT_QUEUE_HEAD(ksgxd_waitq); static LIST_HEAD(sgx_active_page_list); static DEFINE_SPINLOCK(sgx_reclaimer_lock); -/* The free page list lock protected variables prepend the lock. */ +/* Total EPC memory available in bytes. */ +static unsigned long sgx_total_mem; + +/* The number of free EPC pages in all nodes. */ static unsigned long sgx_nr_free_pages; /* Nodes with one or more EPC sections. */ @@ -656,6 +660,8 @@ static bool __init sgx_setup_epc_section(u64 phys_addr, u64 size, list_add_tail(§ion->pages[i].list, &sgx_dirty_page_list); } + sgx_total_mem += nr_pages * PAGE_SIZE; + return true; } @@ -823,6 +829,8 @@ static int __init sgx_init(void) if (sgx_vepc_init() && ret) goto err_provision; + debugfs_create_ulong("sgx_total_mem", 0444, arch_debugfs_dir, &sgx_total_mem); + return 0; err_provision: