From patchwork Mon Aug 9 09:31:20 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jarkko Sakkinen X-Patchwork-Id: 12426017 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=-19.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,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 5D96AC4338F for ; Mon, 9 Aug 2021 09:31:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3AF8461056 for ; Mon, 9 Aug 2021 09:31:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234500AbhHIJb5 (ORCPT ); Mon, 9 Aug 2021 05:31:57 -0400 Received: from mail.kernel.org ([198.145.29.99]:42596 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234368AbhHIJb5 (ORCPT ); Mon, 9 Aug 2021 05:31:57 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id B27946101D; Mon, 9 Aug 2021 09:31:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1628501497; bh=mWQKQI8yAbXJt5cw/cLvAtRqYeiZGxdgd577VLR7NkU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KpSEOer/OkpU7r6DV1KoKKhSCqIU4pMP+/lGcx8JhRMC3E1esRD9uB6ECI77bygeZ H3x/10Dui32Fwd3ruyysS1gE3T/pA52msj7Id2xDBFoDuJGAecxcw36/wnS1EHa+JN hvLgPnAoqUtHDfKYF66HyIEydCU76nAs60EtXMgEIBeD1TdlmeBWl0nBJAA/p6O9jN NbcsdHoddzZmMUiQtT1f2BWRXoptyPDaxycbCNtAsqmludHan3Ru9p8GosS0ivrIYM GGtI/2xs5a4W0Anw8Wllz5iNwPR13fr9+teVuWbA1DZ/sy9Mf6rw/2orU0F73+GJel IyQ/BVDolaBSQ== From: Jarkko Sakkinen To: Shuah Khan Cc: linux-kselftest@vger.kernel.org, linux-sgx@vger.kernel.org, Reinette Chatre , Borislav Petkov , Jarkko Sakkinen , Dave Hansen , Thomas Gleixner , Ingo Molnar , x86@kernel.org, "H. Peter Anvin" , Jonathan Corbet , linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org Subject: [PATCH v4 1/8] x86/sgx: Add /sys/kernel/debug/x86/sgx_total_mem Date: Mon, 9 Aug 2021 12:31:20 +0300 Message-Id: <20210809093127.76264-2-jarkko@kernel.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210809093127.76264-1-jarkko@kernel.org> References: <20210809093127.76264-1-jarkko@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org 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 --- v3: * Describe the units of sgx_total_mem in Dcumentation/x86/sgx.rst. * Rewrite of the commit message (suggested by Dave): https://lore.kernel.org/linux-sgx/5d3614af-2393-6744-9d85-7001241ca76e@intel.com/ v2: * sgx_nr_all_pages -> sgx_total_mem 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: