From patchwork Fri Aug 6 00:16:57 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jarkko Sakkinen X-Patchwork-Id: 12422397 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=unavailable 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 3893EC4320A for ; Fri, 6 Aug 2021 00:17:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1718761165 for ; Fri, 6 Aug 2021 00:17:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232808AbhHFAR2 (ORCPT ); Thu, 5 Aug 2021 20:17:28 -0400 Received: from mail.kernel.org ([198.145.29.99]:41536 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231253AbhHFAR2 (ORCPT ); Thu, 5 Aug 2021 20:17:28 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id CA25E61164; Fri, 6 Aug 2021 00:17:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1628209033; bh=defyoJDmegfMyeFnTrjoa+8oq8G0jbIQzX8vKY3OKZU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=dwtd4yWqnJ5Rx5Er8eZcWMCoJ0IRjKudBJFW/nlQgIQI6qKuc3Ev11FGKoF8NJF3q Pj2GtkDSbkb5fm3yR056Tn/8OcyYRmaF4hJE8PyFe3lUCOdBbZ2wbUVRSNHK2pR4B9 nblnc1/XI7xQao2+/zE4MUmOM8YNJ7FmbTasr98H5CJuaxXY60TKxxFoN9rnf3wRxS 1P/H9Iig8vBkW4ITUyeJpEedSc5SUXuQStz032xiTVaNt+XWJ2DNyJEtDnHNOHhWhX 8uEbD9/Ak+FZDUoIys3m2ou7sublYIHD6ZjQb2RSvE3YPN5w8Sx9y8leT4IKrXUW/b FOjMKa1wcyUww== 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 v3 1/8] x86/sgx: Add /sys/kernel/debug/x86/sgx_total_mem Date: Fri, 6 Aug 2021 03:16:57 +0300 Message-Id: <20210806001704.667889-2-jarkko@kernel.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210806001704.667889-1-jarkko@kernel.org> References: <20210806001704.667889-1-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: