From patchwork Sun Jan 24 06:29:05 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "tianjia.zhang" X-Patchwork-Id: 12042117 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,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 B3CE7C433DB for ; Sun, 24 Jan 2021 06:30:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 816FC22C9D for ; Sun, 24 Jan 2021 06:30:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726560AbhAXGak (ORCPT ); Sun, 24 Jan 2021 01:30:40 -0500 Received: from out30-43.freemail.mail.aliyun.com ([115.124.30.43]:42676 "EHLO out30-43.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726054AbhAXGah (ORCPT ); Sun, 24 Jan 2021 01:30:37 -0500 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R141e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04420;MF=tianjia.zhang@linux.alibaba.com;NM=1;PH=DS;RN=13;SR=0;TI=SMTPD_---0UMf9yuo_1611469749; Received: from localhost(mailfrom:tianjia.zhang@linux.alibaba.com fp:SMTPD_---0UMf9yuo_1611469749) by smtp.aliyun-inc.com(127.0.0.1); Sun, 24 Jan 2021 14:29:09 +0800 From: Tianjia Zhang To: Jarkko Sakkinen , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , Sean Christopherson , Shuah Khan , x86@kernel.org, linux-sgx@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, Jia Zhang Cc: Tianjia Zhang Subject: [PATCH v3 3/5] x86/sgx: Optimize the free_cnt count in sgx_epc_section Date: Sun, 24 Jan 2021 14:29:05 +0800 Message-Id: <20210124062907.88229-4-tianjia.zhang@linux.alibaba.com> X-Mailer: git-send-email 2.19.1.3.ge56e4f7 In-Reply-To: <20210124062907.88229-1-tianjia.zhang@linux.alibaba.com> References: <20210124062907.88229-1-tianjia.zhang@linux.alibaba.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org `section->free_cnt` represents the free page in sgx_epc_section, which is assigned once after initialization. In fact, just after the initialization is completed, the pages are in the `init_laundry_list` list and cannot be allocated. This needs to be recovered by EREMOVE of function sgx_sanitize_section() before it can be used as a page that can be allocated. The sgx_sanitize_section() will be called in the kernel thread ksgxd. This patch moves the initialization of `section->free_cnt` from the initialization function `sgx_setup_epc_section()` to the function `sgx_sanitize_section()`, and then accumulates the count after the successful execution of EREMOVE. This seems to be more reasonable, free_cnt will also truly reflect the allocatable free pages in EPC. Sined-off-by: Tianjia Zhang Reviewed-by: Sean Christopherson --- arch/x86/kernel/cpu/sgx/main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c index 4465912174fd..e455ec7b3449 100644 --- a/arch/x86/kernel/cpu/sgx/main.c +++ b/arch/x86/kernel/cpu/sgx/main.c @@ -48,6 +48,7 @@ static void sgx_sanitize_section(struct sgx_epc_section *section) if (!ret) { spin_lock(§ion->lock); list_move(&page->list, §ion->page_list); + section->free_cnt++; spin_unlock(§ion->lock); } else list_move_tail(&page->list, &dirty); @@ -643,7 +644,6 @@ static bool __init sgx_setup_epc_section(u64 phys_addr, u64 size, list_add_tail(§ion->pages[i].list, §ion->init_laundry_list); } - section->free_cnt = nr_pages; return true; }