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=-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,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 39397C4338F for ; Wed, 28 Jul 2021 20:47:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1A142610A1 for ; Wed, 28 Jul 2021 20:47:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231852AbhG1UrS (ORCPT ); Wed, 28 Jul 2021 16:47:18 -0400 Received: from mga01.intel.com ([192.55.52.88]:60188 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231633AbhG1UrE (ORCPT ); Wed, 28 Jul 2021 16:47:04 -0400 X-IronPort-AV: E=McAfee;i="6200,9189,10059"; a="234634459" X-IronPort-AV: E=Sophos;i="5.84,276,1620716400"; d="scan'208";a="234634459" Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Jul 2021 13:47:01 -0700 X-IronPort-AV: E=Sophos;i="5.84,276,1620716400"; d="scan'208";a="506679872" Received: from agluck-desk2.sc.intel.com ([10.3.52.146]) by fmsmga003-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Jul 2021 13:47:01 -0700 From: Tony Luck To: Sean Christopherson , Jarkko Sakkinen , Dave Hansen Cc: x86@kernel.org, linux-kernel@vger.kernel.org, Tony Luck Subject: [PATCH v3 1/7] x86/sgx: Provide indication of life-cycle of EPC pages Date: Wed, 28 Jul 2021 13:46:47 -0700 Message-Id: <20210728204653.1509010-2-tony.luck@intel.com> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210728204653.1509010-1-tony.luck@intel.com> References: <20210719182009.1409895-1-tony.luck@intel.com> <20210728204653.1509010-1-tony.luck@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org SGX EPC pages go through the following life cycle: DIRTY ---> FREE ---> IN-USE --\ ^ | \-----------------/ Recovery action for poison for a DIRTY or FREE page is simple. Just make sure never to allocate the page. IN-USE pages need some extra handling. It would be good to use the sgx_epc_page->owner field as an indicator of where an EPC page is currently in that cycle (owner != NULL means the EPC page is IN-USE). But there is one caller, sgx_alloc_va_page(), that calls with NULL. Make the following changes: 1) Change the type of "owner" to "void *" (it can have other types besides "struct sgx_encl_page *). 2) Add a check to sgx_free_epc_page(). If the caller specified the owner as NULL, then set the owner field to self-reference the SGX epc page itself. 3) Reset owner to NULL in sgx_free_epc_page(). Signed-off-by: Tony Luck --- arch/x86/kernel/cpu/sgx/main.c | 3 ++- arch/x86/kernel/cpu/sgx/sgx.h | 2 +- 2 files changed, 3 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c index 63d3de02bbcc..17d09186a6c2 100644 --- a/arch/x86/kernel/cpu/sgx/main.c +++ b/arch/x86/kernel/cpu/sgx/main.c @@ -581,7 +581,7 @@ struct sgx_epc_page *sgx_alloc_epc_page(void *owner, bool reclaim) for ( ; ; ) { page = __sgx_alloc_epc_page(); if (!IS_ERR(page)) { - page->owner = owner; + page->owner = owner ? owner : page; break; } @@ -624,6 +624,7 @@ void sgx_free_epc_page(struct sgx_epc_page *page) spin_lock(&node->lock); + page->owner = NULL; list_add_tail(&page->list, &node->free_page_list); sgx_nr_free_pages++; diff --git a/arch/x86/kernel/cpu/sgx/sgx.h b/arch/x86/kernel/cpu/sgx/sgx.h index 4628acec0009..4e1a410b8a62 100644 --- a/arch/x86/kernel/cpu/sgx/sgx.h +++ b/arch/x86/kernel/cpu/sgx/sgx.h @@ -29,7 +29,7 @@ struct sgx_epc_page { unsigned int section; unsigned int flags; - struct sgx_encl_page *owner; + void *owner; struct list_head list; }; -- 2.29.2