From patchwork Tue Oct 26 22:00:44 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tony Luck X-Patchwork-Id: 12585755 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 76826C433EF for ; Tue, 26 Oct 2021 22:01:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5B7AF6109D for ; Tue, 26 Oct 2021 22:01:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239746AbhJZWED (ORCPT ); Tue, 26 Oct 2021 18:04:03 -0400 Received: from mga18.intel.com ([134.134.136.126]:57938 "EHLO mga18.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239729AbhJZWEC (ORCPT ); Tue, 26 Oct 2021 18:04:02 -0400 X-IronPort-AV: E=McAfee;i="6200,9189,10149"; a="216934484" X-IronPort-AV: E=Sophos;i="5.87,184,1631602800"; d="scan'208";a="216934484" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by orsmga106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Oct 2021 15:00:59 -0700 X-IronPort-AV: E=Sophos;i="5.87,184,1631602800"; d="scan'208";a="497555754" Received: from agluck-desk2.sc.intel.com ([10.3.52.146]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Oct 2021 15:00:59 -0700 From: Tony Luck To: Borislav Petkov , x86@kernel.org Cc: "Rafael J. Wysocki" , naoya.horiguchi@nec.com, Andrew Morton , Sean Christopherson , Jarkko Sakkinen , Dave Hansen , Cathy Zhang , linux-sgx@vger.kernel.org, linux-acpi@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Tony Luck , Reinette Chatre Subject: [PATCH v11 1/7] x86/sgx: Add new sgx_epc_page flag bit to mark free pages Date: Tue, 26 Oct 2021 15:00:44 -0700 Message-Id: <20211026220050.697075-2-tony.luck@intel.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20211026220050.697075-1-tony.luck@intel.com> References: <20211018202542.584115-1-tony.luck@intel.com> <20211026220050.697075-1-tony.luck@intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-sgx@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. Add a new flag bit SGX_EPC_PAGE_IS_FREE that is set when a page is added to a free list and cleared when the page is allocated. Notes: 1) These transitions are made while holding the node->lock so that future code that checks the flags while holding the node->lock can be sure that if the SGX_EPC_PAGE_IS_FREE bit is set, then the page is on the free list. 2) Initially while the pages are on the dirty list the SGX_EPC_PAGE_IS_FREE bit is cleared. Reviewed-by: Jarkko Sakkinen Tested-by: Reinette Chatre Signed-off-by: Tony Luck --- arch/x86/kernel/cpu/sgx/main.c | 2 ++ arch/x86/kernel/cpu/sgx/sgx.h | 3 +++ 2 files changed, 5 insertions(+) diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c index 63d3de02bbcc..825aa91516c8 100644 --- a/arch/x86/kernel/cpu/sgx/main.c +++ b/arch/x86/kernel/cpu/sgx/main.c @@ -472,6 +472,7 @@ static struct sgx_epc_page *__sgx_alloc_epc_page_from_node(int nid) page = list_first_entry(&node->free_page_list, struct sgx_epc_page, list); list_del_init(&page->list); sgx_nr_free_pages--; + page->flags = 0; spin_unlock(&node->lock); @@ -626,6 +627,7 @@ void sgx_free_epc_page(struct sgx_epc_page *page) list_add_tail(&page->list, &node->free_page_list); sgx_nr_free_pages++; + page->flags = SGX_EPC_PAGE_IS_FREE; spin_unlock(&node->lock); } diff --git a/arch/x86/kernel/cpu/sgx/sgx.h b/arch/x86/kernel/cpu/sgx/sgx.h index 4628acec0009..5906471156c5 100644 --- a/arch/x86/kernel/cpu/sgx/sgx.h +++ b/arch/x86/kernel/cpu/sgx/sgx.h @@ -26,6 +26,9 @@ /* Pages, which are being tracked by the page reclaimer. */ #define SGX_EPC_PAGE_RECLAIMER_TRACKED BIT(0) +/* Pages on free list */ +#define SGX_EPC_PAGE_IS_FREE BIT(1) + struct sgx_epc_page { unsigned int section; unsigned int flags;