From patchwork Mon Sep 27 21:34:46 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Luck, Tony" X-Patchwork-Id: 12520831 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 6231EC433F5 for ; Mon, 27 Sep 2021 21:35:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 38B156113D for ; Mon, 27 Sep 2021 21:35:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237043AbhI0Vgk (ORCPT ); Mon, 27 Sep 2021 17:36:40 -0400 Received: from mga07.intel.com ([134.134.136.100]:2372 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236743AbhI0Vgj (ORCPT ); Mon, 27 Sep 2021 17:36:39 -0400 X-IronPort-AV: E=McAfee;i="6200,9189,10120"; a="288227510" X-IronPort-AV: E=Sophos;i="5.85,327,1624345200"; d="scan'208";a="288227510" Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Sep 2021 14:35:01 -0700 X-IronPort-AV: E=Sophos;i="5.85,327,1624345200"; d="scan'208";a="561547569" Received: from agluck-desk2.sc.intel.com ([10.3.52.146]) by fmsmga002-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Sep 2021 14:35:00 -0700 From: Tony Luck To: Sean Christopherson , Jarkko Sakkinen , Dave Hansen Cc: Cathy Zhang , linux-sgx@vger.kernel.org, Tony Luck Subject: [PATCH v7 1/7] x86/sgx: Add new sgx_epc_page flag bit to mark in-use pages Date: Mon, 27 Sep 2021 14:34:46 -0700 Message-Id: <20210927213452.212470-2-tony.luck@intel.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210927213452.212470-1-tony.luck@intel.com> References: <20210922182123.200105-1-tony.luck@intel.com> <20210927213452.212470-1-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_IN_USE that is set when a page is allocated and cleared when the page is freed. 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_IN_USE 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_IN_USE bit is set. Signed-off-by: Tony Luck Reviewed-by: Jarkko Sakkinen --- arch/x86/kernel/cpu/sgx/main.c | 4 +++- arch/x86/kernel/cpu/sgx/sgx.h | 3 +++ 2 files changed, 6 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c index 63d3de02bbcc..d18988a46c13 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 = SGX_EPC_PAGE_IN_USE; 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 = 0; spin_unlock(&node->lock); } @@ -651,7 +653,7 @@ static bool __init sgx_setup_epc_section(u64 phys_addr, u64 size, for (i = 0; i < nr_pages; i++) { section->pages[i].section = index; - section->pages[i].flags = 0; + section->pages[i].flags = SGX_EPC_PAGE_IN_USE; section->pages[i].owner = NULL; list_add_tail(§ion->pages[i].list, &sgx_dirty_page_list); } diff --git a/arch/x86/kernel/cpu/sgx/sgx.h b/arch/x86/kernel/cpu/sgx/sgx.h index 4628acec0009..f9202d3d6278 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) +/* Allocated pages */ +#define SGX_EPC_PAGE_IN_USE BIT(1) + struct sgx_epc_page { unsigned int section; unsigned int flags;