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=-16.7 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=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 68740C433EF for ; Fri, 17 Sep 2021 21:39:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 533C161164 for ; Fri, 17 Sep 2021 21:39:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344614AbhIQVkW (ORCPT ); Fri, 17 Sep 2021 17:40:22 -0400 Received: from mga07.intel.com ([134.134.136.100]:54587 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241949AbhIQVkN (ORCPT ); Fri, 17 Sep 2021 17:40:13 -0400 X-IronPort-AV: E=McAfee;i="6200,9189,10110"; a="286563050" X-IronPort-AV: E=Sophos;i="5.85,302,1624345200"; d="scan'208";a="286563050" Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Sep 2021 14:38:50 -0700 X-IronPort-AV: E=Sophos;i="5.85,302,1624345200"; d="scan'208";a="546646804" 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; 17 Sep 2021 14:38:49 -0700 From: Tony Luck To: Sean Christopherson , Jarkko Sakkinen , Dave Hansen Cc: Cathy Zhang , linux-sgx@vger.kernel.org, x86@kernel.org, linux-kernel@vger.kernel.org, Tony Luck Subject: [PATCH v5 3/7] x86/sgx: Initial poison handling for dirty and free pages Date: Fri, 17 Sep 2021 14:38:32 -0700 Message-Id: <20210917213836.175138-4-tony.luck@intel.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210917213836.175138-1-tony.luck@intel.com> References: <20210827195543.1667168-1-tony.luck@intel.com> <20210917213836.175138-1-tony.luck@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org A memory controller patrol scrubber can report poison in a page that isn't currently being used. Add "poison" field in the sgx_epc_page that can be set for an sgx_epc_page. Check for it: 1) When sanitizing dirty pages 2) When freeing epc pages Poison is a new field separated from flags to avoid having to make all updates to flags atomic, or integrate poison state changes into some other locking scheme to protect flags. In both cases place the poisoned page on a list of poisoned epc pages to make sure it will not be reallocated. Add debugfs files /sys/kernel/debug/sgx/poison_page_list so that system administrators get a list of those pages that have been dropped because of poison. Signed-off-by: Tony Luck --- arch/x86/kernel/cpu/sgx/main.c | 30 +++++++++++++++++++++++++++++- arch/x86/kernel/cpu/sgx/sgx.h | 3 ++- 2 files changed, 31 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c index 10892513212d..7a53ff876059 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 @@ -43,6 +44,7 @@ static nodemask_t sgx_numa_mask; static struct sgx_numa_node *sgx_numa_nodes; static LIST_HEAD(sgx_dirty_page_list); +static LIST_HEAD(sgx_poison_page_list); /* * Reset post-kexec EPC pages to the uninitialized state. The pages are removed @@ -62,6 +64,12 @@ static void __sgx_sanitize_pages(struct list_head *dirty_page_list) page = list_first_entry(dirty_page_list, struct sgx_epc_page, list); + if (page->poison) { + list_del(&page->list); + list_add(&page->list, &sgx_poison_page_list); + continue; + } + ret = __eremove(sgx_get_epc_virt_addr(page)); if (!ret) { /* @@ -626,7 +634,10 @@ void sgx_free_epc_page(struct sgx_epc_page *page) spin_lock(&node->lock); page->private = NULL; - list_add_tail(&page->list, &node->free_page_list); + if (page->poison) + list_add(&page->list, &sgx_poison_page_list); + else + list_add_tail(&page->list, &node->free_page_list); sgx_nr_free_pages++; spin_unlock(&node->lock); @@ -657,6 +668,7 @@ 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].poison = 0; section->pages[i].private = "dirty"; list_add_tail(§ion->pages[i].list, &sgx_dirty_page_list); } @@ -801,8 +813,21 @@ int sgx_set_attribute(unsigned long *allowed_attributes, } EXPORT_SYMBOL_GPL(sgx_set_attribute); +static int poison_list_show(struct seq_file *m, void *private) +{ + struct sgx_epc_page *page; + + list_for_each_entry(page, &sgx_poison_page_list, list) + seq_printf(m, "0x%lx\n", sgx_get_epc_phys_addr(page)); + + return 0; +} + +DEFINE_SHOW_ATTRIBUTE(poison_list); + static int __init sgx_init(void) { + struct dentry *dir; int ret; int i; @@ -834,6 +859,9 @@ static int __init sgx_init(void) if (sgx_vepc_init() && ret) goto err_provision; + dir = debugfs_create_dir("sgx", arch_debugfs_dir); + debugfs_create_file("poison_page_list", 0400, dir, NULL, &poison_list_fops); + return 0; err_provision: diff --git a/arch/x86/kernel/cpu/sgx/sgx.h b/arch/x86/kernel/cpu/sgx/sgx.h index 6a55b1971956..77f3d98c9fbf 100644 --- a/arch/x86/kernel/cpu/sgx/sgx.h +++ b/arch/x86/kernel/cpu/sgx/sgx.h @@ -28,7 +28,8 @@ struct sgx_epc_page { unsigned int section; - int flags; + u16 flags; + u16 poison; union { void *private; struct sgx_encl_page *owner; -- 2.31.1