From patchwork Mon Oct 18 20:25:36 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tony Luck X-Patchwork-Id: 12567989 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 0971DC4167D for ; Mon, 18 Oct 2021 20:25:55 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 888D8610A1 for ; Mon, 18 Oct 2021 20:25:54 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 888D8610A1 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id 86667900005; Mon, 18 Oct 2021 16:25:53 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 84E0B900006; Mon, 18 Oct 2021 16:25:53 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 6C773900005; Mon, 18 Oct 2021 16:25:53 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0077.hostedemail.com [216.40.44.77]) by kanga.kvack.org (Postfix) with ESMTP id 5E9EC900003 for ; Mon, 18 Oct 2021 16:25:53 -0400 (EDT) Received: from smtpin26.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 19E6E1802C53E for ; Mon, 18 Oct 2021 20:25:53 +0000 (UTC) X-FDA: 78710689386.26.82CCAD8 Received: from mga03.intel.com (mga03.intel.com [134.134.136.65]) by imf13.hostedemail.com (Postfix) with ESMTP id BAB2F10467F5 for ; Mon, 18 Oct 2021 20:25:49 +0000 (UTC) X-IronPort-AV: E=McAfee;i="6200,9189,10141"; a="228307008" X-IronPort-AV: E=Sophos;i="5.85,382,1624345200"; d="scan'208";a="228307008" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Oct 2021 13:25:50 -0700 X-IronPort-AV: E=Sophos;i="5.85,382,1624345200"; d="scan'208";a="493758167" 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; 18 Oct 2021 13:25:49 -0700 From: Tony Luck To: "Rafael J. Wysocki" , naoya.horiguchi@nec.com Cc: Andrew Morton , Sean Christopherson , Jarkko Sakkinen , Dave Hansen , Cathy Zhang , linux-sgx@vger.kernel.org, linux-acpi@vger.kernel.org, linux-mm@kvack.org, Tony Luck , Reinette Chatre Subject: [PATCH v10 1/7] x86/sgx: Add new sgx_epc_page flag bit to mark free pages Date: Mon, 18 Oct 2021 13:25:36 -0700 Message-Id: <20211018202542.584115-2-tony.luck@intel.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20211018202542.584115-1-tony.luck@intel.com> References: <20211011185924.374213-1-tony.luck@intel.com> <20211018202542.584115-1-tony.luck@intel.com> MIME-Version: 1.0 X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: BAB2F10467F5 X-Stat-Signature: sdnymog5uunr3knj9qpzdmkbun8r199d Authentication-Results: imf13.hostedemail.com; dkim=none; dmarc=fail reason="No valid SPF, No valid DKIM" header.from=intel.com (policy=none); spf=none (imf13.hostedemail.com: domain of tony.luck@intel.com has no SPF policy when checking 134.134.136.65) smtp.mailfrom=tony.luck@intel.com X-HE-Tag: 1634588749-68119 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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;