From patchwork Fri Nov 11 18:35:20 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kristen Carlson Accardi X-Patchwork-Id: 13040706 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 75527C43217 for ; Fri, 11 Nov 2022 18:36:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234415AbiKKSgg (ORCPT ); Fri, 11 Nov 2022 13:36:36 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37222 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234118AbiKKSgJ (ORCPT ); Fri, 11 Nov 2022 13:36:09 -0500 Received: from mga17.intel.com (mga17.intel.com [192.55.52.151]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AE0288290B; Fri, 11 Nov 2022 10:36:08 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1668191768; x=1699727768; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=7ztjZ1lXO5N5qsaAMVTmsTfaoQ2t8XkFBGpOnZicwNo=; b=TgBBh/kYsih/e5ziEBSsW36bz0DDQDcAFsqjK0TGP3RghTwJ6R6QdhEG k307Vgma/TIbuq3XAAiJgyR7fP2javZPI/aQR0lNWyPt56Mgj5XdfsYu+ ojUrPBfhAjOo0lN6UxqswD1bXMSx/PuBhTbc5P3hnxYYISSCIIlvttapY o0y9av1Mckr1xoVKnJ3bUW+E/jyurI67UFdLYNGfwyb7qAFFKOOmbqcBf boaWNJmuuY2hVzr+E2xq1wNj7toco6j3HlxfM9Ut7Y+O8S+ZbuJOtlTHr pOpAWbkZ6Yj1EXKcMv89MPDgpgt63aHQona80SmpICKrAF0Oc9MrfVsFj A==; X-IronPort-AV: E=McAfee;i="6500,9779,10528"; a="292050373" X-IronPort-AV: E=Sophos;i="5.96,157,1665471600"; d="scan'208";a="292050373" Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Nov 2022 10:36:08 -0800 X-IronPort-AV: E=McAfee;i="6500,9779,10528"; a="640089313" X-IronPort-AV: E=Sophos;i="5.96,157,1665471600"; d="scan'208";a="640089313" Received: from hermesli-mobl.amr.corp.intel.com (HELO kcaccard-desk.amr.corp.intel.com) ([10.212.218.5]) by fmsmga007-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Nov 2022 10:36:07 -0800 From: Kristen Carlson Accardi To: jarkko@kernel.org, dave.hansen@linux.kernel.org, tj@kernel.org, linux-kernel@vger.kernel.org, linux-sgx@vger.kernel.org, cgroups@vger.kernel.org, Dave Hansen , Thomas Gleixner , Ingo Molnar , Borislav Petkov , x86@kernel.org, "H. Peter Anvin" Cc: zhiquan1.li@intel.com, Kristen Carlson Accardi , Sean Christopherson Subject: [PATCH 15/26] x86/sgx: Add helper to grab pages from an arbitrary EPC LRU Date: Fri, 11 Nov 2022 10:35:20 -0800 Message-Id: <20221111183532.3676646-16-kristen@linux.intel.com> X-Mailer: git-send-email 2.37.3 In-Reply-To: <20221111183532.3676646-1-kristen@linux.intel.com> References: <20221111183532.3676646-1-kristen@linux.intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org From: Sean Christopherson Move the isolation loop into a standalone helper, sgx_isolate_pages(), in preparation for existence of multiple LRUs. Expose the helper to other SGX code so that it can be called from the EPC cgroup code, e.g. to isolate pages from a single cgroup LRU. Exposing the isolation loop allows the cgroup iteration logic to be wholly encapsulated within the cgroup code. Signed-off-by: Sean Christopherson Signed-off-by: Kristen Carlson Accardi Cc: Sean Christopherson --- arch/x86/kernel/cpu/sgx/main.c | 68 +++++++++++++++++++++------------- arch/x86/kernel/cpu/sgx/sgx.h | 2 + 2 files changed, 44 insertions(+), 26 deletions(-) diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c index cb6f57caf24c..f8f1451b0a11 100644 --- a/arch/x86/kernel/cpu/sgx/main.c +++ b/arch/x86/kernel/cpu/sgx/main.c @@ -280,7 +280,46 @@ static void sgx_reclaimer_write(struct sgx_epc_page *epc_page, } /** - * sgx_reclaim_pages() - Reclaim EPC pages from the consumers + * sgx_isolate_epc_pages() - Isolate pages from an LRU for reclaim + * @lru: LRU from which to reclaim + * @nr_to_scan: Number of pages to scan for reclaim + * @dst: Destination list to hold the isolated pages + */ +void sgx_isolate_epc_pages(struct sgx_epc_lru *lru, int *nr_to_scan, + struct list_head *dst) +{ + struct sgx_encl_page *encl_page; + struct sgx_epc_page *epc_page; + + spin_lock(&lru->lock); + for (; *nr_to_scan > 0; --(*nr_to_scan)) { + if (list_empty(&lru->reclaimable)) + break; + + epc_page = sgx_epc_peek_reclaimable(lru); + if (!epc_page) + break; + + encl_page = epc_page->encl_owner; + + if (WARN_ON_ONCE(!(epc_page->flags & SGX_EPC_PAGE_ENCLAVE))) + continue; + + if (kref_get_unless_zero(&encl_page->encl->refcount)) { + epc_page->flags |= SGX_EPC_PAGE_RECLAIM_IN_PROGRESS; + list_move_tail(&epc_page->list, dst); + } else { + /* The owner is freeing the page, remove it from the + * LRU list + */ + epc_page->flags &= ~SGX_EPC_PAGE_RECLAIMER_TRACKED; + list_del_init(&epc_page->list); + } + } + spin_unlock(&lru->lock); +} + +/** * sgx_reclaim_epc_pages() - Reclaim EPC pages from the consumers * @nr_to_scan: Number of EPC pages to scan for reclaim * @ignore_age: Reclaim a page even if it is young @@ -305,37 +344,14 @@ static int __sgx_reclaim_pages(int nr_to_scan, bool ignore_age) struct sgx_epc_lru *lru; pgoff_t page_index; LIST_HEAD(iso); + int i = 0; int ret; - int i; - - spin_lock(&sgx_global_lru.lock); - for (i = 0; i < nr_to_scan; i++) { - epc_page = sgx_epc_peek_reclaimable(&sgx_global_lru); - if (!epc_page) - break; - - encl_page = epc_page->encl_owner; - if (WARN_ON_ONCE(!(epc_page->flags & SGX_EPC_PAGE_ENCLAVE))) - continue; - - if (kref_get_unless_zero(&encl_page->encl->refcount) != 0) { - epc_page->flags |= SGX_EPC_PAGE_RECLAIM_IN_PROGRESS; - list_move_tail(&epc_page->list, &iso); - } else { - /* The owner is freeing the page, remove it from the - * LRU list - */ - epc_page->flags &= ~SGX_EPC_PAGE_RECLAIMER_TRACKED; - list_del_init(&epc_page->list); - } - } - spin_unlock(&sgx_global_lru.lock); + sgx_isolate_epc_pages(&sgx_global_lru, &nr_to_scan, &iso); if (list_empty(&iso)) return 0; - i = 0; list_for_each_entry_safe(epc_page, tmp, &iso, list) { encl_page = epc_page->encl_owner; diff --git a/arch/x86/kernel/cpu/sgx/sgx.h b/arch/x86/kernel/cpu/sgx/sgx.h index ca51b3c7d905..29c37f20792c 100644 --- a/arch/x86/kernel/cpu/sgx/sgx.h +++ b/arch/x86/kernel/cpu/sgx/sgx.h @@ -182,6 +182,8 @@ void sgx_record_epc_page(struct sgx_epc_page *page, unsigned long flags); int sgx_drop_epc_page(struct sgx_epc_page *page); struct sgx_epc_page *sgx_alloc_epc_page(void *owner, bool reclaim); int sgx_reclaim_epc_pages(int nr_to_scan, bool ignore_age); +void sgx_isolate_epc_pages(struct sgx_epc_lru *lru, int *nr_to_scan, + struct list_head *dst); void sgx_ipi_cb(void *info);