From patchwork Thu Aug 31 15:55:08 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jan Beulich X-Patchwork-Id: 9932489 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 21444602F0 for ; Thu, 31 Aug 2017 15:57:19 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 15BA5289E6 for ; Thu, 31 Aug 2017 15:57:19 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 0A524289EB; Thu, 31 Aug 2017 15:57:19 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 7BBDA289E6 for ; Thu, 31 Aug 2017 15:57:18 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.84_2) (envelope-from ) id 1dnRoH-0003UT-Rk; Thu, 31 Aug 2017 15:55:13 +0000 Received: from mail6.bemta6.messagelabs.com ([193.109.254.103]) by lists.xenproject.org with esmtp (Exim 4.84_2) (envelope-from ) id 1dnRoH-0003UG-00 for xen-devel@lists.xenproject.org; Thu, 31 Aug 2017 15:55:13 +0000 Received: from [85.158.143.35] by server-5.bemta-6.messagelabs.com id 98/0A-03454-06138A95; Thu, 31 Aug 2017 15:55:12 +0000 X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFprOIsWRWlGSWpSXmKPExsXS6fjDSzfecEW kwaytBhbft0xmcmD0OPzhCksAYxRrZl5SfkUCa8aclbvZC3byVcy42MXWwHibq4uRk0NIIE9i 4tFWVhCbV8BOYvrOFewgtoSAocTphTdZQGwWAVWJb0f3MoLYbALqEm3PtgPVc3CICBhInDuaB GIyC+hLbFsHVi0sYCRx5NMPRojpdhJPfi0Gq+YVEJT4u0MYJMwsoCXx8NctFghbW2LZwtfMEF OkJZb/45jAyDsLoWEWkoZZSBpmITQsYGRZxahRnFpUllqka2ykl1SUmZ5RkpuYmaNraGCml5t aXJyYnpqTmFSsl5yfu4kRGGAMQLCD8fS6wEOMkhxMSqK8D28vjxTiS8pPqcxILM6ILyrNSS0+ xCjDwaEkwbtAf0WkkGBRanpqRVpmDjDUYdISHDxKIry+IGne4oLE3OLMdIjUKUZFKXFedwOgh ABIIqM0D64NFl+XGGWlhHkZgQ4R4ilILcrNLEGVf8UozsGoJMx7BWQ8T2ZeCdz0V0CLmYAWx3 otBVlckoiQkmpgNOqepyLLK7B7Z51ihuvipde8XiiZNR0/p7RxT9nq9o3TVf0PMJlM3c+ru94 t5GDCO6WXr8SEY2be+V90htNk0in7s9veVpk0/uOx8Ntp3XE1f+LJeerR7n213fyfEw5uuXs/ +fbfN/O21V7pOqJ+9Xby2z2R9o1/F8hviwjMehuW8uublm1uphJLcUaioRZzUXEiAKacer6qA gAA X-Env-Sender: JBeulich@suse.com X-Msg-Ref: server-10.tower-21.messagelabs.com!1504194910!73884840!1 X-Originating-IP: [137.65.248.74] X-SpamReason: No, hits=0.0 required=7.0 tests= X-StarScan-Received: X-StarScan-Version: 9.4.45; banners=-,-,- X-VirusChecked: Checked Received: (qmail 25889 invoked from network); 31 Aug 2017 15:55:11 -0000 Received: from prv-mh.provo.novell.com (HELO prv-mh.provo.novell.com) (137.65.248.74) by server-10.tower-21.messagelabs.com with DHE-RSA-AES256-GCM-SHA384 encrypted SMTP; 31 Aug 2017 15:55:11 -0000 Received: from INET-PRV-MTA by prv-mh.provo.novell.com with Novell_GroupWise; Thu, 31 Aug 2017 09:55:09 -0600 Message-Id: <59A84D7C02000078001763F0@prv-mh.provo.novell.com> X-Mailer: Novell GroupWise Internet Agent 14.2.2 Date: Thu, 31 Aug 2017 09:55:08 -0600 From: "Jan Beulich" To: "xen-devel" References: <59A84D7C02000078001763F0@prv-mh.provo.novell.com> Mime-Version: 1.0 Content-Disposition: inline Cc: Andrew Cooper Subject: [Xen-devel] [PATCH] x86: mark the entire directmap NX X-BeenThere: xen-devel@lists.xen.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xen.org Sender: "Xen-devel" X-Virus-Scanned: ClamAV using ClamSMTP There's no reason for the first Mb to be excluded here. Enforce the restriction right in the top level page table entries. Suggested-by: Andrew Cooper Signed-off-by: Jan Beulich Reviewed-by: Andrew Cooper --- a/xen/arch/x86/x86_64/mm.c +++ b/xen/arch/x86/x86_64/mm.c @@ -887,32 +887,21 @@ void __init subarch_init_memory(void) } } - /* Mark low 16Mb of direct map NX if hardware supports it. */ + /* Mark all of direct map NX if hardware supports it. */ if ( !cpu_has_nx ) return; - v = DIRECTMAP_VIRT_START + (1UL << 20); - l3e = l4e_to_l3e(idle_pg_table[l4_table_offset(v)])[l3_table_offset(v)]; - ASSERT(l3e_get_flags(l3e) & _PAGE_PRESENT); - do { - l2e = l3e_to_l2e(l3e)[l2_table_offset(v)]; - ASSERT(l2e_get_flags(l2e) & _PAGE_PRESENT); - if ( l2e_get_flags(l2e) & _PAGE_PSE ) - { - l2e_add_flags(l2e, _PAGE_NX_BIT); - l3e_to_l2e(l3e)[l2_table_offset(v)] = l2e; - v += 1 << L2_PAGETABLE_SHIFT; - } - else - { - l1_pgentry_t l1e = l2e_to_l1e(l2e)[l1_table_offset(v)]; + for ( i = l4_table_offset(DIRECTMAP_VIRT_START); + i < l4_table_offset(DIRECTMAP_VIRT_END); ++i ) + { + l4_pgentry_t l4e = idle_pg_table[i]; - ASSERT(l1e_get_flags(l1e) & _PAGE_PRESENT); - l1e_add_flags(l1e, _PAGE_NX_BIT); - l2e_to_l1e(l2e)[l1_table_offset(v)] = l1e; - v += 1 << L1_PAGETABLE_SHIFT; + if ( l4e_get_flags(l4e) & _PAGE_PRESENT ) + { + l4e_add_flags(l4e, _PAGE_NX_BIT); + idle_pg_table[i] = l4e; } - } while ( v < DIRECTMAP_VIRT_START + (16UL << 20) ); + } } long subarch_memory_op(unsigned long cmd, XEN_GUEST_HANDLE_PARAM(void) arg)