From patchwork Tue May 14 12:31:22 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Julien Grall X-Patchwork-Id: 10942951 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 31A571390 for ; Tue, 14 May 2019 12:32:37 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 218C0286AC for ; Tue, 14 May 2019 12:32:37 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 15D87286F6; Tue, 14 May 2019 12:32:37 +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=-5.2 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, 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 AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id AA004286E0 for ; Tue, 14 May 2019 12:32:36 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1hQWaw-0005Qu-55; Tue, 14 May 2019 12:31:46 +0000 Received: from all-amaz-eas1.inumbo.com ([34.197.232.57] helo=us1-amaz-eas2.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1hQWav-0005Q2-GG for xen-devel@lists.xenproject.org; Tue, 14 May 2019 12:31:45 +0000 X-Inumbo-ID: 3be35306-7644-11e9-9745-a782c9656c67 Received: from foss.arm.com (unknown [217.140.101.70]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTP id 3be35306-7644-11e9-9745-a782c9656c67; Tue, 14 May 2019 12:31:44 +0000 (UTC) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 70476341; Tue, 14 May 2019 05:31:44 -0700 (PDT) Received: from e108454-lin.cambridge.arm.com (e108454-lin.cambridge.arm.com [10.1.196.50]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 3C40F3F71E; Tue, 14 May 2019 05:31:43 -0700 (PDT) From: Julien Grall To: xen-devel@lists.xenproject.org Date: Tue, 14 May 2019 13:31:22 +0100 Message-Id: <20190514123125.29086-10-julien.grall@arm.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20190514123125.29086-1-julien.grall@arm.com> References: <20190514123125.29086-1-julien.grall@arm.com> Subject: [Xen-devel] [PATCH MM-PART3 v2 09/12] xen/arm: mm: Use {, un}map_domain_page() to map/unmap Xen page-tables X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: Oleksandr_Tyshchenko@epam.com, Julien Grall , Stefano Stabellini , Andrii Anisov MIME-Version: 1.0 Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" X-Virus-Scanned: ClamAV using ClamSMTP Currently, the virtual address of the 3rd level page-tables is obtained using mfn_to_virt(). On Arm32, mfn_to_virt can only work on xenheap page. While in practice all the page-tables updated will reside in xenheap, in practive the page-tables covering Xen memory (e.g xen_mapping) is part of Xen binary. Furthermore, a follow-up change will update xen_pt_update_entry() to walk all the levels and therefore be more generic. Some of the page-tables will also part of Xen memory and therefore will not be reachable using mfn_to_virt(). The easiest way to reach those pages is to use {, un}map_domain_page(). While on arm32 this means an extra mapping in the normal cases, this is not very important as xen page-tables are not updated often. In order to allow future change in the way Xen page-tables are mapped, two new helpers are introduced to map/unmap the page-tables. Signed-off-by: Julien Grall Reviewed-by: Andrii Anisov Acked-by: Stefano Stabellini --- Changes in v2: - Add Andrii's reviewed-by --- xen/arch/arm/mm.c | 26 ++++++++++++++++++++++---- 1 file changed, 22 insertions(+), 4 deletions(-) diff --git a/xen/arch/arm/mm.c b/xen/arch/arm/mm.c index 651e296041..f5979f549b 100644 --- a/xen/arch/arm/mm.c +++ b/xen/arch/arm/mm.c @@ -974,6 +974,16 @@ static int create_xen_table(lpae_t *entry) return 0; } +static lpae_t *xen_map_table(mfn_t mfn) +{ + return map_domain_page(mfn); +} + +static void xen_unmap_table(const lpae_t *table) +{ + unmap_domain_page(table); +} + /* Sanity check of the entry */ static bool xen_pt_check_entry(lpae_t entry, mfn_t mfn, unsigned int flags) { @@ -1036,6 +1046,7 @@ static bool xen_pt_check_entry(lpae_t entry, mfn_t mfn, unsigned int flags) static int xen_pt_update_entry(unsigned long addr, mfn_t mfn, unsigned int flags) { + int rc; lpae_t pte, *entry; lpae_t *third = NULL; @@ -1054,15 +1065,17 @@ static int xen_pt_update_entry(unsigned long addr, mfn_t mfn, BUG_ON(!lpae_is_valid(*entry)); - third = mfn_to_virt(lpae_get_mfn(*entry)); + third = xen_map_table(lpae_get_mfn(*entry)); entry = &third[third_table_offset(addr)]; + rc = -EINVAL; if ( !xen_pt_check_entry(*entry, mfn, flags) ) - return -EINVAL; + goto out; /* If we are only populating page-table, then we are done. */ + rc = 0; if ( flags & _PAGE_POPULATE ) - return 0; + goto out; /* We are removing the page */ if ( !(flags & _PAGE_PRESENT) ) @@ -1087,7 +1100,12 @@ static int xen_pt_update_entry(unsigned long addr, mfn_t mfn, write_pte(entry, pte); - return 0; + rc = 0; + +out: + xen_unmap_table(third); + + return rc; } static DEFINE_SPINLOCK(xen_pt_lock);