From patchwork Tue Sep 17 16:02:02 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Julien Grall X-Patchwork-Id: 173895 Delivered-To: patch@linaro.org Received: by 2002:a92:7e96:0:0:0:0:0 with SMTP id q22csp1318318ill; Tue, 17 Sep 2019 09:03:52 -0700 (PDT) X-Google-Smtp-Source: APXvYqwbixA0QOV6pUiN+iHJbzzMzQE5x5YqDcugQFUsTKpNMF7e0vgjG0YBqtv11SQdRo9CTah3 X-Received: by 2002:a9d:5a0d:: with SMTP id v13mr3253252oth.13.1568736232497; Tue, 17 Sep 2019 09:03:52 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1568736232; cv=none; d=google.com; s=arc-20160816; b=PctcAVqqbRYWXAOT7c7PNQh0l6ENrKkJITgvaUnkC6+9F7YqZX66i00sgmCx+pnbt6 0RnYN0W5Fi5679qyR5LOEkKGHfe5R9e8jtNac+5JD/AyLKDLlvMsaAUaLhWjo54Wj6Uz zHEQY//9mAAbsYVqUgH8BzhLJLvn2ezjmyVqrYk2XzAx30aOWX+47oDSeFqrPwIrV03R I/5Ubv6LUpwFh6ZmlOm5uDZHGyfEbRkwjwkgYMY4Ny8XXwvshiRm5oBs4FkdA+lYtA7m DZv/zx3pzz2uPIdQ3Ut9uS+Z1837473lsEENVUHAEiXfLQmeh0QYvwMQ/bAiq40Okj+H aLiw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=sender:errors-to:content-transfer-encoding:mime-version:cc :list-subscribe:list-help:list-post:list-unsubscribe:list-id :precedence:subject:message-id:date:to:from; bh=f/JQLQLFZQuBBtrZ5Cve3YTLb/HihGL3CycN+Snq3So=; b=Ys/bODZDdZwYVybnaOqVx1tg2AVt/Zcl5v1jk4QMff4bydLRWumsFgCVI3GDfySR/g WS869x/XrsruBPb/WyPD6mCPplIfT8IAFC98cEBmnFzB8IAL0r2XoRzbCZktjhcVTZ6U 2AfTMf/ef/d3Ka41Q87c6LKFjJXIPfsEZCbybmQqiHx+iu+DABUpGnXgOhvOk/2dIet0 /frgIj0K9TB34+3H6fF4kz72MUiIRtc142YpdP0BC9vEoxJrnx6819jg6BVu1/uARiD9 XI8udYJZ5ndv3+813kCY2pMVsdlcFlevPSK3LH44bUUc3AidVBRpdUN0ppMAwCICHKAh Tjxg== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of xen-devel-bounces@lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Return-Path: Received: from lists.xenproject.org (lists.xenproject.org. [192.237.175.120]) by mx.google.com with ESMTPS id l65si1077430otl.76.2019.09.17.09.03.52 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Tue, 17 Sep 2019 09:03:52 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of xen-devel-bounces@lists.xenproject.org designates 192.237.175.120 as permitted sender) client-ip=192.237.175.120; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of xen-devel-bounces@lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1iAFve-00081N-UF; Tue, 17 Sep 2019 16:02:10 +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 1iAFvc-00081I-OX for xen-devel@lists.xenproject.org; Tue, 17 Sep 2019 16:02:08 +0000 X-Inumbo-ID: 7fa0af48-d964-11e9-9619-12813bfff9fa Received: from foss.arm.com (unknown [217.140.110.172]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTP id 7fa0af48-d964-11e9-9619-12813bfff9fa; Tue, 17 Sep 2019 16:02:07 +0000 (UTC) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 1142815A2; Tue, 17 Sep 2019 09:02:07 -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 5E3273F575; Tue, 17 Sep 2019 09:02:06 -0700 (PDT) From: Julien Grall To: xen-devel@lists.xenproject.org Date: Tue, 17 Sep 2019 17:02:02 +0100 Message-Id: <20190917160202.16770-1-julien.grall@arm.com> X-Mailer: git-send-email 2.11.0 Subject: [Xen-devel] [[PATCH for-4.13]] xen/arm: mm: Allow generic xen page-tables helpers to be called early 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: Julien Grall , Stefano Stabellini , Volodymyr Babchuk MIME-Version: 1.0 Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" The current implementations of xen_{map, unmap}_table() expect {map, unmap}_domain_page() to be usable. Those helpers are used to map/unmap page tables while update Xen page-tables. Since commit 022387ee1a "xen/arm: mm: Don't open-code Xen PT update in {set, clear}_fixmap()", setup_fixmap() will make use of the helpers mentioned above. When booting Xen using GRUB, setup_fixmap() may be used before map_domain_page() can be called. This will result to data abort: (XEN) Data Abort Trap. Syndrome=0x5 (XEN) CPU0: Unexpected Trap: Data Abort [...] (XEN) Xen call trace: (XEN) [<000000000025ab6c>] mm.c#xen_pt_update+0x2b4/0x59c (PC) (XEN) [<000000000025ab20>] mm.c#xen_pt_update+0x268/0x59c (LR) (XEN) [<000000000025ae70>] set_fixmap+0x1c/0x2c (XEN) [<00000000002a9c98>] copy_from_paddr+0x7c/0xdc (XEN) [<00000000002a4ae0>] has_xsm_magic+0x18/0x34 (XEN) [<00000000002a5b5c>] bootfdt.c#early_scan_node+0x398/0x560 (XEN) [<00000000002a5de0>] device_tree_for_each_node+0xbc/0x144 (XEN) [<00000000002a5ed4>] boot_fdt_info+0x6c/0x260 (XEN) [<00000000002ac0d0>] start_xen+0x108/0xc74 (XEN) [<000000000020044c>] arm64/head.o#paging+0x60/0x88 During early boot, the page tables are either statically allocated in Xen binary or allocated via alloc_boot_pages(). For statically allocated page-tables, they will already be mapped as part of Xen binary. So we can easily find the virtual address. For dynamically allocated page-tables, we need to rely map_domain_page() to be functionally working. For arm32, the call will be usable much before page can be dynamically allocated (see setup_pagetables()). For arm64, the call will be usable after setup_xenheap_mappings(). In both cases, memory are given to the boot allocator afterwards. So we can rely on map_domain_page() for mapping page tables allocated dynamically. The helpers xen_{map, unmap}_table() are now updated to take into account the case where page-tables are part of Xen binary. Fixes: 022387ee1a ('xen/arm: mm: Don't open-code Xen PT update in {set, clear}_fixmap()') Signed-off-by: Julien Grall --- xen/arch/arm/mm.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/xen/arch/arm/mm.c b/xen/arch/arm/mm.c index e1cdeaaf2f..da6303a8fd 100644 --- a/xen/arch/arm/mm.c +++ b/xen/arch/arm/mm.c @@ -950,11 +950,31 @@ static int create_xen_table(lpae_t *entry) static lpae_t *xen_map_table(mfn_t mfn) { + /* + * We may require to map the page table before map_domain_page() is + * useable. The requirements here is it must be useable as soon as + * page-tables are allocated dynamically via alloc_boot_pages(). + */ + if ( system_state == SYS_STATE_early_boot ) + { + vaddr_t va = mfn_to_maddr(mfn) - phys_offset; + + if ( is_kernel(va) ) + return (lpae_t *)va; + } + return map_domain_page(mfn); } static void xen_unmap_table(const lpae_t *table) { + /* + * During early boot, xen_map_table() will not use map_domain_page() + * for page-tables residing in Xen binary. So skip the unmap part. + */ + if ( system_state == SYS_STATE_early_boot && is_kernel(table) ) + return; + unmap_domain_page(table); }