From nobody Fri Oct 31 23:10:54 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) client-ip=192.237.175.120; envelope-from=xen-devel-bounces@lists.xenproject.org; helo=lists.xenproject.org; Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; dmarc=fail(p=none dis=none) header.from=arm.com Return-Path: Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) by mx.zohomail.com with SMTPS id 1745940096805373.21865199017293; Tue, 29 Apr 2025 08:21:36 -0700 (PDT) Received: from list by lists.xenproject.org with outflank-mailman.972774.1361097 (Exim 4.92) (envelope-from ) id 1u9mln-0002XA-GR; Tue, 29 Apr 2025 15:21:15 +0000 Received: by outflank-mailman (output) from mailman id 972774.1361097; Tue, 29 Apr 2025 15:21:15 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1u9mln-0002Vt-Aj; Tue, 29 Apr 2025 15:21:15 +0000 Received: by outflank-mailman (input) for mailman id 972774; Tue, 29 Apr 2025 15:21:13 +0000 Received: from se1-gles-flk1-in.inumbo.com ([94.247.172.50] helo=se1-gles-flk1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1u9mll-0002Ky-RN for xen-devel@lists.xenproject.org; Tue, 29 Apr 2025 15:21:13 +0000 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by se1-gles-flk1.inumbo.com (Halon) with ESMTP id 92c143b9-250d-11f0-9ffb-bf95429c2676; Tue, 29 Apr 2025 17:21:08 +0200 (CEST) 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 5ABD81516; Tue, 29 Apr 2025 08:21:00 -0700 (PDT) Received: from e125770.cambridge.arm.com (e125770.arm.com [10.1.199.43]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 3E2133F673; Tue, 29 Apr 2025 08:21:06 -0700 (PDT) X-Outflank-Mailman: Message body and most headers restored to incoming version X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 92c143b9-250d-11f0-9ffb-bf95429c2676 From: Luca Fancellu To: xen-devel@lists.xenproject.org Cc: Stefano Stabellini , Julien Grall , Bertrand Marquis , Michal Orzel , Volodymyr Babchuk Subject: [PATCH v4 1/7] docs/arm: Document Xen booting protocol on Armv8-R Date: Tue, 29 Apr 2025 16:20:51 +0100 Message-Id: <20250429152057.2380536-2-luca.fancellu@arm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20250429152057.2380536-1-luca.fancellu@arm.com> References: <20250429152057.2380536-1-luca.fancellu@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-ZM-MESSAGEID: 1745940096999019000 Content-Type: text/plain; charset="utf-8" Document the requirement needed to boot Xen on Armv8-R platforms. Signed-off-by: Luca Fancellu Reviewed-by: Ayan Kumar Halder Reviewed-by: Michal Orzel --- v4 changes: - New patch --- docs/misc/arm/booting.txt | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/docs/misc/arm/booting.txt b/docs/misc/arm/booting.txt index 21ae74837dcc..719af74f1e69 100644 --- a/docs/misc/arm/booting.txt +++ b/docs/misc/arm/booting.txt @@ -62,6 +62,14 @@ Xen relies on some settings the firmware has to configur= e in EL3 before starting =20 * The bit SCR_EL3.HCE (resp. SCR.HCE for 32-bit ARM) must be set to 1. =20 +When Xen runs on Armv8-R, the highest exception level is EL2 and the only +available state is secure (S) on Arm64 and non secure (NS) on Arm32, hence= the +above requirements need to be adjusted to this case: + +* Xen must be entered in S EL2 mode on Arm64 and in NS EL2 mode on Arm32. + +* Xen must be entered with MPU off and data cache disabled (SCTLR_EL2.M bi= t and + SCTLR_EL2.C set to 0). =20 [1] linux/Documentation/arm/booting.rst Latest version: http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux= .git/tree/Documentation/arch/arm/booting.rst --=20 2.34.1