From patchwork Thu Jul 21 13:21:06 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Penny Zheng X-Patchwork-Id: 12925116 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 lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id C256DCCA487 for ; Thu, 21 Jul 2022 13:21:55 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.372751.604678 (Exim 4.92) (envelope-from ) id 1oEW7W-0001jr-FF; Thu, 21 Jul 2022 13:21:38 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 372751.604678; Thu, 21 Jul 2022 13:21:38 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1oEW7W-0001jk-Cd; Thu, 21 Jul 2022 13:21:38 +0000 Received: by outflank-mailman (input) for mailman id 372751; Thu, 21 Jul 2022 13:21:36 +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 1oEW7U-0001je-KU for xen-devel@lists.xenproject.org; Thu, 21 Jul 2022 13:21:36 +0000 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by se1-gles-flk1.inumbo.com (Halon) with ESMTP id 0a87f646-08f8-11ed-924f-1f966e50362f; Thu, 21 Jul 2022 15:21:34 +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 22F2123A; Thu, 21 Jul 2022 06:21:34 -0700 (PDT) Received: from a011292.shanghai.arm.com (a011292.shanghai.arm.com [10.169.190.94]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 5EF9F3F73D; Thu, 21 Jul 2022 06:21:30 -0700 (PDT) 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: 0a87f646-08f8-11ed-924f-1f966e50362f From: Penny Zheng To: xen-devel@lists.xenproject.org Cc: Penny Zheng , Stefano Stabellini , Julien Grall , Bertrand Marquis , Volodymyr Babchuk , Andrew Cooper , George Dunlap , Jan Beulich , Wei Liu Subject: [PATCH v6 0/9] static shared memory on dom0less system Date: Thu, 21 Jul 2022 21:21:06 +0800 Message-Id: <20220721132115.3015761-1-Penny.Zheng@arm.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 In safety-critical environment, it is not considered safe to dynamically change important configurations at runtime. Everything should be statically defined and statically verified. In this case, if the system configuration knows a priori that there are only 2 VMs and they need to communicate over shared memory, it is safer to pre-configure the shared memory at build time rather than let the VMs attempt to share memory at runtime. And it is faster too. Furthermore, on dom0less system, the legacy way to build up communication channels between domains, like grant table, are normally absent there. So this patch serie introduces a set of static shared memory device tree nodes to allow users to statically set up shared memory on dom0less system, enabling domains to do shm-based communication. The only way to trigger this static shared memory configuration should be via device tree, which is at the same level as the XSM rules. It was inspired by the patch serie of ["xl/libxl-based shared mem]( https://marc.info/?l=xen-devel&m=154404821731186ory"). Looking into related [design link]( https://lore.kernel.org/all/a50d9fde-1d06-7cda-2779-9eea9e1c0134@xen.org/T/) for more details. Penny Zheng (9): xen/arm: introduce static shared memory xen/arm: allocate static shared memory to the default owner dom_io xen/arm: allocate static shared memory to a specific owner domain xen/arm: introduce put_page_nr and get_page_nr xen/arm: Add additional reference to owner domain when the owner is allocated xen/arm: set up shared memory foreign mapping for borrower domain xen/arm: create shared memory nodes in guest device tree xen/arm: enable statically shared memory on Dom0 xen: Add static memory sharing in SUPPORT.md SUPPORT.md | 6 + docs/misc/arm/device-tree/booting.txt | 124 ++++++++ xen/arch/arm/Kconfig | 6 + xen/arch/arm/bootfdt.c | 157 ++++++++++ xen/arch/arm/domain_build.c | 402 ++++++++++++++++++++++++++ xen/arch/arm/include/asm/kernel.h | 1 + xen/arch/arm/include/asm/mm.h | 4 + xen/arch/arm/include/asm/setup.h | 9 + xen/arch/arm/mm.c | 42 ++- xen/common/domain.c | 3 + 10 files changed, 745 insertions(+), 9 deletions(-)