From patchwork Fri May 24 12:40:55 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luca Fancellu X-Patchwork-Id: 13673120 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 28E07C41513 for ; Fri, 24 May 2024 12:41:24 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.729486.1134692 (Exim 4.92) (envelope-from ) id 1sAUEX-00015Q-Ks; Fri, 24 May 2024 12:41:17 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 729486.1134692; Fri, 24 May 2024 12:41:17 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1sAUEX-00014Q-8P; Fri, 24 May 2024 12:41:17 +0000 Received: by outflank-mailman (input) for mailman id 729486; Fri, 24 May 2024 12:41:15 +0000 Received: from se1-gles-sth1-in.inumbo.com ([159.253.27.254] helo=se1-gles-sth1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1sAUEV-00082M-CV for xen-devel@lists.xenproject.org; Fri, 24 May 2024 12:41:15 +0000 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by se1-gles-sth1.inumbo.com (Halon) with ESMTP id e7f8bfe5-19ca-11ef-90a1-e314d9c70b13; Fri, 24 May 2024 14:41:14 +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 8970B169C; Fri, 24 May 2024 05:41:37 -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 63B653F641; Fri, 24 May 2024 05:41:12 -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: e7f8bfe5-19ca-11ef-90a1-e314d9c70b13 From: Luca Fancellu To: xen-devel@lists.xenproject.org Cc: Penny Zheng , Stefano Stabellini , Julien Grall , Bertrand Marquis , Michal Orzel , Volodymyr Babchuk , Penny Zheng Subject: [PATCH v4 7/7] xen/docs: Describe static shared memory when host address is not provided Date: Fri, 24 May 2024 13:40:55 +0100 Message-Id: <20240524124055.3871399-8-luca.fancellu@arm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240524124055.3871399-1-luca.fancellu@arm.com> References: <20240524124055.3871399-1-luca.fancellu@arm.com> MIME-Version: 1.0 From: Penny Zheng This commit describe the new scenario where host address is not provided in "xen,shared-mem" property and a new example is added to the page to explain in details. Take the occasion to fix some typos in the page. Signed-off-by: Penny Zheng Signed-off-by: Luca Fancellu Reviewed-by: Michal Orzel --- v2: - Add Michal R-by v1: - patch from https://patchwork.kernel.org/project/xen-devel/patch/20231206090623.1932275-10-Penny.Zheng@arm.com/ with some changes in the commit message. --- docs/misc/arm/device-tree/booting.txt | 52 ++++++++++++++++++++------- 1 file changed, 39 insertions(+), 13 deletions(-) diff --git a/docs/misc/arm/device-tree/booting.txt b/docs/misc/arm/device-tree/booting.txt index bbd955e9c2f6..ac4bad6fe5e0 100644 --- a/docs/misc/arm/device-tree/booting.txt +++ b/docs/misc/arm/device-tree/booting.txt @@ -590,7 +590,7 @@ communication. An array takes a physical address, which is the base address of the shared memory region in host physical address space, a size, and a guest physical address, as the target address of the mapping. - e.g. xen,shared-mem = < [host physical address] [guest address] [size] > + e.g. xen,shared-mem = < [host physical address] [guest address] [size] >; It shall also meet the following criteria: 1) If the SHM ID matches with an existing region, the address range of the @@ -601,8 +601,8 @@ communication. The number of cells for the host address (and size) is the same as the guest pseudo-physical address and they are inherited from the parent node. - Host physical address is optional, when missing Xen decides the location - (currently unimplemented). + Host physical address is optional, when missing Xen decides the location. + e.g. xen,shared-mem = < [guest address] [size] >; - role (Optional) @@ -629,7 +629,7 @@ chosen { role = "owner"; xen,shm-id = "my-shared-mem-0"; xen,shared-mem = <0x10000000 0x10000000 0x10000000>; - } + }; domU1 { compatible = "xen,domain"; @@ -640,25 +640,36 @@ chosen { vpl011; /* - * shared memory region identified as 0x0(xen,shm-id = <0x0>) - * is shared between Dom0 and DomU1. + * shared memory region "my-shared-mem-0" is shared + * between Dom0 and DomU1. */ domU1-shared-mem@10000000 { compatible = "xen,domain-shared-memory-v1"; role = "borrower"; xen,shm-id = "my-shared-mem-0"; xen,shared-mem = <0x10000000 0x50000000 0x10000000>; - } + }; /* - * shared memory region identified as 0x1(xen,shm-id = <0x1>) - * is shared between DomU1 and DomU2. + * shared memory region "my-shared-mem-1" is shared between + * DomU1 and DomU2. */ domU1-shared-mem@50000000 { compatible = "xen,domain-shared-memory-v1"; xen,shm-id = "my-shared-mem-1"; xen,shared-mem = <0x50000000 0x60000000 0x20000000>; - } + }; + + /* + * shared memory region "my-shared-mem-2" is shared between + * DomU1 and DomU2. + */ + domU1-shared-mem-2 { + compatible = "xen,domain-shared-memory-v1"; + xen,shm-id = "my-shared-mem-2"; + role = "owner"; + xen,shared-mem = <0x80000000 0x20000000>; + }; ...... @@ -672,14 +683,21 @@ chosen { cpus = <1>; /* - * shared memory region identified as 0x1(xen,shm-id = <0x1>) - * is shared between domU1 and domU2. + * shared memory region "my-shared-mem-1" is shared between + * domU1 and domU2. */ domU2-shared-mem@50000000 { compatible = "xen,domain-shared-memory-v1"; xen,shm-id = "my-shared-mem-1"; xen,shared-mem = <0x50000000 0x70000000 0x20000000>; - } + }; + + domU2-shared-mem-2 { + compatible = "xen,domain-shared-memory-v1"; + xen,shm-id = "my-shared-mem-2"; + role = "borrower"; + xen,shared-mem = <0x90000000 0x20000000>; + }; ...... }; @@ -699,3 +717,11 @@ shared between DomU1 and DomU2. It will get mapped at 0x60000000 in DomU1 guest physical address space, and at 0x70000000 in DomU2 guest physical address space. DomU1 and DomU2 are both the borrower domain, the owner domain is the default owner domain DOMID_IO. + +For the static shared memory region "my-shared-mem-2", since host physical +address is not provided by user, Xen will automatically allocate 512MB +from heap as static shared memory to be shared between DomU1 and DomU2. +The automatically allocated static shared memory will get mapped at +0x80000000 in DomU1 guest physical address space, and at 0x90000000 in DomU2 +guest physical address space. DomU1 is explicitly defined as the owner domain, +and DomU2 is the borrower domain.