From patchwork Tue Apr 6 10:36:03 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luca Fancellu X-Patchwork-Id: 12184809 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-21.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 05C5FC43460 for ; Tue, 6 Apr 2021 10:37:21 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 9D780613A0 for ; Tue, 6 Apr 2021 10:37:20 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9D780613A0 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from list by lists.xenproject.org with outflank-mailman.105771.202320 (Exim 4.92) (envelope-from ) id 1lTj57-00015I-7A; Tue, 06 Apr 2021 10:37:13 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 105771.202320; Tue, 06 Apr 2021 10:37:13 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lTj57-000159-3i; Tue, 06 Apr 2021 10:37:13 +0000 Received: by outflank-mailman (input) for mailman id 105771; Tue, 06 Apr 2021 10:37:12 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lTj56-00014T-14 for xen-devel@lists.xenproject.org; Tue, 06 Apr 2021 10:37:12 +0000 Received: from foss.arm.com (unknown [217.140.110.172]) by us1-rack-iad1.inumbo.com (Halon) with ESMTP id 4a834dd7-fed1-4812-baa5-2a2f380abfc6; Tue, 06 Apr 2021 10:37:10 +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 F0CC2ED1; Tue, 6 Apr 2021 03:37:09 -0700 (PDT) Received: from e125770.cambridge.arm.com (e125770.cambridge.arm.com [10.1.197.16]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id A022A3F73D; Tue, 6 Apr 2021 03:37:08 -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: 4a834dd7-fed1-4812-baa5-2a2f380abfc6 From: Luca Fancellu To: xen-devel@lists.xenproject.org Cc: bertrand.marquis@arm.com, wei.chen@arm.com, Andrew Cooper , George Dunlap , Ian Jackson , Jan Beulich , Julien Grall , Stefano Stabellini , Wei Liu Subject: [PATCH 3/3] docs/doxygen: doxygen documentation for grant_table.h Date: Tue, 6 Apr 2021 11:36:03 +0100 Message-Id: <20210406103603.8530-4-luca.fancellu@arm.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20210406103603.8530-1-luca.fancellu@arm.com> References: <20210406103603.8530-1-luca.fancellu@arm.com> Modification to include/public/grant_table.h: 1) Change anonymous structure to be named structure, because doxygen can't deal with them. 2) Add doxygen tags to: - Create Grant tables section - include variables in the generated documentation 3) Add .rst file for grant table for Arm64 Signed-off-by: Luca Fancellu --- docs/hypercall-interfaces/arm64.rst | 1 + .../arm64/grant_tables.rst | 8 ++ docs/xen-doxygen/doxy_input.list | 1 + xen/include/public/grant_table.h | 79 ++++++++++++------- 4 files changed, 59 insertions(+), 30 deletions(-) create mode 100644 docs/hypercall-interfaces/arm64/grant_tables.rst diff --git a/docs/hypercall-interfaces/arm64.rst b/docs/hypercall-interfaces/arm64.rst index 5e701a2adc..c30a7142b1 100644 --- a/docs/hypercall-interfaces/arm64.rst +++ b/docs/hypercall-interfaces/arm64.rst @@ -8,6 +8,7 @@ Starting points .. toctree:: :maxdepth: 2 + arm64/grant_tables Functions diff --git a/docs/hypercall-interfaces/arm64/grant_tables.rst b/docs/hypercall-interfaces/arm64/grant_tables.rst new file mode 100644 index 0000000000..8955ec5812 --- /dev/null +++ b/docs/hypercall-interfaces/arm64/grant_tables.rst @@ -0,0 +1,8 @@ +.. SPDX-License-Identifier: CC-BY-4.0 + +Grant Tables +============ + +.. doxygengroup:: grant_table + :project: Xen + :members: diff --git a/docs/xen-doxygen/doxy_input.list b/docs/xen-doxygen/doxy_input.list index e69de29bb2..233d692fa7 100644 --- a/docs/xen-doxygen/doxy_input.list +++ b/docs/xen-doxygen/doxy_input.list @@ -0,0 +1 @@ +xen/include/public/grant_table.h diff --git a/xen/include/public/grant_table.h b/xen/include/public/grant_table.h index 84b1d26b36..b506e09ed3 100644 --- a/xen/include/public/grant_table.h +++ b/xen/include/public/grant_table.h @@ -25,15 +25,19 @@ * Copyright (c) 2004, K A Fraser */ -#ifndef __XEN_PUBLIC_GRANT_TABLE_H__ +/** + * @file + * @brief Interface for granting foreign access to page frames, and receiving + * page-ownership transfers. + */ + +#if !defined(__XEN_PUBLIC_GRANT_TABLE_H__) || defined(DOXYGEN) #define __XEN_PUBLIC_GRANT_TABLE_H__ #include "xen.h" -/* - * `incontents 150 gnttab Grant Tables - * - * Xen's grant tables provide a generic mechanism to memory sharing +/** + * @brief Xen's grant tables provide a generic mechanism to memory sharing * between domains. This shared memory interface underpins the split * device drivers for block and network IO. * @@ -51,13 +55,10 @@ * know the real machine address of a page it is sharing. This makes * it possible to share memory correctly with domains running in * fully virtualised memory. - */ - -/*********************************** + * * GRANT TABLE REPRESENTATION - */ - -/* Some rough guidelines on accessing and updating grant-table entries + * + * Some rough guidelines on accessing and updating grant-table entries * in a concurrency-safe manner. For more information, Linux contains a * reference implementation for guest OSes (drivers/xen/grant_table.c, see * http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=blob;f=drivers/xen/grant-table.c;hb=HEAD @@ -66,6 +67,7 @@ * compiler barrier will still be required. * * Introducing a valid entry into the grant table: + * @code * 1. Write ent->domid. * 2. Write ent->frame: * GTF_permit_access: Frame to which access is permitted. @@ -73,20 +75,25 @@ * frame, or zero if none. * 3. Write memory barrier (WMB). * 4. Write ent->flags, inc. valid type. + * @endcode * * Invalidating an unused GTF_permit_access entry: + * @code * 1. flags = ent->flags. * 2. Observe that !(flags & (GTF_reading|GTF_writing)). * 3. Check result of SMP-safe CMPXCHG(&ent->flags, flags, 0). * NB. No need for WMB as reuse of entry is control-dependent on success of * step 3, and all architectures guarantee ordering of ctrl-dep writes. + * @endcode * * Invalidating an in-use GTF_permit_access entry: + * * This cannot be done directly. Request assistance from the domain controller * which can set a timeout on the use of a grant entry and take necessary * action. (NB. This is not yet implemented!). * * Invalidating an unused GTF_accept_transfer entry: + * @code * 1. flags = ent->flags. * 2. Observe that !(flags & GTF_transfer_committed). [*] * 3. Check result of SMP-safe CMPXCHG(&ent->flags, flags, 0). @@ -97,47 +104,55 @@ * transferred frame is written. It is safe for the guest to spin waiting * for this to occur (detect by observing GTF_transfer_completed in * ent->flags). + * @endcode * * Invalidating a committed GTF_accept_transfer entry: * 1. Wait for (ent->flags & GTF_transfer_completed). * * Changing a GTF_permit_access from writable to read-only: + * * Use SMP-safe CMPXCHG to set GTF_readonly, while checking !GTF_writing. * * Changing a GTF_permit_access from read-only to writable: + * * Use SMP-safe bit-setting instruction. - */ - -/* - * Reference to a grant entry in a specified domain's grant table. - */ -typedef uint32_t grant_ref_t; - -/* + * * A grant table comprises a packed array of grant entries in one or more * page frames shared between Xen and a guest. + * * [XEN]: This field is written by Xen and read by the sharing guest. + * * [GST]: This field is written by the guest and read by Xen. + * + * @addtogroup grant_table Grant Tables + * @{ */ -/* - * Version 1 of the grant table entry structure is maintained purely - * for backwards compatibility. New guests should use version 2. +/** + * Reference to a grant entry in a specified domain's grant table. */ +typedef uint32_t grant_ref_t; + #if __XEN_INTERFACE_VERSION__ < 0x0003020a #define grant_entry_v1 grant_entry #define grant_entry_v1_t grant_entry_t #endif +/** + * Version 1 of the grant table entry structure is maintained purely + * for backwards compatibility. New guests should use version 2. + */ struct grant_entry_v1 { - /* GTF_xxx: various type and flag information. [XEN,GST] */ + /** GTF_xxx: various type and flag information. [XEN,GST] */ uint16_t flags; - /* The domain being granted foreign privileges. [GST] */ + /** The domain being granted foreign privileges. [GST] */ domid_t domid; - /* + /** + * @code * GTF_permit_access: GFN that @domid is allowed to map and access. [GST] * GTF_accept_transfer: GFN that @domid is allowed to transfer into. [GST] * GTF_transfer_completed: MFN whose ownership transferred by @domid * (non-translated guests only). [XEN] + * @endcode */ uint32_t frame; }; @@ -243,7 +258,7 @@ union grant_entry_v2 { * In that case, the frame field has the same semantics as the * field of the same name in the V1 entry structure. */ - struct { + struct full_page { grant_entry_header_t hdr; uint32_t pad0; uint64_t frame; @@ -254,7 +269,7 @@ union grant_entry_v2 { * @domid is allowed to access bytes [@page_off,@page_off+@length) * in frame @frame. */ - struct { + struct sub_page { grant_entry_header_t hdr; uint16_t page_off; uint16_t length; @@ -270,7 +285,7 @@ union grant_entry_v2 { * The current version of Xen does not allow transitive grants * to be mapped. */ - struct { + struct transitive { grant_entry_header_t hdr; domid_t trans_domid; uint16_t pad0; @@ -459,7 +474,7 @@ DEFINE_XEN_GUEST_HANDLE(gnttab_transfer_t); struct gnttab_copy { /* IN parameters. */ struct gnttab_copy_ptr { - union { + union gnttab_copy_ptr_u { grant_ref_t ref; xen_pfn_t gmfn; } u; @@ -584,7 +599,7 @@ DEFINE_XEN_GUEST_HANDLE(gnttab_swap_grant_ref_t); * page granted to the calling domain by a foreign domain. */ struct gnttab_cache_flush { - union { + union a { uint64_t dev_bus_addr; grant_ref_t ref; } a; @@ -673,6 +688,10 @@ DEFINE_XEN_GUEST_HANDLE(gnttab_cache_flush_t); "operation not done; try again" \ } +/** + * @} +*/ + #endif /* __XEN_PUBLIC_GRANT_TABLE_H__ */ /*