From mboxrd@z Thu Jan 1 00:00:00 1970 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=-20.3 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,URIBL_RED, USER_AGENT_SANE_1 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 7D78BC433E0 for ; Tue, 19 Jan 2021 01:37:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 34584205CB for ; Tue, 19 Jan 2021 01:37:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2392212AbhASBhI (ORCPT ); Mon, 18 Jan 2021 20:37:08 -0500 Received: from mga06.intel.com ([134.134.136.31]:46604 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729202AbhASBhF (ORCPT ); Mon, 18 Jan 2021 20:37:05 -0500 IronPort-SDR: AbVkaheUr/xHEwHVy2k7ZKLIbsLwfu+1y5VDH+ek8HfO0KSWMovMRlukR6l5BRQDifjD6za/FO GbnXp9gDYEdA== X-IronPort-AV: E=McAfee;i="6000,8403,9868"; a="240405321" X-IronPort-AV: E=Sophos;i="5.79,357,1602572400"; d="scan'208";a="240405321" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Jan 2021 17:36:24 -0800 IronPort-SDR: 2gyO3qQfL+vvI06qtcL6hY5xcI+DVuNdyofOeMg3kn0vXpg+Z3ZdvoF38ykX0E7Hz8oPVae1dx PWz68wuF+jdA== X-IronPort-AV: E=Sophos;i="5.79,357,1602572400"; d="scan'208";a="383741805" Received: from shuo-intel.sh.intel.com (HELO localhost) ([10.239.154.30]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Jan 2021 17:36:18 -0800 Date: Tue, 19 Jan 2021 09:36:15 +0800 From: Shuo A Liu To: Randy Dunlap Cc: linux-kernel@vger.kernel.org, x86@kernel.org, Greg Kroah-Hartman , "H . Peter Anvin" , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Yu Wang , Reinette Chatre , Zhi Wang , Borislav Petkov , Dave Hansen , Sen Christopherson , Dan Williams , Fengwei Yin , Zhenyu Wang Subject: Re: [PATCH v7 01/18] docs: acrn: Introduce ACRN Message-ID: <20210119013615.GG22447@shuo-intel.sh.intel.com> References: <20210106075055.47226-1-shuo.a.liu@intel.com> <20210106075055.47226-2-shuo.a.liu@intel.com> <33ff89ab-db2d-ed9c-3632-014870a1c238@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Disposition: inline In-Reply-To: <33ff89ab-db2d-ed9c-3632-014870a1c238@infradead.org> User-Agent: Mutt/1.8.3 (2017-05-23) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Randy, Thanks for review. On Mon 18.Jan'21 at 14:30:51 -0800, Randy Dunlap wrote: >On 1/5/21 11:50 PM, shuo.a.liu@intel.com wrote: >> From: Shuo Liu >> >> Add documentation on the following aspects of ACRN: >> >> 1) A brief introduction on the architecture of ACRN. >> 2) I/O request handling in ACRN. >> 3) CPUID functions of ACRN. >> >> To learn more about ACRN, please go to ACRN project website >> https://projectacrn.org, or the documentation page >> https://projectacrn.github.io/. >> >> Signed-off-by: Shuo Liu >> Reviewed-by: Zhi Wang >> Reviewed-by: Reinette Chatre >> Reviewed-by: Borislav Petkov >> Cc: Dave Hansen >> Cc: Sen Christopherson >> Cc: Dan Williams >> Cc: Fengwei Yin >> Cc: Zhi Wang >> Cc: Zhenyu Wang >> Cc: Yu Wang >> Cc: Reinette Chatre >> Cc: Greg Kroah-Hartman >> Cc: Randy Dunlap >> --- >> Documentation/virt/acrn/cpuid.rst | 46 +++++++++++ >> Documentation/virt/acrn/index.rst | 12 +++ >> Documentation/virt/acrn/introduction.rst | 43 +++++++++++ >> Documentation/virt/acrn/io-request.rst | 97 ++++++++++++++++++++++++ >> Documentation/virt/index.rst | 1 + >> MAINTAINERS | 7 ++ >> 6 files changed, 206 insertions(+) >> create mode 100644 Documentation/virt/acrn/cpuid.rst >> create mode 100644 Documentation/virt/acrn/index.rst >> create mode 100644 Documentation/virt/acrn/introduction.rst >> create mode 100644 Documentation/virt/acrn/io-request.rst >> >> diff --git a/Documentation/virt/acrn/cpuid.rst b/Documentation/virt/acrn/cpuid.rst >> new file mode 100644 >> index 000000000000..16727fc412f0 >> --- /dev/null >> +++ b/Documentation/virt/acrn/cpuid.rst >> @@ -0,0 +1,46 @@ >> +.. SPDX-License-Identifier: GPL-2.0 >> + >> +=============== >> +ACRN CPUID bits >> +=============== >> + >> +A guest VM running on an ACRN hypervisor, can check some of its features using > >comma not needed/not wanted. Removed. > >> +CPUID. >> + >> +ACRN cpuid functions are: >> + >> +function: 0x40000000 >> + >> +returns:: >> + >> + eax = 0x40000010 >> + ebx = 0x4e524341 >> + ecx = 0x4e524341 >> + edx = 0x4e524341 >> + >> +Note that this value in ebx, ecx and edx corresponds to the string >> +"ACRNACRNACRN". The value in eax corresponds to the maximum cpuid function >> +present in this leaf, and will be updated if more functions are added in the > >except for the 0x4000000 bit? It's the maximum cpuid function value. So it's 0x40000010. > >> +future. >> + >> +function: define ACRN_CPUID_FEATURES (0x40000001) >> + >> +returns:: >> + >> + ebx, ecx, edx >> + eax = an OR'ed group of (1 << flag) >> + >> +where ``flag`` is defined as below: >> + >> +================================= =========== ================================ >> +flag value meaning >> +================================= =========== ================================ >> +ACRN_FEATURE_PRIVILEGED_VM 0 guest VM is a privileged VM >> +================================= =========== ================================ >> + >> +function: 0x40000010 >> + >> +returns:: >> + >> + ebx, ecx, edx >> + eax = (Virtual) TSC frequency in kHz. >> diff --git a/Documentation/virt/acrn/index.rst b/Documentation/virt/acrn/index.rst >> new file mode 100644 >> index 000000000000..b5f793e73df5 >> --- /dev/null >> +++ b/Documentation/virt/acrn/index.rst >> @@ -0,0 +1,12 @@ >> +.. SPDX-License-Identifier: GPL-2.0 >> + >> +=============== >> +ACRN Hypervisor >> +=============== >> + >> +.. toctree:: >> + :maxdepth: 1 >> + >> + introduction >> + io-request >> + cpuid >> diff --git a/Documentation/virt/acrn/introduction.rst b/Documentation/virt/acrn/introduction.rst >> new file mode 100644 >> index 000000000000..f8d081bc084d >> --- /dev/null >> +++ b/Documentation/virt/acrn/introduction.rst >> @@ -0,0 +1,43 @@ >> +.. SPDX-License-Identifier: GPL-2.0 >> + >> +ACRN Hypervisor Introduction >> +============================ >> + >> +The ACRN Hypervisor is a Type 1 hypervisor, running directly on bare-metal >> +hardware. It has a privileged management VM, called Service VM, to manage User >> +VMs and do I/O emulation. >> + >> +ACRN userspace is an application running in the Service VM that emulates >> +devices for a User VM based on command line configurations. ACRN Hypervisor >> +Service Module (HSM) is a kernel module in the Service VM which provides >> +hypervisor services to the ACRN userspace. >> + >> +Below figure shows the architecture. >> + >> +:: >> + >> + Service VM User VM >> + +----------------------------+ | +------------------+ >> + | +--------------+ | | | | >> + | |ACRN userspace| | | | | >> + | +--------------+ | | | | >> + |-----------------ioctl------| | | | ... >> + |kernel space +----------+ | | | | >> + | | HSM | | | | Drivers | >> + | +----------+ | | | | >> + +--------------------|-------+ | +------------------+ >> + +---------------------hypercall----------------------------------------+ >> + | ACRN Hypervisor | >> + +----------------------------------------------------------------------+ >> + | Hardware | >> + +----------------------------------------------------------------------+ >> + >> +ACRN userspace allocates memory for the User VM, configures and initializes the >> +devices used by the User VM, loads the virtual bootloader, initializes the >> +virtual CPU state and handles I/O request accesses from the User VM. It uses >> +ioctls to communicate with the HSM. HSM implements hypervisor services by >> +interacting with the ACRN Hypervisor via hypercalls. HSM exports a char device >> +interface (/dev/acrn_hsm) to userspace. >> + >> +The ACRN hypervisor is open for contribution from anyone. The source repo is >> +available at https://github.com/projectacrn/acrn-hypervisor. >> diff --git a/Documentation/virt/acrn/io-request.rst b/Documentation/virt/acrn/io-request.rst >> new file mode 100644 >> index 000000000000..79022a671ea7 >> --- /dev/null >> +++ b/Documentation/virt/acrn/io-request.rst >> @@ -0,0 +1,97 @@ >> +.. SPDX-License-Identifier: GPL-2.0 >> + >> +I/O request handling >> +==================== >> + >> +An I/O request of a User VM, which is constructed by the hypervisor, is >> +distributed by the ACRN Hypervisor Service Module to an I/O client >> +corresponding to the address range of the I/O request. Details of I/O request >> +handling are described in the following sections. >> + >> +1. I/O request >> +-------------- >> + >> +For each User VM, there is a shared 4-KByte memory region used for I/O requests >> +communication between the hypervisor and Service VM. An I/O request is a >> +256-byte structure buffer, which is 'struct acrn_io_request', that is filled by >> +an I/O handler of the hypervisor when a trapped I/O access happens in a User >> +VM. ACRN userspace in the Service VM first allocates a 4-KByte page and passes >> +the GPA (Guest Physical Address) of the buffer to the hypervisor. The buffer is >> +used as an array of 16 I/O request slots with each I/O request slot being 256 >> +bytes. This array is indexed by vCPU ID. >> + >> +2. I/O clients >> +-------------- >> + >> +An I/O client is responsible for handling User VM I/O requests whose accessed >> +GPA falls in a certain range. Multiple I/O clients can be associated with each >> +User VM. There is a special client associated with each User VM, called the >> +default client, that handles all I/O requests that do not fit into the range of >> +any other clients. The ACRN userspace acts as the default client for each User >> +VM. >> + >> +Below illustration shows the relationship between I/O requests shared buffer, >> +I/O requests and I/O clients. >> + >> +:: >> + >> + +------------------------------------------------------+ >> + | Service VM | >> + |+--------------------------------------------------+ | >> + || +----------------------------------------+ | | >> + || | shared page ACRN userspace | | | >> + || | +-----------------+ +------------+ | | | >> + || +----+->| acrn_io_request |<-+ default | | | | >> + || | | | +-----------------+ | I/O client | | | | >> + || | | | | ... | +------------+ | | | >> + || | | | +-----------------+ | | | >> + || | +-|--------------------------------------+ | | >> + ||---|----|-----------------------------------------| | >> + || | | kernel | | >> + || | | +----------------------+ | | >> + || | | | +-------------+ HSM | | | >> + || | +--------------+ | | | | >> + || | | | I/O clients | | | | >> + || | | | | | | | >> + || | | +-------------+ | | | >> + || | +----------------------+ | | >> + |+---|----------------------------------------------+ | >> + +----|-------------------------------------------------+ >> + | >> + +----|-------------------------------------------------+ >> + | +-+-----------+ | >> + | | I/O handler | ACRN Hypervisor | >> + | +-------------+ | >> + +------------------------------------------------------+ >> + >> +3. I/O request state transition >> +------------------------------- >> + >> +The state transitions of an ACRN I/O request are as follows. >> + >> +:: >> + >> + FREE -> PENDING -> PROCESSING -> COMPLETE -> FREE -> ... >> + >> +- FREE: this I/O request slot is empty >> +- PENDING: a valid I/O request is pending in this slot >> +- PROCESSING: the I/O request is being processed >> +- COMPLETE: the I/O request has been processed >> + >> +An I/O request in COMPLETE or FREE state is owned by the hypervisor. HSM and >> +ACRN userspace are in charge of processing the others. >> + >> +4. Processing flow of I/O requests >> +------------------------------- > >add 3 more '-' above, please. Sure. Thanks. shuo