From patchwork Mon Nov 18 17:23:56 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pierrick Bouvier X-Patchwork-Id: 13878899 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.gnu.org (lists.gnu.org [209.51.188.17]) (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 586A5D591A8 for ; Mon, 18 Nov 2024 17:25:28 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1tD5Uc-00005H-VF; Mon, 18 Nov 2024 12:24:55 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1tD5UC-0008Po-OO for qemu-devel@nongnu.org; Mon, 18 Nov 2024 12:24:29 -0500 Received: from mail-pl1-x62b.google.com ([2607:f8b0:4864:20::62b]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1tD5U6-0002q5-JQ for qemu-devel@nongnu.org; Mon, 18 Nov 2024 12:24:27 -0500 Received: by mail-pl1-x62b.google.com with SMTP id d9443c01a7336-20cbcd71012so24157825ad.3 for ; Mon, 18 Nov 2024 09:24:22 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1731950661; x=1732555461; darn=nongnu.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=VBgtkjSEbYTTKzs2OsUJSbyBpcPy82P3Qfcz05KH5DM=; b=f3piH8QrDbQd5MkOWEaSnkPPHq+h//ZK1rCjfYqHyBv/NEfylr4h5UVClFcoukFnpL fLkuMPPz7iXeokJ6bckSRo0k11xrw512ZYNn3bHPzsx+gPbOcCK1n5OJx7UHCSXT/dSP vHVoH29muIQtXokToC6Pih0sEHVRN1/ylJBcKINGzUg8Fzcn4EDWU7XMu05CDOhQjiwN co9dldBNripKSUGzGIn3Hs4Trl7U01m3roJ1DOHF1q6YuytFF2jpHqT5iAzVCbvNC0DH KjNFde1hUM8//AvxPqjf9IjZS8LwaP3z0GGHQt8tQQkaYcOtlLGdsYJAqZBpjmJybrAE y+fA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1731950661; x=1732555461; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=VBgtkjSEbYTTKzs2OsUJSbyBpcPy82P3Qfcz05KH5DM=; b=iufzM1WDfHAwr46F8mo/HRgPKSH2D5WgJ9OzEiUToML+ydE69uoncXPpyWW61GV5Ze bfsY5qWiFs+yVzVwuyRnVhEpFL32dbeiHryeuMNvZVbV4dEnSXMtRdRc1m1cikZ1Vnx7 nAMc157gclYmgfH9vvn1PMT+JzfZxS3mtuEREBN0TdsU0SrsJnCDJ/nJaxZWGo7PmmoF 3gLJYXmJLKnc6beYdhjtU+onrlgLkln6NSI2f5X+C6YoEXPABX4k4H0uSSgbSAwtb2p2 y31XK5dqMtRJ010F02a8UI688uEEqki+kqQ7T3Ot3ne7zHiywjf8ZxivR2DemM4u08XY bzmQ== X-Gm-Message-State: AOJu0YyWeCiaf3X1goUaM5Q5M4Ma5+u4gApR0wlTIeO2r7Md4MhrW/Lm e3hzySclu3AWwokaRUAMYhBhYSpcTDRvLcYahvWw+5zuQ6uhSTA6ERfSn5YHyW4F4Xv5aDM5zDF tbVVnKw== X-Google-Smtp-Source: AGHT+IEtfHUwMv6Qgz1+4IxX3nYSm1Xv9+hPyGeTbVfIa6T3JJYCwtxXSq0Y6cpRHlWh5/YdsgTf/g== X-Received: by 2002:a17:902:d2c1:b0:20c:a174:f77 with SMTP id d9443c01a7336-212348d39c1mr39617695ad.32.1731950660835; Mon, 18 Nov 2024 09:24:20 -0800 (PST) Received: from linaro.. (216-180-64-156.dyn.novuscom.net. [216.180.64.156]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-211d0f55d04sm59469765ad.264.2024.11.18.09.24.19 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 18 Nov 2024 09:24:20 -0800 (PST) From: Pierrick Bouvier To: qemu-devel@nongnu.org Cc: =?utf-8?q?Philippe_Mathieu-Daud=C3=A9?= , Richard Henderson , Andrew Melnychenko , =?utf-8?q?Daniel_P=2E_Berrang=C3=A9?= , Jason Wang , Thomas Huth , alex.bennee@linaro.org, Vladimir Sementsov-Ogievskiy , Fabiano Rosas , Kevin Wolf , Markus Armbruster , Eric Blake , qemu-arm@nongnu.org, Yuri Benditovich , manos.pitsidianakis@linaro.org, qemu-block@nongnu.org, Michael Roth , Konstantin Kostiuk , Paolo Bonzini , Peter Xu , gustavo.romero@linaro.org, Peter Maydell , Pierrick Bouvier Subject: [PATCH 6/7] docs: add a glossary Date: Mon, 18 Nov 2024 09:23:56 -0800 Message-Id: <20241118172357.475281-7-pierrick.bouvier@linaro.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20241118172357.475281-1-pierrick.bouvier@linaro.org> References: <20241118172357.475281-1-pierrick.bouvier@linaro.org> MIME-Version: 1.0 Received-SPF: pass client-ip=2607:f8b0:4864:20::62b; envelope-from=pierrick.bouvier@linaro.org; helo=mail-pl1-x62b.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Signed-off-by: Pierrick Bouvier --- docs/devel/control-flow-integrity.rst | 2 + docs/devel/multi-thread-tcg.rst | 2 + docs/glossary/index.rst | 238 ++++++++++++++++++++++++++ docs/index.rst | 1 + docs/system/arm/virt.rst | 2 + docs/system/images.rst | 2 + docs/tools/qemu-nbd.rst | 2 + 7 files changed, 249 insertions(+) create mode 100644 docs/glossary/index.rst diff --git a/docs/devel/control-flow-integrity.rst b/docs/devel/control-flow-integrity.rst index e6b73a4fe1a..3d5702fa4cc 100644 --- a/docs/devel/control-flow-integrity.rst +++ b/docs/devel/control-flow-integrity.rst @@ -1,3 +1,5 @@ +.. _cfi: + ============================ Control-Flow Integrity (CFI) ============================ diff --git a/docs/devel/multi-thread-tcg.rst b/docs/devel/multi-thread-tcg.rst index d706c27ea74..7fd0a07633d 100644 --- a/docs/devel/multi-thread-tcg.rst +++ b/docs/devel/multi-thread-tcg.rst @@ -4,6 +4,8 @@ This work is licensed under the terms of the GNU GPL, version 2 or later. See the COPYING file in the top-level directory. +.. _mttcg: + ================== Multi-threaded TCG ================== diff --git a/docs/glossary/index.rst b/docs/glossary/index.rst new file mode 100644 index 00000000000..a2d4f3eae16 --- /dev/null +++ b/docs/glossary/index.rst @@ -0,0 +1,238 @@ +.. _Glossary: + +-------- +Glossary +-------- + +This section of the manual presents *simply* acronyms and terms QEMU developers +use. + +Accelerator +----------- + +A specific API used to accelerate execution of guest instructions. It can be +hardware-based, through a virtualization API provided by the host OS (kvm, hvf, +whpx, ...) or software-based (tcg). See this description of `supported +accelerators`. + +Board +----- + +QEMU system defines board models for various architectures. It's a description +of a SoC (system-on-chip) with various devices pre-configured, and can be +selected with the option ``-machine`` of qemu-system. +For virtual machines, you'll use ``virt`` board model, designed for this use +case. As an example, for Arm architecture, you can find the `model code +`_ and +associated `documentation `. + +Block +----- + +Block drivers are the available `disk formats ` available, and +block devices `(see Block device section on options page)` +are using them to implement disks for a virtual machine. + +CFI +--- + +Control Flow Integrity is a hardening technique used to prevent exploits +targeting QEMU by detecting unexpected branches during execution. QEMU `actively +supports` being compiled with CFI enabled. + +Device +------ + +QEMU is able to emulate a CPU, and all the hardware interacting with it, +including many devices. When QEMU runs a virtual machine using a hardware-based +accelerator, it is responsible for emulating, using software, all devices. + +EDK2 +---- + +EDK2, as known as `TianoCore `_, is an open source +implementation of UEFI standard. It's ran by QEMU to support UEFI for virtual +machines. + +gdbstub +------- + +QEMU implements a `gdb server `, allowing gdb to attach to it and +debug a running virtual machine, or a program in user-mode. This allows to debug +a given architecture without having access to hardware. + +glib2 +----- + +`GLib2 `_ is one of the most important library we +are using through the codebase. It provides many data structures, macros, string +and thread utilities and portable functions across different OS. It's required +to build QEMU. + +Guest agent +----------- + +`QEMU Guest agent ` is a daemon intended to be executed by guest +virtual machines and providing various services to help QEMU to interact with +it. + +Guest/Host +---------- + +Guest is the architecture of the virtual machine, which is emulated. +Host is the architecture on which QEMU is running on, which is native. + +Hypervisor +---------- + +The formal definition of an hypervisor is a program than can be used to manage a +virtual machine. QEMU itself is an hypervisor. + +In the context of QEMU, an hypervisor is an API, provided by the Host OS, +allowing to execute virtual machines. Linux implementation is KVM (and supports +Xen as well). For MacOS, it's HVF. Windows defines WHPX. And NetBSD provides +NVMM. + +Migration +--------- + +QEMU can save and restore the execution of a virtual machine, including across +different machines. This is provided by the `Migration framework`. + +NBD +--- + +`QEMU Network Block Device server ` is a tool that can be used to +mount and access QEMU images, providing functionality similar to a loop device. + +Mailing List +------------ + +This is `where `_ all the +development happens! Changes are posted as series, that all developers can +review and share feedback for. + +For reporting issues, our `GitLab +`_ tracker is the best place. + +MMU / softmmu +------------- + +The Memory Management Unit is responsible for translating virtual addresses to +physical addresses and managing memory protection. QEMU system mode is named +"softmmu" precisely because it implements this in software, including a TLB +(Translation lookaside buffer), for the guest virtual machine. + +QEMU user-mode does not implement a full software MMU, but "simply" translates +virtual addresses by adding a specific offset, and relying on host MMU/OS +instead. + +Monitor / QMP / HMP +------------------- + +`QEMU Monitor ` is a text interface which can be used to interact +with a running virtual machine. + +QMP stands for QEMU Monitor Protocol and is a json based interface. +HMP stands for Human Monitor Protocol and is a set of text commands available +for users who prefer natural language to json. + +MTTCG +----- + +Multiple cpus support was first implemented using a round-robin algorithm +running on a single thread. Later on, `Multi-threaded TCG ` was developed +to benefit from multiple cores to speed up execution. + +Plugins +------- + +`TCG Plugins ` is an API used to instrument guest code, in system +and user mode. The end goal is to have a similar set of functionality compared +to `DynamoRIO `_ or `valgrind `_. + +One key advantage of QEMU plugins is that they can be used to perform +architecture agnostic instrumentation. + +Patchwork +--------- + +`Patchwork `_ is a website that tracks +patches on the Mailing List. + +PR +-- + +Once a series is reviewed and accepted by a subsystem maintainer, it will be +included in a PR (Pull Request) that the project maintainer will merge into QEMU +main branch, after running tests. + +QCOW +---- + +QEMU Copy On Write is a disk format developed by QEMU. It provides transparent +compression, automatic extension, and many other advantages over a raw image. + +QEMU +---- + +`QEMU (Quick Emulator) `_ is a generic and open source +machine emulator and virtualizer. + +QOM +--- + +`QEMU Object Model ` is an object oriented API used to define various +devices and hardware in the QEMU codebase. + +Record/replay +------------- + +`Record/replay ` is a feature of QEMU allowing to have a deterministic +and reproducible execution of a virtual machine. + +Rust +---- + +`A new programming language `_, memory safe by +default. We didn't see a more efficient way to create debates and tensions in +a community of C programmers since the birth of C++. + +System mode +----------- + +QEMU System mode emulates a full machine, including its cpu, memory and devices. +It can be accelerated to hardware speed by using one of the hypervisors QEMU +supports. It is referenced as softmmu as well. + +TCG +--- + +`Tiny Code Generator ` is an intermediate representation (IR) used to run +guest instructions on host cpu, with both architectures possibly being +different. + +It is one of the accelerator supported by QEMU, and supports a lot of +guest/host architectures. + +User mode +--------- + +QEMU User mode allows to run programs for a guest architecture, on a host +architecture, by translating system calls and using TCG. It is available for +Linux and BSD. + +VirtIO +------ + +VirtIO is an open standard used to define and implement virtual devices with a +minimal overhead, defining a set of data structures and hypercalls (similar to +system calls, but targeting an hypervisor, which happens to be QEMU in our +case). It's designed to be more efficient than emulating a real device, by +minimizing the amount of interactions between a guest VM and its hypervisor. + +vhost-user +---------- + +`Vhost-user ` is an interface used to implement VirtIO devices +outside of QEMU itself. diff --git a/docs/index.rst b/docs/index.rst index cb5e5098b65..2cad84cd77c 100644 --- a/docs/index.rst +++ b/docs/index.rst @@ -21,3 +21,4 @@ Welcome to QEMU's documentation! specs/index devel/index codebase/index + glossary/index diff --git a/docs/system/arm/virt.rst b/docs/system/arm/virt.rst index e67e7f0f7c5..11ceb898264 100644 --- a/docs/system/arm/virt.rst +++ b/docs/system/arm/virt.rst @@ -1,3 +1,5 @@ +.. _arm-virt: + 'virt' generic virtual platform (``virt``) ========================================== diff --git a/docs/system/images.rst b/docs/system/images.rst index d000bd6b6f1..a5551173c97 100644 --- a/docs/system/images.rst +++ b/docs/system/images.rst @@ -82,4 +82,6 @@ VM snapshots currently have the following known limitations: - A few device drivers still have incomplete snapshot support so their state is not saved or restored properly (in particular USB). +.. _block-drivers: + .. include:: qemu-block-drivers.rst.inc diff --git a/docs/tools/qemu-nbd.rst b/docs/tools/qemu-nbd.rst index 329f44d9895..4f21b7904ac 100644 --- a/docs/tools/qemu-nbd.rst +++ b/docs/tools/qemu-nbd.rst @@ -1,3 +1,5 @@ +.. _qemu-nbd: + ===================================== QEMU Disk Network Block Device Server =====================================