From patchwork Fri Dec 6 19:29:00 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pierrick Bouvier X-Patchwork-Id: 847866 Delivered-To: patch@linaro.org Received: by 2002:a5d:50c2:0:b0:385:e875:8a9e with SMTP id f2csp959577wrt; Fri, 6 Dec 2024 11:30:25 -0800 (PST) X-Forwarded-Encrypted: i=2; AJvYcCXrefS61gmsKT2K9q1M1PthTxJUZTjrr7we4wfiPonUPD1EELGUuBKUvTQ7wE4s9l+ITwO6oA==@linaro.org X-Google-Smtp-Source: AGHT+IEGA4J6yQflrZCHwOUAKfLlPGM/e60Ze+dN+hqAveYDRmzIY3l1lxm88yDVb9l0b6veuO1s X-Received: by 2002:a05:622a:181e:b0:466:a983:a15a with SMTP id d75a77b69052e-46734f70605mr58442431cf.42.1733513425091; Fri, 06 Dec 2024 11:30:25 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1733513425; cv=none; d=google.com; s=arc-20240605; b=a+hLmi3Ice9OgXBSiPPCo7jyscpIXjw+N/DW+1NyAP02CMbJFXlkonFHghqYxsaRTH NgbkAR4mnA0UnhvQmp0hEBa8baAHs110GZrQqQAREhJy0FHSoMPqrRGUuw4NWzz5Kizo izy7hzzERR8/w9ZilYKUvGX8Ig/LLjkzwhcLvDDZXhUM/Arqwl+wk5Xa7p6r+43GNfXi Hnja7xDemTKM4lfpgltzky7BOXHf8QmPMCxyQwzCEbJDd/xze6xpnTcBJYJjkLtxw6O2 chrj284qbSDEoMC7pE2a5nu2/8pOIkINqYw2N0bQtZKLozFBiOMB8YYkYQLfNu4CXD5k KQXg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20240605; h=sender:errors-to:list-subscribe:list-help:list-post:list-archive :list-unsubscribe:list-id:precedence:content-transfer-encoding :mime-version:references:in-reply-to:message-id:date:subject:cc:to :from:dkim-signature; bh=quNdZOi6vs/DfPqpA5a+RAcvgntK93hl6bq6i2nnsOE=; fh=uyWfmQhlxlmFXxA9Akl79dY7oHuR3OlLAm2AMpyXO98=; b=KxwXyO5lOlE4XzsNguNoEuYnd/RaGMY60HzAQ/5Gs1SOoj0pkeEq/wFh0Pu3BmEYKi Cf979+t98n3ur7PC+MedG6BLZat8cp9y8RW5sMGXskn6wnypEnjMsSDksrgw+2YLKTpE whi9v3+cbC0+D7nzGN4tRi5+xmYFi1ggf4MNGZCXhsQBOjvy+lKqsyym10s7zotmQWec sc5ys0fYBVElYUcXnZ+nFR805Ga2ZA9FuVu4xIl3II9snN3L3vmB+wRxPYSGyx0UFA+v yrzW9lutgNizEuJXM5nth1xWpuuHe1qRJ4iuGmHUzuu9csYlOpsrB8PxLjvuwWLiyJ5V L3uw==; dara=google.com ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@linaro.org header.s=google header.b=UarycTlh; spf=pass (google.com: domain of qemu-devel-bounces+patch=linaro.org@nongnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom="qemu-devel-bounces+patch=linaro.org@nongnu.org"; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linaro.org; dara=neutral header.i=@linaro.org Return-Path: Received: from lists.gnu.org (lists.gnu.org. [209.51.188.17]) by mx.google.com with ESMTPS id d75a77b69052e-467297babc9si50672671cf.294.2024.12.06.11.30.24 for (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Fri, 06 Dec 2024 11:30:25 -0800 (PST) Received-SPF: pass (google.com: domain of qemu-devel-bounces+patch=linaro.org@nongnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; Authentication-Results: mx.google.com; dkim=pass header.i=@linaro.org header.s=google header.b=UarycTlh; spf=pass (google.com: domain of qemu-devel-bounces+patch=linaro.org@nongnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom="qemu-devel-bounces+patch=linaro.org@nongnu.org"; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linaro.org; dara=neutral header.i=@linaro.org Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1tJe1Z-0003Ei-5d; Fri, 06 Dec 2024 14:30:01 -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 1tJe0y-0002tm-4J for qemu-devel@nongnu.org; Fri, 06 Dec 2024 14:29:27 -0500 Received: from mail-pf1-x432.google.com ([2607:f8b0:4864:20::432]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1tJe0r-0005Gm-76 for qemu-devel@nongnu.org; Fri, 06 Dec 2024 14:29:22 -0500 Received: by mail-pf1-x432.google.com with SMTP id d2e1a72fcca58-725c49b5e45so671018b3a.2 for ; Fri, 06 Dec 2024 11:29:16 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1733513355; x=1734118155; 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=quNdZOi6vs/DfPqpA5a+RAcvgntK93hl6bq6i2nnsOE=; b=UarycTlhe+mKADcTE11bfOq3slZak4/7/HIyrwoQsZUV/VrGeHS5qC274VfBtwugQY 7NVv76vutpQps+l5MUsIPd7i26v70yM4b1kaaLidm82s7UU/qOR4rRgorzKD/JTapwIp FMbVzYOOMTJ2EBdnj6DRcudMQGe/dkCh1XFS9gNWceRYR7LY+pR6E1m/bk8LLfWbR/Cy a4eGqgNYlSok0pWxKR1ngqx5szFhE7hB3Q5awUvd+vRRr5A03D4BZ/Nf4cxWXLcFKBMx xHEMmVBjEHPInyfIdd6gndU0sU2PDuzRAIC468I7A5HmdJIk4/O10DomkweItXr4SN0i DhPw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1733513355; x=1734118155; 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=quNdZOi6vs/DfPqpA5a+RAcvgntK93hl6bq6i2nnsOE=; b=TrJJpa90Uw9xKq9M+tJzDg58oy9Xz3l0zIbD0VNS7uPukyye1UAZVI5QDrRWuYBW2h 0cCoxjVfUmNHIRb4jlv5pWnnwNxsWMSB2MDZIZZrPLk9k8qGvTZ2hGqdMrWpu6fyzG4L b/m0YEci/9OSi1xp7A1UZpn5h/mKdyN0u4GjbNb29Eg1WUyDu5oFz+r9EPk49R6SQbEc hcUCqD0Da8D2TfYNNdo7A7/W4qQQLg6peZnN3Ze128kYZnMHnRCPlyZPcdnJFtzStS2t cvBvrASSEqghLasZTBlkC6tt0T7JRe7EO2sJCaIhgUd9cU7lpcXmgSwLkat1eL+sWy2I OmjA== X-Gm-Message-State: AOJu0Yw9ABVMbg9xs3YzDP1MSbLqLomfQz6aSyPsv1MlBLdp+VMb5RtV Q1lCdWTXJfwQAI6rRvllN5FtEdVIPJRSgDSu4PLnjxvUs851oQGbbr0Mhzo5lGVJ7zQwxbRmWsc cjCE= X-Gm-Gg: ASbGncuPLvmBajZDQHUcQfjhng0iaALzzoJQNL+cuS71/TjrKl8gKYMfZqcY+sdo/eM tJcgzzSwnbdAAA9HHD+4NIPdsoBtsvBcSbyWNImpC0fgsWM6NiApk+dkgHmVpnvZ+xdswtbZbYD 56cArIyYi+ZpH7NVE6ilsvejO3vmyIDm7SCIZSPXkxWP7lNDaQ/mqWtXYOIgEVDEgWgmUbiEmnW 8kZjhQTio1h4BH74Xux/uBPmh5gwYM1myp4zLcKe+E2QDi5SqypWLK0yTMQV/6nbd0kIOrmdaS2 7Xn4GDI4 X-Received: by 2002:a17:902:c407:b0:215:b45a:6a63 with SMTP id d9443c01a7336-21614d7e213mr58883275ad.32.1733513355310; Fri, 06 Dec 2024 11:29:15 -0800 (PST) Received: from pc.. (216-180-64-156.dyn.novuscom.net. [216.180.64.156]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-215f8ef9fcdsm32110205ad.146.2024.12.06.11.29.14 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 06 Dec 2024 11:29:14 -0800 (PST) From: Pierrick Bouvier To: qemu-devel@nongnu.org Cc: Peter Maydell , =?utf-8?q?Alex_Benn=C3=A9e?= , Richard Henderson , qemu-block@nongnu.org, philmd@linaro.org, Paolo Bonzini , Fabiano Rosas , Vladimir Sementsov-Ogievskiy , =?utf-8?q?Daniel_?= =?utf-8?q?P=2E_Berrang=C3=A9?= , Markus Armbruster , qemu-arm@nongnu.org, Michael Roth , Peter Xu , gustavo.romero@linaro.org, Yuri Benditovich , Eric Blake , Andrew Melnychenko , Konstantin Kostiuk , Kevin Wolf , Thomas Huth , Jason Wang , manos.pitsidianakis@linaro.org, Pierrick Bouvier Subject: [PATCH v3 6/6] docs: add a glossary Date: Fri, 6 Dec 2024 11:29:00 -0800 Message-Id: <20241206192900.3893118-7-pierrick.bouvier@linaro.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20241206192900.3893118-1-pierrick.bouvier@linaro.org> References: <20241206192900.3893118-1-pierrick.bouvier@linaro.org> MIME-Version: 1.0 Received-SPF: pass client-ip=2607:f8b0:4864:20::432; envelope-from=pierrick.bouvier@linaro.org; helo=mail-pf1-x432.google.com X-Spam_score_int: -19 X-Spam_score: -2.0 X-Spam_bar: -- X-Spam_report: (-2.0 / 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, URIBL_SBL_A=0.1 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+patch=linaro.org@nongnu.org Sender: qemu-devel-bounces+patch=linaro.org@nongnu.org Signed-off-by: Pierrick Bouvier --- docs/devel/control-flow-integrity.rst | 2 + docs/devel/multi-thread-tcg.rst | 2 + docs/glossary.rst | 280 ++++++++++++++++++++++++++ docs/index.rst | 1 + docs/system/arm/virt.rst | 2 + docs/system/images.rst | 2 + docs/tools/qemu-nbd.rst | 2 + 7 files changed, 291 insertions(+) create mode 100644 docs/glossary.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.rst b/docs/glossary.rst new file mode 100644 index 00000000000..693d9855dd1 --- /dev/null +++ b/docs/glossary.rst @@ -0,0 +1,280 @@ +.. _Glossary: + +-------- +Glossary +-------- + +This section of the manual presents brief definitions of acronyms and terms used +by QEMU developers. + +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 +----- + +Another name for :ref:`machine`. + +Block +----- + +Block drivers are the available `disk formats and front-ends +` 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 +------ + +In QEMU, a device is a piece of hardware visible to the guest. Examples include +UARTs, PCI controllers, PCI cards, VGA controllers, and many more. + +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. QEMU virtual machines that boot a UEFI firmware +usually use EDK2. + +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 +debugging the guest code that is running inside QEMU. + +glib2 +----- + +`GLib2 `_ is one of the most important libraries 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 +----------- + +The `QEMU Guest Agent ` is a daemon intended to be run within virtual +machines. It provides various services to help QEMU to interact with it. + +.. _guest: + +Guest +----- + +Guest is the architecture of the virtual machine, which is emulated. +See also :ref:`host`. + +Sometimes this is called the :ref:`target` architecture, but that term +can be ambiguous. + +.. _host: + +Host +---- + +Host is the architecture on which QEMU is running on, which is native. +See also :ref:`guest`. + +Hypervisor +---------- + +The formal definition of an hypervisor is a program or API than can be used to +manage a virtual machine. QEMU is a virtualizer, that interacts with various +hypervisors. + +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. + +.. _machine: + +Machine +------- + +QEMU's system emulation models many different types of hardware. A machine model +(sometimes called a board model) is the model of a complete virtual system with +RAM, one or more CPUs, and various devices. It can be selected with the option +``-machine`` of qemu-system. Our machine models can be found on this `page +`. + +Migration +--------- + +QEMU can save and restore the execution of a virtual machine between different +host systems. This is provided by the `Migration framework`. + +NBD +--- + +The `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. + +.. _softmmu: + +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 +------------------- + +The `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 CPU 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. + +Patchew +------- + +`Patchew `_ 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. + +The QEMU project doesn't currently expect most developers to directly submit +pull requests. + +QCOW2 +----- + +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. + +qcow2 is the recommended format to use. + +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. There is a work in progress to integrate it in QEMU codebase for +various subsystems. + +System mode +----------- + +QEMU System mode provides a virtual model of an entire machine (CPU, memory and +emulated devices) to run a guest OS. In this mode the CPU may be fully emulated, +or it may work with a hypervisor such as KVM, Xen or Hypervisor.Framework to +allow the guest to run directly on the host CPU. + +QEMU System mode is called :ref:`softmmu ` as well. + +.. _target: + +Target +------ + +The term "target" can be ambiguous. In most places in QEMU it is used as a +synonym for :ref:`guest`. For example the code for emulating Arm CPUs is in +``target/arm/``. However in the :ref:`TCG subsystem ` "target" refers to the +architecture which QEMU is running on, i.e. the :ref:`host`. + +TCG +--- + +TCG is the QEMU `Tiny Code Generator `. It is the JIT (just-in-time) +compiler we use to emulate a guest CPU in software. + +It is one of the accelerators supported by QEMU, and supports a lot of +guest/host architectures. + +User mode +--------- + +QEMU User mode can launch processes compiled for one CPU on another CPU. In this +mode the CPU is always emulated. In this mode, QEMU translate system calls from +guest to host kernel. 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 78285ebd6a4..5665de85cab 100644 --- a/docs/index.rst +++ b/docs/index.rst @@ -20,3 +20,4 @@ Welcome to QEMU's documentation! interop/index specs/index devel/index + glossary 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 =====================================