From patchwork Fri Jul 19 04:57:33 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: luzhixing12345 X-Patchwork-Id: 1962300 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20230601 header.b=L4ytQxK7; dkim-atps=neutral Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=patchwork.ozlabs.org) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4WQHWC6QFpz20B2 for ; Fri, 19 Jul 2024 14:58:31 +1000 (AEST) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1sUfgw-0003nu-FC; Fri, 19 Jul 2024 00:58:02 -0400 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 1sUfgv-0003mr-0p for qemu-devel@nongnu.org; Fri, 19 Jul 2024 00:58:01 -0400 Received: from mail-pf1-x441.google.com ([2607:f8b0:4864:20::441]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1sUfgs-00082r-HW for qemu-devel@nongnu.org; Fri, 19 Jul 2024 00:58:00 -0400 Received: by mail-pf1-x441.google.com with SMTP id d2e1a72fcca58-70b31272a04so343006b3a.1 for ; Thu, 18 Jul 2024 21:57:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1721365076; x=1721969876; darn=nongnu.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=zPRBGV/CuDOGRpqBmJ8kDagq4x/fn1n7dozwqcVZQds=; b=L4ytQxK7FvQMLsEG/wUGGEcuEpPJglVNZ2eTCB9lK3R0zePfjWTc69QTqipXSGvJND q6WKw54MaK9dIBWM8ya15ybhNsbgYG2wJ7/7SSmvujH4SH2+tDvBB96AMmhmRdhYDA9l N7mpQcRtXLlVNA/z8n8u53WPodq2cz8630TcqPky+J0Gkje7GDrMaghF3vv/tRrMlCUK ivzgqsd4HHqL+SlgMNZ+rIAIvSZgTcxlW7QBmHbgfQRolA2poyi4o7l/3b8bU8RJjG2y F0TGecQYVYefmVRksSfVk04VM85Qu0ukQIuL1QEZ0k3PNntA8acPbAFQoTNAPXIzVtvo LE+Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1721365076; x=1721969876; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=zPRBGV/CuDOGRpqBmJ8kDagq4x/fn1n7dozwqcVZQds=; b=HywkHouCNLOPAKf2x6gkrgfdaEYwCBYTKchvMYQW6zRCoEcYGrc3SDInYNvSjEYj5c k9setCl+V2ucakn1KoAtO4bzNNVhyRSsq1g/E6ZPFF/C76C4B6+vN/6oVGubbTFSBVHW wfTMa7Uegyy2pLxhlDs0nBr0zSDPid079IuJwlZXkMIcbUgH1/3cuSENyFIXq/OJcspI gmcTr04z6uDkJuwpyuSd/HA8RrMq3YqIgXHwc8FYlW7ohHO/q+eAdQqop7KTUovq5iXD vM3tSKdsjuEBAFyc02SQfXWriNsxkRK2vAp6JvpsgL+soY+XpWFfPnXPhu9ZCVdsToS9 lFKA== X-Gm-Message-State: AOJu0YwnMwbjNWj5jXWqZYfkSCKQIHjTGIXB1cYPlbyUvfVCO0SH76Y5 V1D+Volt1pM6fpRZjaGTtoTo4jA1jNHR0S1TtWK9toZd640fz2sHSxsAiick X-Google-Smtp-Source: AGHT+IFOrqX+6QVZZghTxtL0gduGv5mg3MYrQrGCl4VA4cMz/WCFJbodY8jQYsckH5NWJdjrORWzZg== X-Received: by 2002:aa7:8895:0:b0:706:738b:2c3 with SMTP id d2e1a72fcca58-70cfd78cc1cmr2351489b3a.2.1721365076223; Thu, 18 Jul 2024 21:57:56 -0700 (PDT) Received: from localhost.localdomain ([223.104.132.29]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-70cff49141dsm387184b3a.44.2024.07.18.21.57.54 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 18 Jul 2024 21:57:55 -0700 (PDT) From: luzhixing12345 To: qemu-devel@nongnu.org Cc: luzhixing12345 Subject: [PATCH] docs: add more information about CXL2.0 device type Date: Fri, 19 Jul 2024 12:57:33 +0800 Message-Id: <20240719045733.26021-1-luzhixing12345@gmail.com> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 Received-SPF: pass client-ip=2607:f8b0:4864:20::441; envelope-from=luzhixing12345@gmail.com; helo=mail-pf1-x441.google.com X-Spam_score_int: -17 X-Spam_score: -1.8 X-Spam_bar: - X-Spam_report: (-1.8 / 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, FREEMAIL_ENVFROM_END_DIGIT=0.25, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham 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+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Add more information with CXL type1 and type2 devices. Original doc says "May also have device private memory accessible via means such as PCI memory reads and writes to BARs.", but actually CXL type1 devices doesn't have device memory. Signed-off-by: luzhixing12345 --- docs/system/devices/cxl.rst | 18 ++++++------------ 1 file changed, 6 insertions(+), 12 deletions(-) diff --git a/docs/system/devices/cxl.rst b/docs/system/devices/cxl.rst index 882b036f5e..ee50a3c18d 100644 --- a/docs/system/devices/cxl.rst +++ b/docs/system/devices/cxl.rst @@ -46,20 +46,14 @@ CXL 2.0 Device Types -------------------- CXL 2.0 End Points are often categorized into three types. -**Type 1:** These support coherent caching of host memory. Example might -be a crypto accelerators. May also have device private memory accessible -via means such as PCI memory reads and writes to BARs. +**Type 1: Accelerators without device memory**. These support coherent caching of host memory. Example might be a crypto accelerators or smart NICs that use coherency semantics along with PCIe-style DMA transfers. Type1 devices implement a fully coherent cache but no host-managed device memory. -**Type 2:** These support coherent caching of host memory and host -managed device memory (HDM) for which the coherency protocol is managed -by the host. This is a complex topic, so for more information on CXL -coherency see the CXL 2.0 specification. +**Type 2: Accelerators with device memory**. These support coherent caching of host memory and host managed device memory (HDM) for which the coherency protocol is managed by the host. Type 2 devices are accelerators such as GP-GPUs and FPGAs with device memory that can be mapped in part to the cacheable system memory. These devices also cache system memory for processing. -**Type 3 Memory devices:** These devices act as a means of attaching -additional memory (HDM) to a CXL host including both volatile and -persistent memory. The CXL topology may support interleaving across a -number of Type 3 memory devices using HDM Decoders in the host, host -bridge, switch upstream port and endpoints. +**Type 3: Memory devices**. These devices act as a means of attaching +additional memory (HDM) to a CXL host with different memory types, including supporting multiple memory tiers attached to the device with both volatile and persistent memory. The CXL topology may support interleaving across a number of Type 3 memory devices using HDM Decoders in the host, host bridge, switch upstream port and endpoints. + +See more information about CXL.io CXL.cache CXL.mem in the `CXL 2.0 specification `_. Scope of CXL emulation in QEMU ------------------------------