From patchwork Fri Aug 2 06:49:52 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Akihiko Odaki X-Patchwork-Id: 13751155 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 18609C52D71 for ; Fri, 2 Aug 2024 06:51:57 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1sZm7w-0003SX-Rg; Fri, 02 Aug 2024 02:51:00 -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 1sZm7v-0003My-JS for qemu-devel@nongnu.org; Fri, 02 Aug 2024 02:50:59 -0400 Received: from mail-pj1-x102c.google.com ([2607:f8b0:4864:20::102c]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1sZm7t-0000zv-St for qemu-devel@nongnu.org; Fri, 02 Aug 2024 02:50:59 -0400 Received: by mail-pj1-x102c.google.com with SMTP id 98e67ed59e1d1-2cb4c4de4cbso5285055a91.1 for ; Thu, 01 Aug 2024 23:50:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=daynix-com.20230601.gappssmtp.com; s=20230601; t=1722581456; x=1723186256; darn=nongnu.org; h=cc:to:in-reply-to:references:message-id:content-transfer-encoding :mime-version:subject:date:from:from:to:cc:subject:date:message-id :reply-to; bh=C5Qkc2xHJDIrJ32DpraIz8uFeHLkPAtAdY7nT6vwWJE=; b=AYUeW5JQttS1UCC4MrTrlWb78TURWhHrD1cN291+9hrfSZQgldxT4UL+xq/s0GibiD 7sLh6a445InCci+9NmUFcvjel2Z47JmIYcFnxM4Vb74xBWcvqCa8nOumE4UaTkXFY1tv DNrTVMPEVbxT32Usmlvc/X3lHcKvKAH1Wf8j4uAlw+y00wh0nfgbmNpNyWRTmXMTGgxn VdZI4k/obwWY3sltQ5K07BWcJhsKa81lfkX7OAnOOVeGnd//D+zHbdqN7kX+UtZLKcmv sUfFvMzWAl77l3qZ5snbjYLtu3LMoLAeX8KTnEG6SQRm1qj7ZTPKTZUdZ57qj0a0eFNR BYIA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1722581456; x=1723186256; h=cc:to:in-reply-to:references:message-id:content-transfer-encoding :mime-version:subject:date:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=C5Qkc2xHJDIrJ32DpraIz8uFeHLkPAtAdY7nT6vwWJE=; b=EATFdwlWHBGs/+L44NriEeOiok5o32t4CJFzh82cNOt3vwzfu/hhjD77xtYSUd0rN6 gq4FDET3VCGJaifHN4MYbwGz3b869EP5mmgzsXAibAvdr6RBD8HIq+VLkQ70+lraSATp jpHRWElo7kh/42hckoh17ZEkE3a8HV4Rb30GhXWkvCou1W+/+MrAQCLeeIdrQq3VSO9O acpe+LLQXyUXjn4Z+Jog4Zn+2GI7f9rw6OT2z4OW37yrDK9kwDspMTsQvHKaFdV2EoYI l/MfPXwqDGajj7ufwS/E05+MC9/RJFELiSFzeRK+VvGxI3TAesVFnp76ZdIdqqF4/S3b MYHw== X-Gm-Message-State: AOJu0Yy6SG2mdULsfrRs2Y3cyrhL5tR/7clkpxCdfs2fn9whoj4d4Gs4 t+Ig85qGS5KFZusWPJ6l5TR0ZIwm65x7pPaETMVkbkeHPbpKtqiIoC+4tXdvm4g= X-Google-Smtp-Source: AGHT+IHbP57HzdQgdOoAT09Ovx6+WonHPvuUhuDJfxkQknuIax702CuZfvqS0a4NczNyMxxYXhJA2Q== X-Received: by 2002:a17:90a:e006:b0:2cb:6419:5b53 with SMTP id 98e67ed59e1d1-2cff9475f78mr3375451a91.24.1722581456480; Thu, 01 Aug 2024 23:50:56 -0700 (PDT) Received: from localhost ([157.82.201.15]) by smtp.gmail.com with UTF8SMTPSA id 98e67ed59e1d1-2cffb38d3fcsm1018670a91.50.2024.08.01.23.50.53 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 01 Aug 2024 23:50:56 -0700 (PDT) From: Akihiko Odaki Date: Fri, 02 Aug 2024 15:49:52 +0900 Subject: [PATCH for-9.2 v6 8/9] docs: Document composable SR-IOV device MIME-Version: 1.0 Message-Id: <20240802-sriov-v6-8-0c8ff49c4276@daynix.com> References: <20240802-sriov-v6-0-0c8ff49c4276@daynix.com> In-Reply-To: <20240802-sriov-v6-0-0c8ff49c4276@daynix.com> To: "Michael S. Tsirkin" , Marcel Apfelbaum , Alex Williamson , =?utf-8?q?C=C3=A9dric_Le_Goa?= =?utf-8?q?ter?= , Paolo Bonzini , =?utf-8?q?Daniel_P=2E_Berrang=C3=A9?= , Eduardo Habkost , Jason Wang , Sriram Yagnaraman , Keith Busch , Klaus Jensen Cc: qemu-devel@nongnu.org, qemu-block@nongnu.org, Yui Washizu , Akihiko Odaki X-Mailer: b4 0.14-dev-fd6e3 Received-SPF: none client-ip=2607:f8b0:4864:20::102c; envelope-from=akihiko.odaki@daynix.com; helo=mail-pj1-x102c.google.com X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_NONE=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: Akihiko Odaki --- MAINTAINERS | 1 + docs/system/index.rst | 1 + docs/system/sriov.rst | 36 ++++++++++++++++++++++++++++++++++++ 3 files changed, 38 insertions(+) diff --git a/MAINTAINERS b/MAINTAINERS index e34c2bd4cda2..72b3c6736088 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -2011,6 +2011,7 @@ F: hw/pci-bridge/* F: qapi/pci.json F: docs/pci* F: docs/specs/*pci* +F: docs/system/sriov.rst PCIE DOE M: Huai-Cheng Kuo diff --git a/docs/system/index.rst b/docs/system/index.rst index c21065e51932..718e9d3c56bb 100644 --- a/docs/system/index.rst +++ b/docs/system/index.rst @@ -39,3 +39,4 @@ or Hypervisor.Framework. multi-process confidential-guest-support vm-templating + sriov diff --git a/docs/system/sriov.rst b/docs/system/sriov.rst new file mode 100644 index 000000000000..a851a66a4b8b --- /dev/null +++ b/docs/system/sriov.rst @@ -0,0 +1,36 @@ +.. SPDX-License-Identifier: GPL-2.0-or-later + +Compsable SR-IOV device +======================= + +SR-IOV (Single Root I/O Virtualization) is an optional extended capability of a +PCI Express device. It allows a single physical function (PF) to appear as +multiple virtual functions (VFs) for the main purpose of eliminating software +overhead in I/O from virtual machines. + +There are devices with predefined SR-IOV configurations, but it is also possible +to compose an SR-IOV device yourself. Composing an SR-IOV device is currently +only supported by virtio-net-pci. + +Users can configure an SR-IOV-capable virtio-net device by adding +virtio-net-pci functions to a bus. Below is a command line example: + +.. code-block:: shell + + -netdev user,id=n -netdev user,id=o + -netdev user,id=p -netdev user,id=q + -device pcie-root-port,id=b + -device virtio-net-pci,bus=b,addr=0x0.0x3,netdev=q,sriov-pf=f + -device virtio-net-pci,bus=b,addr=0x0.0x2,netdev=p,sriov-pf=f + -device virtio-net-pci,bus=b,addr=0x0.0x1,netdev=o,sriov-pf=f + -device virtio-net-pci,bus=b,addr=0x0.0x0,netdev=n,id=f + +The VFs specify the paired PF with ``sriov-pf`` property. The PF must be +added after all VFs. It is the user's responsibility to ensure that VFs have +function numbers larger than one of the PF, and that the function numbers +have a consistent stride. + +You may also need to perform additional steps to activate the SR-IOV feature on +your guest. For Linux, refer to [1]_. + +.. [1] https://docs.kernel.org/PCI/pci-iov-howto.html