From patchwork Fri Mar 24 23:08:59 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hao Wu X-Patchwork-Id: 13187468 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 3BD39C6FD1C for ; Fri, 24 Mar 2023 23:10:43 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pfqXe-0002Nl-2q; Fri, 24 Mar 2023 19:09:51 -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 <3tS0eZAgKCrAmkXQejiXWeeWbU.SecgUck-TUlUbdedWdk.ehW@flex--wuhaotsh.bounces.google.com>) id 1pfqXb-0002M7-E9 for qemu-devel@nongnu.org; Fri, 24 Mar 2023 19:09:47 -0400 Received: from mail-pl1-x649.google.com ([2607:f8b0:4864:20::649]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from <3tS0eZAgKCrAmkXQejiXWeeWbU.SecgUck-TUlUbdedWdk.ehW@flex--wuhaotsh.bounces.google.com>) id 1pfqXZ-00083A-ED for qemu-devel@nongnu.org; Fri, 24 Mar 2023 19:09:47 -0400 Received: by mail-pl1-x649.google.com with SMTP id n13-20020a170902d2cd00b001a22d27406bso185627plc.13 for ; Fri, 24 Mar 2023 16:09:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; t=1679699382; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=Wy+QXivZWG6sei776iRdoGPRBV1td8fSYtwRoJlCwUU=; b=k4Qw9cACa6HXj3Gk2wOg8MpoV820+ksu44bZNB2ArjpxFnzkiMLH5ganPC/w40lng1 P4fangQzJj92eWZN0xu1STmHIT4YsLPwQANQ8hEuggy1PwwwMEYIKJo6s1F7qSrsp5VU jecX+ykQrPJAKLiRezuEK08Le9O/iXclVxSAkPYii7V5oyQKoI1rt5nN4dFMXKSp0bPd SLhOoaW5FVd2Jh0aTsYsqU60MSGsbcTe33VsQRUdl9SM0T4tO7AgXk48MGPW64W208hi 48By3ItD/Q8sekYFcxiKzOHagLUV9j/8Lm0T+Rs/5wEUIJApA6SFpPOvtgsOTDjU14O+ U0BQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1679699382; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=Wy+QXivZWG6sei776iRdoGPRBV1td8fSYtwRoJlCwUU=; b=pqiJGWOwT18PSgc8pVsnYE4CPxvbJUzzdXIWVKuS0E6mHKG6Gk+TqbbvhXJtbRTVQ/ xN+85G9qikb51HnRaeDHxKh/hYr7XfXC3hwNQRU4YyjNojiz2GY+5kp2AVnwvdpRBqiK lDaIHM8kFw3fR+skudLR5J/2LHSDtg3F8aDMtCaEDmuU76gsPE6IZK4odaOHja5upgMW ta9pk1GYeFxCQtiFpXOQW/gkTBnI5n1UuQ2NSm4FFx1jKVFbrLLU4JOVtk0piyMixavK gmZpnr8DpGHHH4I7aY5eDmo4QUfGWvTcOd3n/ct1zOIl9bGi0INaxhTkZk2/j07PnxMu sz2g== X-Gm-Message-State: AAQBX9dY/wEm5Q0agxqWmvxoyJimeFkpp1z/dZv7RBPk/ydEUN4HP3wM NHyIJY6O5sOfjCio0gwL/bNwL4HdRkx8aA== X-Google-Smtp-Source: AKy350aOVHC2XY4GZYy8Eh+DoN1w2N4ncy3JS7hWuHc5e48Bk+VCj7mKHjn+hu8iZxl3dwwkANnw1u9enpp5IA== X-Received: from mimik.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:4e]) (user=wuhaotsh job=sendgmr) by 2002:a17:90a:c482:b0:240:1208:a38 with SMTP id j2-20020a17090ac48200b0024012080a38mr1355285pjt.9.1679699381772; Fri, 24 Mar 2023 16:09:41 -0700 (PDT) Date: Fri, 24 Mar 2023 16:08:59 -0700 In-Reply-To: <20230324230904.3710289-1-wuhaotsh@google.com> Mime-Version: 1.0 References: <20230324230904.3710289-1-wuhaotsh@google.com> X-Mailer: git-send-email 2.40.0.348.gf938b09366-goog Message-ID: <20230324230904.3710289-3-wuhaotsh@google.com> Subject: [PATCH v2 2/7] docs/specs: IPMI device emulation: main processor From: Hao Wu To: minyard@acm.org Cc: qemu-arm@nongnu.org, qemu-devel@nongnu.org, wuhaotsh@google.com, venture@google.com, Avi.Fishman@nuvoton.com, kfting@nuvoton.com, hskinnemoen@google.com, titusr@google.com, peter.maydell@linaro.org Received-SPF: pass client-ip=2607:f8b0:4864:20::649; envelope-from=3tS0eZAgKCrAmkXQejiXWeeWbU.SecgUck-TUlUbdedWdk.ehW@flex--wuhaotsh.bounces.google.com; helo=mail-pl1-x649.google.com X-Spam_score_int: -95 X-Spam_score: -9.6 X-Spam_bar: --------- X-Spam_report: (-9.6 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_MED=-0.001, 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, USER_IN_DEF_DKIM_WL=-7.5 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 From: Havard Skinnemoen This document is an attempt to briefly document the existing IPMI emulation support on the main processor. It provides the necessary background for the BMC-side IPMI emulation proposed by the next patch. Signed-off-by: Havard Skinnemoen Signed-off-by: Hao Wu --- docs/specs/index.rst | 1 + docs/specs/ipmi.rst | 100 +++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 101 insertions(+) create mode 100644 docs/specs/ipmi.rst diff --git a/docs/specs/index.rst b/docs/specs/index.rst index a58d9311cb..0b0ff4cbc4 100644 --- a/docs/specs/index.rst +++ b/docs/specs/index.rst @@ -12,6 +12,7 @@ guest hardware that is specific to QEMU. ppc-spapr-xive ppc-spapr-numa acpi_hw_reduced_hotplug + ipmi tpm acpi_hest_ghes acpi_cpu_hotplug diff --git a/docs/specs/ipmi.rst b/docs/specs/ipmi.rst new file mode 100644 index 0000000000..e0badc7f15 --- /dev/null +++ b/docs/specs/ipmi.rst @@ -0,0 +1,100 @@ +===================== +IPMI device emulation +===================== + +QEMU supports emulating many types of machines. This includes machines that may +serve as the main processor in an IPMI system, e.g. x86 or POWER server +processors, as well as machines emulating ARM-based Baseband Management +Controllers (BMCs), e.g. AST2xxx or NPCM7xxx systems-on-chip. + +Main processor emulation +======================== + +A server platform may include one of the following system interfaces for +communicating with a BMC: + +* A Keyboard Controller Style (KCS) Interface, accessible via ISA + (``isa-ipmi-kcs``) or PCI (``pci-ipmi-kcs``). +* A Block Transfer (BT) Interface, accessible via ISA (``isa-ipmi-bt``) or PCI + (``pci-ipmi-bt``). +* An SMBus System Interface (SSIF; ``smbus-ipmi``). + +These interfaces can all be emulated by QEMU. To emulate the behavior of the +BMC, the messaging interface emulators use one of the following backends: + +* A BMC simulator running within the QEMU process (``ipmi-bmc-sim``). +* An external BMC simulator or emulator, connected over a chardev + (``ipmi-bmc-extern``). `ipmi_sim + `_ + from OpenIPMI is an example external BMC emulator. + +The following diagram shows how these entities relate to each other. + +.. blockdiag:: + + blockdiag main_processor_ipmi { + orientation = portrait + default_group_color = "none"; + class msgif [color = lightblue]; + class bmc [color = salmon]; + + ipmi_sim [color="aquamarine", label="External BMC"] + ipmi-bmc-extern <-> ipmi_sim [label="chardev"]; + + group { + orientation = portrait + + ipmi-interface <-> ipmi-bmc; + + group { + orientation = portrait + + ipmi-interface [class = "msgif"]; + isa-ipmi-kcs [class="msgif", stacked]; + + ipmi-interface <- isa-ipmi-kcs [hstyle = generalization]; + } + + + group { + orientation = portrait + + ipmi-bmc [class = "bmc"]; + ipmi-bmc-sim [class="bmc"]; + ipmi-bmc-extern [class="bmc"]; + + ipmi-bmc <- ipmi-bmc-sim [hstyle = generalization]; + ipmi-bmc <- ipmi-bmc-extern [hstyle = generalization]; + } + + } + } + +IPMI System Interfaces +---------------------- + +The system software running on the main processor may use a *system interface* +to communicate with the BMC. These are hardware devices attached to an ISA, PCI +or i2c bus, and in QEMU, they all need to implement ``ipmi-interface-host``. +This allows a BMC implementation to interact with the system interface in a +standard way. + +IPMI BMC +-------- + +The system interface devices delegate emulation of BMC behavior to a BMC +device, that is a subclass of ``ipmi-bmc-host``. This type of device is called +a BMC because that's what it looks like to the main processor guest software. + +The BMC behavior may be simulated within the qemu process (``ipmi-bmc-sim``) or +further delegated to an external emulator, or a real BMC. The +``ipmi-bmc-extern`` device has a required ``chardev`` property which specifies +the communications channel to the external BMC. + +Wire protocol +============= + +The wire protocol used between ``ipmi-bmc-extern`` and the external BMC +emulator is defined by `README.vm +`_ +from the OpenIPMI project.