From mboxrd@z Thu Jan 1 00:00:00 1970 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 A05DBC04A95 for ; Thu, 29 Sep 2022 04:03:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Content-Type: Content-Transfer-Encoding:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:From:References:CC:To:Subject: MIME-Version:Date:Message-ID:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=GoMZbbKqV9QKTD4OvgMfkjC2tBK6cG3j3klitDR+BIo=; b=CVQNx/puc3t/W0 RwxZZ9tjM2p4Px1qWDNorlnSR/EOitet3kUIs5ERU7IK7d3tT2uOWcrUuexg1A4sdnqdScUjyqUEV fV/x0pwVGCpryPA5HuyLLkkjo+n1+c2S7+Pzlwpi3FoDBH7Cd3VP9ZbMfDkibZqBN8pbodCuPlfjo NRc0Gu5tqD9rScs1HfyZ3vL0hYUEsckMmWg6GiOGtdIgFr1jiXfx4133J2kYLzX4V2cgSNwKVNkVU YuNxXXdvSGa1iI2fb5SdipJPNr/Bhk+uE+D4JFU38lwlVchzEaGbNpCIInTYpdn8YwnOgIgjwEbbT Bf/9t0k+BbsLbp13XhgA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1odkkk-0017YB-EU; Thu, 29 Sep 2022 04:02:26 +0000 Received: from alexa-out-sd-01.qualcomm.com ([199.106.114.38]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1odkkg-0017X5-ML for linux-arm-kernel@lists.infradead.org; Thu, 29 Sep 2022 04:02:24 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; i=@quicinc.com; q=dns/txt; s=qcdkim; t=1664424142; x=1695960142; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=PQTvPdtfbIJpzPf1F/SRY//WCyK26Mw3kEBkRj9QTyQ=; b=g0815c7RbCu90JVOUohNwRlPGTByo1VYdTKC4YEdhR7WLKPyqrsSBpPU Pq7QrYyJs0JagWGW2oFhKtYE/ZpdAC4EoJVoq1potTAK4DbI8NwWduID1 oPkWjZ0ndgmQHr7jsyKpMMqjBK28qciHiro6jjwb9iK21tzhDZ/izeKd2 I=; Received: from unknown (HELO ironmsg-SD-alpha.qualcomm.com) ([10.53.140.30]) by alexa-out-sd-01.qualcomm.com with ESMTP; 28 Sep 2022 21:02:19 -0700 X-QCInternal: smtphost Received: from nasanex01b.na.qualcomm.com ([10.46.141.250]) by ironmsg-SD-alpha.qualcomm.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Sep 2022 21:02:18 -0700 Received: from [10.110.116.67] (10.80.80.8) by nasanex01b.na.qualcomm.com (10.46.141.250) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.29; Wed, 28 Sep 2022 21:02:17 -0700 Message-ID: Date: Wed, 28 Sep 2022 21:02:17 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.9.1 Subject: Re: [PATCH v4 01/14] docs: gunyah: Introduce Gunyah Hypervisor Content-Language: en-US To: Bagas Sanjaya CC: Bjorn Andersson , Jonathan Corbet , Murali Nalajala , Trilok Soni , Srivatsa Vaddagiri , Carl van Schaik , Andy Gross , Dmitry Baryshkov , Jassi Brar , , "Mark Rutland" , Lorenzo Pieralisi , Sudeep Holla , "Marc Zyngier" , Rob Herring , "Krzysztof Kozlowski" , Will Deacon , Catalin Marinas , Arnd Bergmann , Greg Kroah-Hartman , , , , References: <20220928195633.2348848-1-quic_eberman@quicinc.com> <20220928195633.2348848-2-quic_eberman@quicinc.com> From: Elliot Berman In-Reply-To: X-Originating-IP: [10.80.80.8] X-ClientProxiedBy: nasanex01a.na.qualcomm.com (10.52.223.231) To nasanex01b.na.qualcomm.com (10.46.141.250) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220928_210222_798554_405A4B56 X-CRM114-Status: GOOD ( 32.82 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 9/28/2022 8:43 PM, Bagas Sanjaya wrote: > On Wed, Sep 28, 2022 at 12:56:20PM -0700, Elliot Berman wrote: >> diff --git a/Documentation/virt/gunyah/index.rst b/Documentation/virt/gunyah/index.rst >> new file mode 100644 >> index 000000000000..959f451caccd >> --- /dev/null >> +++ b/Documentation/virt/gunyah/index.rst >> @@ -0,0 +1,114 @@ >> +.. SPDX-License-Identifier: GPL-2.0 >> + >> +================= >> +Gunyah Hypervisor >> +================= >> + >> +.. toctree:: >> + :maxdepth: 1 >> + >> + message-queue >> + >> +Gunyah is a Type-1 hypervisor which is independent of any OS kernel, and runs in >> +a higher CPU privilege level. It does not depend on any lower-privileged operating system >> +for its core functionality. This increases its security and can support a much smaller >> +trusted computing base than a Type-2 hypervisor. >> + >> +Gunyah is an open source hypervisor. The source repo is available at >> +https://github.com/quic/gunyah-hypervisor. >> + >> +Gunyah provides these following features. >> + >> +- Scheduling: >> + >> + A scheduler for virtual CPUs (vCPUs) on physical CPUs and enables time-sharing >> + of the CPUs. Gunyah supports two models of scheduling: >> + >> + 1. "Behind the back" scheduling in which Gunyah hypervisor schedules vCPUS on its own >> + 2. "Proxy" scheduling in which a delegated VM can donate part of one of its vCPU slice >> + to another VM's vCPU via a hypercall. >> + >> +- Memory Management: >> + >> + APIs handling memory, abstracted as objects, limiting direct use of physical >> + addresses. Memory ownership and usage tracking of all memory under its control. >> + Memory partitioning between VMs is a fundamental security feature. >> + >> +- Interrupt Virtualization: >> + >> + Uses CPU hardware interrupt virtualization capabilities. Interrupts are handled >> + in the hypervisor and routed to the assigned VM. >> + >> +- Inter-VM Communication: >> + >> + There are several different mechanisms provided for communicating between VMs. >> + >> +- Virtual platform: >> + >> + Architectural devices such as interrupt controllers and CPU timers are directly provided >> + by the hypervisor as well as core virtual platform devices and system APIs such as ARM PSCI. >> + >> +- Device Virtualization: >> + >> + Para-virtualization of devices is supported using inter-VM communication. >> + >> +Architectures supported >> +======================= >> +AArch64 with a GIC >> + >> +Resources and Capabilities >> +========================== >> + >> +Some services or resources provided by the Gunyah hypervisor are described to a virtual machine by >> +capability IDs. For instance, inter-VM communication is performed with doorbells and message queues. >> +Gunyah allows access to manipulate that doorbell via the capability ID. These devices are described >> +in Linux as a struct gunyah_resource. >> + >> +High level management of these resources is performed by the resource manager VM. RM informs a >> +guest VM about resources it can access through either the device tree or via guest-initiated RPC. >> + >> +For each virtual machine, Gunyah maintains a table of resources which can be accessed by that VM. >> +An entry in this table is called a "capability" and VMs can only access resources via this >> +capability table. Hence, virtual Gunyah devices are referenced by a "capability IDs" and not a >> +"resource IDs". A VM can have multiple capability IDs mapping to the same resource. If 2 VMs have >> +access to the same resource, they may not be using the same capability ID to access that resource >> +since the tables are independent per VM. >> + >> +Resource Manager >> +================ >> + >> +The resource manager (RM) is a privileged application VM supporting the Gunyah Hypervisor. >> +It provides policy enforcement aspects of the virtualization system. The resource manager can >> +be treated as an extension of the Hypervisor but is separated to its own partition to ensure >> +that the hypervisor layer itself remains small and secure and to maintain a separation of policy >> +and mechanism in the platform. On arm64, RM runs at NS-EL1 similar to other virtual machines. >> + >> +Communication with the resource manager from each guest VM happens with message-queue.rst. Details >> +about the specific messages can be found in drivers/virt/gunyah/rsc_mgr.c >> + >> +:: >> + >> + +-------+ +--------+ +--------+ >> + | RM | | VM_A | | VM_B | >> + +-.-.-.-+ +---.----+ +---.----+ >> + | | | | >> + +-.-.-----------.------------.----+ >> + | | \==========/ | | >> + | \========================/ | >> + | Gunyah | >> + +---------------------------------+ >> + >> +The source for the resource manager is available at https://github.com/quic/gunyah-resource-manager. >> + >> +The resource manager provides the following features: >> + >> +- VM lifecycle management: allocating a VM, starting VMs, destruction of VMs >> +- VM access control policy, including memory sharing and lending >> +- Interrupt routing configuration >> +- Forwarding of system-level events (e.g. VM shutdown) to owner VM >> + >> +When booting a virtual machine which uses a devicetree, resource manager overlays a >> +/hypervisor node. This node can let Linux know it is running as a Gunyah guest VM, >> +how to communicate with resource manager, and basic description and capabilities of >> +this VM. See Documentation/devicetree/bindings/firmware/gunyah-hypervisor.yaml for a description >> +of this node. > > The documentation LGTM. > >> diff --git a/Documentation/virt/gunyah/message-queue.rst b/Documentation/virt/gunyah/message-queue.rst >> new file mode 100644 >> index 000000000000..e130f124ed52 >> --- /dev/null >> +++ b/Documentation/virt/gunyah/message-queue.rst >> ... >> +The diagram below shows how message queue works. A typical configuration involves >> +2 message queues. Message queue 1 allows VM_A to send messages to VM_B. Message >> +queue 2 allows VM_B to send messages to VM_A. >> + >> +1. VM_A sends a message of up to 1024 bytes in length. It raises a hypercall >> + with the message to inform the hypervisor to add the message to >> + message queue 1's queue. >> +2. Gunyah raises the corresponding interrupt for VM_B when any of these happens: >> + a. gh_msgq_send has PUSH flag. Queue is immediately flushed. This is the typical case. >> + b. Explicility with gh_msgq_push command from VM_A. >> + c. Message queue has reached a threshold depth. >> +3. VM_B calls gh_msgq_recv and Gunyah copies message to requested buffer. >> + > > The nested list above should be separated with blank lines to be > rendered properly: > > ---- >8 ---- > > diff --git a/Documentation/virt/gunyah/message-queue.rst b/Documentation/virt/gunyah/message-queue.rst > index e130f124ed525a..afaad99db215e6 100644 > --- a/Documentation/virt/gunyah/message-queue.rst > +++ b/Documentation/virt/gunyah/message-queue.rst > @@ -20,9 +20,11 @@ queue 2 allows VM_B to send messages to VM_A. > with the message to inform the hypervisor to add the message to > message queue 1's queue. > 2. Gunyah raises the corresponding interrupt for VM_B when any of these happens: > + > a. gh_msgq_send has PUSH flag. Queue is immediately flushed. This is the typical case. > b. Explicility with gh_msgq_push command from VM_A. > c. Message queue has reached a threshold depth. > + > 3. VM_B calls gh_msgq_recv and Gunyah copies message to requested buffer. > > For VM_B to send a message to VM_A, the process is identical, except that hypercalls > > Thanks. > Thanks! Applied for next version. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel