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 X-Spam-Level: X-Spam-Status: No, score=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 882D0C49EAA for ; Tue, 5 Nov 2019 09:23:58 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 5D74620717 for ; Tue, 5 Nov 2019 09:23:58 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5D74620717 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:41970 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iRv48-0002lv-VW for qemu-devel@archiver.kernel.org; Tue, 05 Nov 2019 04:23:57 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:44156) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iRuwN-0001p2-AG for qemu-devel@nongnu.org; Tue, 05 Nov 2019 04:16:01 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iRuwL-0002Pv-BR for qemu-devel@nongnu.org; Tue, 05 Nov 2019 04:15:55 -0500 Received: from szxga07-in.huawei.com ([45.249.212.35]:56026 helo=huawei.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1iRuwH-0002LV-E6; Tue, 05 Nov 2019 04:15:49 -0500 Received: from DGGEMS412-HUB.china.huawei.com (unknown [172.30.72.58]) by Forcepoint Email with ESMTP id 140828AB8BB749B6CA1E; Tue, 5 Nov 2019 17:15:47 +0800 (CST) Received: from [127.0.0.1] (10.133.216.73) by DGGEMS412-HUB.china.huawei.com (10.3.19.212) with Microsoft SMTP Server id 14.3.439.0; Tue, 5 Nov 2019 17:15:39 +0800 Subject: Re: [RFC v2 00/14] Add SDEI support for arm64 To: , References: <20191105091056.9541-1-guoheyi@huawei.com> From: Guoheyi Message-ID: <5bea63bb-9898-146e-f664-283459c86b84@huawei.com> Date: Tue, 5 Nov 2019 17:15:37 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.7.1 MIME-Version: 1.0 In-Reply-To: <20191105091056.9541-1-guoheyi@huawei.com> Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.133.216.73] X-CFilter-Loop: Reflected X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 45.249.212.35 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Peter Maydell , "Michael S. Tsirkin" , Marc Zyngier , Cornelia Huck , Shannon Zhao , Igor Mammedov , James Morse , Paolo Bonzini , wanghaibin.wang@huawei.com, Dave Martin Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 2019/11/5 17:10, Heyi Guo wrote: > SDEI is for ARM "Software Delegated Exception Interface". AS ARM64 doesn't have > native non-maskable interrupt (NMI), we rely on higher privileged (larger > exception level) software to change the execution flow of lower privileged > (smaller exception level) software when certain events occur, to emulate NMI > mechanism, and SDEI is the standard interfaces between the two levels of > privileged software. It is based on SMC/HVC calls. Sorry I forgot to attach the link of SDEI specification v1.0: http://infocenter.arm.com/help/topic/com.arm.doc.den0054a/ARM_DEN0054A_Software_Delegated_Exception_Interface.pdf > > The higher privileged software implements an SDEI dispatcher to handle SDEI > related SMC/HVC calls and trigger SDEI events; the lower privileged software > implements an SDEI client to request SDEI services and handle SDEI events. > > Core interfaces provided by SDEI include: > > 1. interrupt bind: client can request to bind an interrupt to an SDEI event, so > the interrupt will be a non-maskable event and the event number will be returned > to the caller. Only PPI and SPI can be bound to SDEI events. > > 2. register: client can request to register a handler to an SDEI event, so > dispatcher will change PC of lower privileged software to this handler when > certain event occurs. > > 3. complete: client notifies dispatcher that it has completed the event > handling, so dispatcher will restore the context of guest when it is > interrupted. > > In virtualization situation, guest OS is the lower privileged software and > hypervisor is the higher one. > > KVM is supposed to pass SMC/HVC calls to qemu, and qemu will emulate an SDEI > dispatcher to serve the SDEI requests and trigger the events. If an interrupt is > requested to be bound to an event, qemu should not inject the interrupt to guest > any more; instead, it should save the context of VCPU and change the PC to event > handler which is registered by guest, and then return to guest. > > To make the conversion of interrupt to SDEI event transparent to other modules > in qemu, we used qemu_irq and qemu_irq_intercept_in() to override the default > irq handler with SDEI event trigger. I saw qemu_irq_intercept_in() should be > only used in qemu MST, but it seemed fit to override interrupt injection with > event trigger after guest requests to bind interrupt to SDEI event. > > This patchset is trying to implement the whole SDEI framework in qemu with KVM > enabled, including all SDEI v1.0 interfaces, as well as event trigger conduit > from other qemu devices after interrupt binding. > > Key points: > - We propose to only support kvm enabled arm64 virtual machines, for > non-kvm VMs can emulate EL3 and have Trusted Firmware run on it, > which has a builtin SDEI dispatcher. > - New kvm capability KVM_CAP_FORWARD_HYPERCALL is added to probe if > kvm supports forwarding hypercalls, and the capability should be > enabled explicitly. > - We make the dispatcher as a logical device, to save the states > during migration or save/restore operation; only one instance is > allowed in one VM. > - We use qemu_irq as the bridge for other qemu modules to switch from > irq injection to SDEI event trigger after VM binds the interrupt to > SDEI event. We use qemu_irq_intercept_in() to override qemu_irq > handler with SDEI event trigger, and a new interface > qemu_irq_remove_intercept() is added to restore the handler to > default one (i.e. ARM GIC). > > More details are in the commit message of each patch. > > Basic tests are done by emulating a watchdog timer and triggering SDEI > event in every 10s. > > Please focus on the interfaces and framework first. We can refine the code for > several rounds after the big things have been determined. > > Any comment or suggestion is welcome. > > Thanks, > > HG > > Cc: Peter Maydell > Cc: Dave Martin > Cc: Marc Zyngier > Cc: Mark Rutland > Cc: James Morse > Cc: "Michael S. Tsirkin" > Cc: Cornelia Huck > Cc: Paolo Bonzini > Cc: Shannon Zhao > Cc: Igor Mammedov > > v2: > - Import import linux/arm_sdei.h to standard-headers > - Drop SDEI table definition and add comments > - Some bugfix and code refinement > > Heyi Guo (14): > update-linux-headers.sh: import linux/arm_sdei.h to standard-headers > standard-headers: import arm_sdei.h > arm/sdei: add virtual device framework > arm: add CONFIG_SDEI build flag > arm/sdei: add support to handle SDEI requests from guest > arm/sdei: add system reset callback > arm/sdei: add support to trigger event by GIC interrupt ID > core/irq: add qemu_irq_remove_intercept interface > arm/sdei: override qemu_irq handler when binding interrupt > arm/sdei: add support to register interrupt bind notifier > linux-headers/kvm.h: add capability to forward hypercall > arm/sdei: add stub to fix build failure when SDEI is not enabled > arm/kvm: handle guest exit of hypercall > virt/acpi: add SDEI table if SDEI is enabled > > default-configs/arm-softmmu.mak | 1 + > hw/arm/Kconfig | 4 + > hw/arm/virt-acpi-build.c | 26 + > hw/core/irq.c | 11 + > include/hw/irq.h | 8 +- > include/standard-headers/linux/arm_sdei.h | 73 + > linux-headers/linux/kvm.h | 1 + > scripts/update-linux-headers.sh | 1 + > target/arm/Makefile.objs | 4 + > target/arm/kvm.c | 17 + > target/arm/sdei-stub.c | 49 + > target/arm/sdei.c | 1576 +++++++++++++++++++++ > target/arm/sdei.h | 60 + > target/arm/sdei_int.h | 121 ++ > 14 files changed, 1950 insertions(+), 2 deletions(-) > create mode 100644 include/standard-headers/linux/arm_sdei.h > create mode 100644 target/arm/sdei-stub.c > create mode 100644 target/arm/sdei.c > create mode 100644 target/arm/sdei.h > create mode 100644 target/arm/sdei_int.h >