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=-10.5 required=3.0 tests=BAYES_00,INCLUDES_CR_TRAILER, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 7510EC433DB for ; Tue, 2 Feb 2021 18:19:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 48EC364F68 for ; Tue, 2 Feb 2021 18:19:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238479AbhBBSS6 (ORCPT ); Tue, 2 Feb 2021 13:18:58 -0500 Received: from mail-wr1-f54.google.com ([209.85.221.54]:38015 "EHLO mail-wr1-f54.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238366AbhBBSQp (ORCPT ); Tue, 2 Feb 2021 13:16:45 -0500 Received: by mail-wr1-f54.google.com with SMTP id b3so3365596wrj.5; Tue, 02 Feb 2021 10:16:28 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=FCp+C+rgPYZTZ229hkCWEYMMpy6/7MzmueKWQdI985s=; b=AV298+j1AiOz73Ta9LuHBF/a4+s40toGw8rx4Ge35ATNTNQ1Bs8Jwv8HEHs5A6nNUW 0enZabyNCwuiSvjW6XPVLZuGg8JOdpHOmx2bP3x3Lkzzu70gp7tziRM83sQohottoK3v AkY6uR1J5BzFKMLMcev9oratFZoJp6egTS/gZADHzFeRr+7oF8eWIs3PaIQIBp1yY3HU nwsoBXnvyCImhNV5P9EJTBEMES+kVFKgcYuAAIEoVUR0NgcgNYpJDPGNANy1SMfbOU4U 2LUO+M/r0GCG7tvucm1KYbb1nb0WqSM85iWpqhFc0D4fQrgUhRaRUgvakp7WTkqKW9oc jVoA== X-Gm-Message-State: AOAM53377A6xRl0XZnRSlxNRAOc5h1IcZj51G9cWNJlgI7V3eQQQA/j7 FXH92/o7NEDl3s9FwrVFjv4= X-Google-Smtp-Source: ABdhPJzm1+hIiMOhMVNoFIodRo9Vswj4u0lg6rRTh7uPnqz7H7LD3Ip2YXrB+ZXKnVMQ9OPhiXifIA== X-Received: by 2002:adf:902a:: with SMTP id h39mr24929214wrh.147.1612289761909; Tue, 02 Feb 2021 10:16:01 -0800 (PST) Received: from liuwe-devbox-debian-v2 ([51.145.34.42]) by smtp.gmail.com with ESMTPSA id r11sm4433342wmh.9.2021.02.02.10.16.01 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 02 Feb 2021 10:16:01 -0800 (PST) Date: Tue, 2 Feb 2021 18:16:00 +0000 From: Wei Liu To: Michael Kelley Cc: Wei Liu , Linux on Hyper-V List , "virtualization@lists.linux-foundation.org" , Linux Kernel List , Vineeth Pillai , Sunil Muthuswamy , Nuno Das Neves , "pasha.tatashin@soleen.com" , KY Srinivasan , Haiyang Zhang , Stephen Hemminger , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)" , "H. Peter Anvin" Subject: Re: [PATCH v5 15/16] x86/hyperv: implement an MSI domain for root partition Message-ID: <20210202181600.4lk4zber7dogsd6e@liuwe-devbox-debian-v2> References: <20210120120058.29138-1-wei.liu@kernel.org> <20210120120058.29138-16-wei.liu@kernel.org> <20210202173153.jkbvwck2vsjlbjbz@liuwe-devbox-debian-v2> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20180716 Precedence: bulk List-ID: X-Mailing-List: linux-hyperv@vger.kernel.org On Tue, Feb 02, 2021 at 06:15:23PM +0000, Michael Kelley wrote: > From: Wei Liu Sent: Tuesday, February 2, 2021 9:32 AM > > > > On Wed, Jan 27, 2021 at 05:47:04AM +0000, Michael Kelley wrote: > > > From: Wei Liu Sent: Wednesday, January 20, 2021 4:01 AM > > > > > > > > When Linux runs as the root partition on Microsoft Hypervisor, its > > > > interrupts are remapped. Linux will need to explicitly map and unmap > > > > interrupts for hardware. > > > > > > > > Implement an MSI domain to issue the correct hypercalls. And initialize > > > > this irqdomain as the default MSI irq domain. > > > > > > > > Signed-off-by: Sunil Muthuswamy > > > > Co-Developed-by: Sunil Muthuswamy > > > > Signed-off-by: Wei Liu > > > > --- > > > > v4: Fix compilation issue when CONFIG_PCI_MSI is not set. > > > > v3: build irqdomain.o for 32bit as well. > > > > > > I'm not clear on the intent for 32-bit builds. Given that hv_proc.c is built > > > only for 64-bit, I'm assuming running Linux in the root partition > > > is only functional for 64-bit builds. So is the goal simply that 32-bit > > > builds will compile correctly? Seems like maybe there should be > > > a CONFIG option for running Linux in the root partition, and that > > > option would force 64-bit. > > > > To ensure 32 bit kernel builds and 32 bit guests still work. > > > > The config option ROOT_API is to be introduced by Nuno's /dev/mshv > > series. We can use that option to gate some objects when that's > > available. > > > > But just so I'm 100% clear, is there intent to run 32-bit Linux in the root > partition? I'm assuming not. That's correct. There is no intent to run 32-bit Linux as the root partition. Wei. > > Michael