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=-11.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=unavailable 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 3DC13C433DB for ; Wed, 10 Feb 2021 17:45:23 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (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 D81B164ECF for ; Wed, 10 Feb 2021 17:45:22 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D81B164ECF Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date:Message-ID:From: References:To:Subject:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=HuiOM7cbtLiV4gMLfsH/embvsXZmW0ecxdjOhoDGTxY=; b=gKelEpXdNo3MiELySFIpKLcGG Qdz3R3yy7Iqcf/PnyfgdF4Pia7zRHAD+Dz0f6o+zCsifkiIE1kRq/KJ+hD0zByCjSFKOXHZZr9eYV p+QBdd5wcG/iD08fCBGALb0uYIN5x19b1I9AI6nS1uiG3FlNKoZvX1nWxVJNEJZFqruYQReS+VvkN nWzbCz40aYK/m3RVXkuIW41tWpof5W3gFXyYp5I8JbAI8a+MV1nj6etdjnMZM8OMfzPTn91lTrlRb G37Cv7GUPOusSuD33GD6IpJEztGHjZvaI/wo5JJCpUV/Jf9n48OgTbIe3y7QJRvC7B3NEBhc50E3H dWa6fCn2Q==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1l9tXF-0006wK-M8; Wed, 10 Feb 2021 17:44:17 +0000 Received: from foss.arm.com ([217.140.110.172]) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1l9tXD-0006vZ-Gl for linux-arm-kernel@lists.infradead.org; Wed, 10 Feb 2021 17:44:16 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 21FC0ED1; Wed, 10 Feb 2021 09:44:11 -0800 (PST) Received: from [192.168.0.110] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 225623F73B; Wed, 10 Feb 2021 09:44:10 -0800 (PST) Subject: Re: [PATCH kvmtool 00/21] Unify I/O port and MMIO trap handling To: Andre Przywara , Will Deacon , Julien Thierry References: <20201210142908.169597-1-andre.przywara@arm.com> From: Alexandru Elisei Message-ID: <889e3627-9f95-6349-5511-d06314e8cbdd@arm.com> Date: Wed, 10 Feb 2021 17:44:21 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.7.0 MIME-Version: 1.0 In-Reply-To: <20201210142908.169597-1-andre.przywara@arm.com> Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210210_124415_663576_56AB5C35 X-CRM114-Status: GOOD ( 27.48 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-arm-kernel@lists.infradead.org, Marc Zyngier , kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi Andre, On 12/10/20 2:28 PM, Andre Przywara wrote: > At the moment we use two separate code paths to handle exits for > KVM_EXIT_IO (ioport.c) and KVM_EXIT_MMIO (mmio.c), even though they > are semantically very similar. Because the trap handler callback routine > is different, devices need to decide on one conduit or need to provide > different handler functions for both of them. > > This is not only unnecessary code duplication, but makes switching > devices from I/O port to MMIO a tedious task, even though there is no > real difference between the two, especially on ARM and PowerPC. > > For ARM we aim at providing a flexible memory layout, and also have > trouble with the UART and RTC device overlapping with the PCI I/O area, > so it seems indicated to tackle this once and for all. > > The first three patches do some cleanup, to simplify things later. > > Patch 04/21 lays the groundwork, by extending mmio.c to be able to also > register I/O port trap handlers, using the same callback prototype as > we use for MMIO. > > The next 14 patches then convert devices that use the I/O port > interface over to the new joint interface. This requires to rework > the trap handler routine to adhere to the same prototype as the existing > MMIO handlers. For most devices this is done in two steps: a first to > introduce the reworked handler routine, and a second to switch to the new > joint registration routine. For some devices the first step is trivial, > so it's done in one patch. > > Patch 19/21 then retires the old I/O port interface, by removing ioport.c > and friends. > > The final two patches switch the UART and the RTC device over to register > on the MMIO "bus", when running on ARM or arm64. This changes the > addresses to be at 16MB, so they are not in the PCI I/O area anymore. > > Admittedly this goal can be achieved much simpler, by just having the > first three patches, and some more changes and ifdef's in the last two, > but I figured it would be good to clean up the I/O port mess for good. This is a very good idea, I thought more than once as I was working on other things that there really is no reason to differentiate between ioport and mmio emulation. Thanks, Alex > > Please have a look and comment! > > Cheers, > Andre > > Andre Przywara (21): > ioport: Remove ioport__setup_arch() > hw/serial: Use device abstraction for FDT generator function > ioport: Retire .generate_fdt_node functionality > mmio: Extend handling to include ioport emulation > hw/i8042: Clean up data types > hw/i8042: Refactor trap handler > hw/i8042: Switch to new trap handlers > x86/ioport: Refactor trap handlers > x86/ioport: Switch to new trap handlers > hw/rtc: Refactor trap handlers > hw/rtc: Switch to new trap handler > hw/vesa: Switch trap handling to use MMIO handler > hw/serial: Refactor trap handler > hw/serial: Switch to new trap handlers > vfio: Refactor ioport trap handler > vfio: Switch to new ioport trap handlers > virtio: Switch trap handling to use MMIO handler > pci: Switch trap handling to use MMIO handler > Remove ioport specific routines > hw/serial: ARM/arm64: Use MMIO at higher addresses > hw/rtc: ARM/arm64: Use MMIO at higher addresses > > Makefile | 1 - > arm/ioport.c | 5 - > hw/i8042.c | 88 ++++++---------- > hw/rtc.c | 91 ++++++++--------- > hw/serial.c | 166 +++++++++++++++++++----------- > hw/vesa.c | 19 +--- > include/kvm/i8042.h | 1 - > include/kvm/ioport.h | 25 ----- > include/kvm/kvm.h | 42 +++++++- > ioport.c | 235 ------------------------------------------- > mips/kvm.c | 5 - > mmio.c | 59 +++++++++-- > pci.c | 82 +++++---------- > powerpc/ioport.c | 6 -- > vfio/core.c | 50 ++++----- > virtio/pci.c | 42 ++------ > x86/ioport.c | 106 +++++++++---------- > 17 files changed, 385 insertions(+), 638 deletions(-) > delete mode 100644 ioport.c > _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel