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 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 45A47C48BC3 for ; Mon, 19 Feb 2024 12:34:08 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rc2qA-0008UY-Ip; Mon, 19 Feb 2024 07:33:46 -0500 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 ) id 1rc2q9-0008UH-Ck for qemu-devel@nongnu.org; Mon, 19 Feb 2024 07:33:45 -0500 Received: from mail-ej1-x631.google.com ([2a00:1450:4864:20::631]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1rc2q7-0004dl-Dp for qemu-devel@nongnu.org; Mon, 19 Feb 2024 07:33:45 -0500 Received: by mail-ej1-x631.google.com with SMTP id a640c23a62f3a-a3e82664d53so125727266b.3 for ; Mon, 19 Feb 2024 04:33:43 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1708346022; x=1708950822; darn=nongnu.org; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=S4E0yzAO2ngkn+tDnZ9rriKrakxyWrEzizN7ZdrHINY=; b=TErCjBlWK/bDUkdJ63rXMbU3BFCzqT+YtwIRoAP0xWFCQYmZnLwOsKpgTAIRmYUN+T VbpGejWkRUp1k68Q6QOnpCFMIYjfHnXSuFlRn1Z8d4n+zt6tI6y8W8HR/VVxrW/nD1Si 9Lw5Vml0WCY/vLK45JtekbrHEJo4H5Llc1Dp/W+QWNxo6eJA9kYRjqzaVa35B1gBuqpl OSjWzEZ1KQBwD1rbHChNef3qdwcuXv+gx3055hDeyhkClv3NyLhkMrKQlWPDtjOs3c4h BY6q5xgXQ11TiasTpL5MjFa1bV0G8VBNQCvAWjKZ9hPGAOeSOfkrIfqWEEu+tcYvoH5o zXOg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1708346022; x=1708950822; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=S4E0yzAO2ngkn+tDnZ9rriKrakxyWrEzizN7ZdrHINY=; b=B9KiHf2en0jswt9Ddbb+AFikX3PoZXDd1TU/PGQuT7psgNrIAtqep2dwhNskX1Tnzi jr9XJq35ZNvUfYdnBO7IKHr2/3CakhEVQd/llMREIKL8y0fFn5T84MR5DNUkPlH0x8xJ I0M3XwQPsqwQ7ngi7Iii3rDVjFdr8J1m8erRZELhbBbULU8tsxkXNQ0E5CBZsA+dQv2e dfB76bDz8htBCsW/7aSPI+c0pXl5rFp240RpJHC66Pkw9+n+pI0h+ZiOTcStQH126Elk 2IYTAEzPTyDPIrD5p9buW3jTJvTv8Bw/cmeQgBFBGqh66TjvQHj5hIRvV1cDcwgnU78z r7Pg== X-Gm-Message-State: AOJu0Yx1w8LazkbB4ss8IQ35DkrHqhuiKxQ58IU1XleXtJ/3/icWxxVZ aemrf80xf/1V0toOVAPXr5YVpTZy/beJbY3mA9X+Pzrrt0XkqAkYCsjuTOlVwhw= X-Google-Smtp-Source: AGHT+IEIaylrIhF+CRfrKdhZa5ZKgIDOjz22A/+79B7ak6gyCIon7CfN6oUMPmG/6W/Z2hop7Lqm9g== X-Received: by 2002:a17:906:f1c5:b0:a3e:5d06:be57 with SMTP id gx5-20020a170906f1c500b00a3e5d06be57mr2978095ejb.41.1708346021695; Mon, 19 Feb 2024 04:33:41 -0800 (PST) Received: from [192.168.69.100] ([176.176.181.220]) by smtp.gmail.com with ESMTPSA id s8-20020a170906500800b00a3de4c7bf00sm2903610ejj.79.2024.02.19.04.33.39 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 19 Feb 2024 04:33:41 -0800 (PST) Message-ID: Date: Mon, 19 Feb 2024 13:33:38 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 1/6] hw/arm: Inline sysbus_create_simple(PL110 / PL111) Content-Language: en-US To: BALATON Zoltan Cc: qemu-devel@nongnu.org, =?UTF-8?Q?Daniel_P=2E_Berrang=C3=A9?= , Eduardo Habkost , qemu-arm@nongnu.org, kvm@vger.kernel.org, Peter Maydell , Igor Mitsyanko , "Michael S. Tsirkin" , Marcel Apfelbaum , Paolo Bonzini , Richard Henderson , Markus Armbruster , Manos Pitsidianakis References: <20240216153517.49422-1-philmd@linaro.org> <20240216153517.49422-2-philmd@linaro.org> <2f8ec2e2-c4c7-48c3-9c3d-3e20bc3d6b9b@linaro.org> <00e2b898-3c5f-d19c-fddc-e657306e071f@eik.bme.hu> <2b9ea923-c4f9-4ee4-8ed2-ba9f62c15579@linaro.org> <6b5758d6-f464-2461-f9dd-71d2e15b610a@eik.bme.hu> From: =?UTF-8?Q?Philippe_Mathieu-Daud=C3=A9?= In-Reply-To: <6b5758d6-f464-2461-f9dd-71d2e15b610a@eik.bme.hu> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=2a00:1450:4864:20::631; envelope-from=philmd@linaro.org; helo=mail-ej1-x631.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, 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, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham 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 On 19/2/24 13:00, BALATON Zoltan wrote: > On Mon, 19 Feb 2024, Philippe Mathieu-Daudé wrote: >> On 19/2/24 12:27, BALATON Zoltan wrote: >>> On Mon, 19 Feb 2024, Philippe Mathieu-Daudé wrote: >>>> On 16/2/24 20:54, Philippe Mathieu-Daudé wrote: >>>>> On 16/2/24 18:14, BALATON Zoltan wrote: >>>>>> On Fri, 16 Feb 2024, Philippe Mathieu-Daudé wrote: >>>>>>> We want to set another qdev property (a link) for the pl110 >>>>>>> and pl111 devices, we can not use sysbus_create_simple() which >>>>>>> only passes sysbus base address and IRQs as arguments. Inline >>>>>>> it so we can set the link property in the next commit. >>>>>>> >>>>>>> Signed-off-by: Philippe Mathieu-Daudé >>>>>>> --- >>>>>>> hw/arm/realview.c    |  5 ++++- >>>>>>> hw/arm/versatilepb.c |  6 +++++- >>>>>>> hw/arm/vexpress.c    | 10 ++++++++-- >>>>>>> 3 files changed, 17 insertions(+), 4 deletions(-) >>>>>>> >>>>>>> diff --git a/hw/arm/realview.c b/hw/arm/realview.c >>>>>>> index 9058f5b414..77300e92e5 100644 >>>>>>> --- a/hw/arm/realview.c >>>>>>> +++ b/hw/arm/realview.c >>>>>>> @@ -238,7 +238,10 @@ static void realview_init(MachineState >>>>>>> *machine, >>>>>>>     sysbus_create_simple("pl061", 0x10014000, pic[7]); >>>>>>>     gpio2 = sysbus_create_simple("pl061", 0x10015000, pic[8]); >>>>>>> >>>>>>> -    sysbus_create_simple("pl111", 0x10020000, pic[23]); >>>>>>> +    dev = qdev_new("pl111"); >>>>>>> +    sysbus_realize_and_unref(SYS_BUS_DEVICE(dev), &error_fatal); >>>>>>> +    sysbus_mmio_map(SYS_BUS_DEVICE(dev), 0, 0x10020000); >>>>>>> +    sysbus_connect_irq(SYS_BUS_DEVICE(dev), 0, pic[23]); >>>>>> >>>>>> Not directly related to this patch but this blows up 1 line into 4 >>>>>> just to allow setting a property. Maybe just to keep some >>>>>> simplicity we'd rather need either a sysbus_realize_simple >>>>>> function that takes a sysbus device instead of the name and does >>>>>> not create the device itself or some way to pass properties to >>>>>> sysbus create simple (but the latter may not be easy to do in a >>>>>> generic way so not sure about that). What do you think? >>>>> >>>>> Unfortunately sysbus doesn't scale in heterogeneous setup. >>>> >>>> Regarding the HW modelling API complexity you are pointing at, we'd >>>> like to move from the current imperative programming paradigm to a >>>> declarative one, likely DSL driven. Meanwhile it is being investigated >>>> (as part of "Dynamic Machine"), I'm trying to get the HW APIs right >>> >>> I'm aware of that activity but we're currently still using board code >>> to construct machines and probably will continue to do so for a >>> while. Also because likely not all current machines will be converted >>> to new declarative way so having a convenient API for that is still >>> useful. >>> >>> (As for the language to describe the devices of a machine and their >>> connections declaratively the device tree does just that but dts is >>> not a very user friendly descrtiption language so I haven't brought >>> that up as a possibility. But you may still could get some clues by >>> looking at the problems it had to solve to at least get a >>> requirements for the machine description language.) >>> >>>> for heterogeneous emulation. Current price to pay is a verbose >>>> imperative QDev API, hoping we'll get later a trivial declarative one >>>> (like this single sysbus_create_simple call), where we shouldn't worry >>>> about the order of low level calls, whether to use link or not, etc. >>> >>> Having a detailed low level API does not prevent a more convenient >>> for current use higher level API on top so keeping that around for >>> current machines would allow you to chnage the low level API without >>> having to change all the board codes because you's only need to >>> update the simple high level API. >> >> So what is your suggestion here, add a new complex helper to keep >> a one-line style? >> >> DeviceState *sysbus_create_simple_dma_link(const char *typename, >>                                           hwaddr baseaddr, >>                                           const char *linkname, >>                                           Object *linkobj, >>                                           qemu_irq irq); > > I think just having sysbus_realize_simple that does the same as > sysbus_create_simple minus creating the device would be enough because > then the cases where you need to set properties could still use it after > qdev_new or init and property_set but hide the realize and connecting > the device behind this single call. So you suggest splitting sysbus_create_simple() as sysbus_create_simple() + sysbus_realize_simple(), so we can set properties between the 2 calls? IOW extract qdev_new() from sysbus_create_varargs() and rename it as sysbus_realize_simple()? So we need a massive refactoring of: - dev = sysbus_create_simple(typename, addr, irq); + dev = qdev_new(typename); + // optionally set properties + sysbus_realize_simple(dev, addr, irq); - dev = sysbus_create_varargs(typename, addr, irqA, irqB, ...); + dev = qdev_new(typename); + // optionally set properties + sysbus_realize_varargs(dev, addr, irqA, irqB, ...); I'm not sure it is worth it because we want to move away from sysbus, merging the non-sysbus specific API to qdev (like indexed memory regions and IRQs to named ones). >> I wonder why this is that important since you never modified >> any of the files changed by this series: > > For new people trying to contribute to QEMU QDev is overwhelming so > having some way to need less of it to do simple things would help them > to get started. > > Regards, > BALATON Zoltan