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.xenproject.org (lists.xenproject.org [192.237.175.120]) (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 05167C433EF for ; Tue, 18 Jan 2022 08:46:00 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.258396.444916 (Exim 4.92) (envelope-from ) id 1n9k7a-0007CN-7n; Tue, 18 Jan 2022 08:45:42 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 258396.444916; Tue, 18 Jan 2022 08:45:42 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1n9k7a-0007CG-4X; Tue, 18 Jan 2022 08:45:42 +0000 Received: by outflank-mailman (input) for mailman id 258396; Tue, 18 Jan 2022 08:45:41 +0000 Received: from se1-gles-sth1-in.inumbo.com ([159.253.27.254] helo=se1-gles-sth1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1n9k7Y-0007C6-Vi for xen-devel@lists.xenproject.org; Tue, 18 Jan 2022 08:45:41 +0000 Received: from mail-lf1-x135.google.com (mail-lf1-x135.google.com [2a00:1450:4864:20::135]) by se1-gles-sth1.inumbo.com (Halon) with ESMTPS id 03690ac8-783b-11ec-9bbc-9dff3e4ee8c5; Tue, 18 Jan 2022 09:45:39 +0100 (CET) Received: by mail-lf1-x135.google.com with SMTP id o15so67646545lfo.11 for ; Tue, 18 Jan 2022 00:45:39 -0800 (PST) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 03690ac8-783b-11ec-9bbc-9dff3e4ee8c5 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=53Y9XNRQIP/ZWA6H6OV0LmYLgUysqj/JBTf1VdkMq1Y=; b=o47fye0Cmq6kklRHHtA/PQU7Bb6F4RizYW+1H8NFSFg0cJyTwyV9UrMHQmXPXLi/l0 imRubE4zJpFhiZhEuQ9XNOLsfylLpSQCz0DqYdjKgAk0Geccl7qjVS3YTCU2v9jra7nz U4YZASFOeSpIIYCzuRJcQbuBsWH5w5sqZXioAN9tuLQnwpVpnFdNf4y5I0L9ev4MXrwm kE4JmsNNpNlxqmG45pBfa29udXdC2WmQrO2L4V7tf8oSdQIwrZsReuDx2HhKT8PMLrmm yT1eaJhsXDDC2d4/9bYyYSduEtsOOrvBcrjdNwVl4EA3439+3rICSo4JLcrBTVYbznUB 74PA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=53Y9XNRQIP/ZWA6H6OV0LmYLgUysqj/JBTf1VdkMq1Y=; b=ZE7PwqX7fQ3SZNvcVHgqPuYIUsdihwN53CIQJMpJAXLw4efyiJyLE8rl8kFJTdMWQq 5VMSYp2Q6ttsmU0RK0dtnZc45JGsv2dCZj0pNN1h0553QOzHRfkqyg0nrL1P/5c8ZP9n VMZsfxRHT2bBCN9MB+Mp8IOEiWrs5QDaP+VyIEqlf1t3B237sKtG353LM8IJS1TEEI/i Qn4Pe6Y4vCbrMzQ7dFUcTX3mbdZIwb7OSCASyp0/auC0HCVZm6PVK4di4R9xiNBrQKKy 5aFdZXjPQiAuNddjrYz4dquSv7k9DvbY6IpFNEDaffqDMyC3N9oen8Xh+cayBxyBC7eN Db6Q== X-Gm-Message-State: AOAM531vZ6iLKtPZgKZZgUeHqx2F6pEM09EpPR6yqPuacE0fCOEshZW0 fxOtOz9nPoWpgA+7sn558LUrV4fExIBV4mdgWKc= X-Google-Smtp-Source: ABdhPJzNpqHtYfFiahZe1gt8fpK95T4/n6x0kndDydXZ84NLnqYp+nuXSIOEJ6Ix0cB/EKVPUc0QGFtRhf8cLCs2GxE= X-Received: by 2002:a05:651c:542:: with SMTP id q2mr1145837ljp.201.1642495539314; Tue, 18 Jan 2022 00:45:39 -0800 (PST) MIME-Version: 1.0 References: <20220117064003.3367188-1-gengdongjiu1@gmail.com> <2a1a0dd5-b8a7-8072-2961-b1fbe9ec746a@xen.org> In-Reply-To: <2a1a0dd5-b8a7-8072-2961-b1fbe9ec746a@xen.org> From: Dongjiu Geng Date: Tue, 18 Jan 2022 16:45:29 +0800 Message-ID: Subject: Re: [PATCH v4] xen/arm: Allow QEMU platform to be built with GICv2 To: Julien Grall Cc: Stefano Stabellini , Volodymyr Babchuk , Bertrand Marquis , xen-devel Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Julien Grall =E4=BA=8E2022=E5=B9=B41=E6=9C=8817=E6=97=A5= =E5=91=A8=E4=B8=80 22:16=E5=86=99=E9=81=93=EF=BC=9A > > Hi, > > On 17/01/2022 10:40, Dongjiu Geng wrote: > > It turns out that QEMU has been supporting GICv2 virtualization since > > v3.1.0. So remove the dependencies on GICv3. > > > Technically, the current form of CONFIG_QEMU allows the same binary to > boot on QEMU with GICv2 or GICv3. > > > If we want to use GICv3, > > we can select the QEMU_LEGACY configuration. > > AFAIK, GICv3 is not a legacy feature... So it feels a bit odd to name it > like that (see more below). Legacy means QEMU platform only supports GICV3, now it can support both GICv2 and GICv3. The scope of support has been expanded Not mean GICv3 is a legacy feature. > > > > > Signed-off-by: Dongjiu Geng > > --- > > xen/arch/arm/platforms/Kconfig | 10 +++++++++- > > 1 file changed, 9 insertions(+), 1 deletion(-) > > > > diff --git a/xen/arch/arm/platforms/Kconfig b/xen/arch/arm/platforms/Kc= onfig > > index c93a6b2756..41e82a42ee 100644 > > --- a/xen/arch/arm/platforms/Kconfig > > +++ b/xen/arch/arm/platforms/Kconfig > > @@ -13,7 +13,15 @@ config ALL_PLAT > > automatically select any of the related drivers. > > > > config QEMU > > - bool "QEMU aarch virt machine support" > > + bool "QEMU aarch virt machine support >=3D v3.1.0" > > This is a bit misleading. A user may select this thinking that this will > select GICv3. However, this will not. > > This also raises the question of what is the default GIC version in QEMU > (i.e. if you don't pass anything on the command line)? If this is GICv3, > then I am afraid that this patch would be a no-go for me. > > Looking at overall discussion, you seem to push the patch only to allow > building a tiny Xen for QEMU and the new vGIC. > > The default Xen (i.e. make defconfig) will also work on QEMU. Given that > the new vGIC is a still in development, I am seriously considering to > say that if you want to try it then you have to use the default > configuration. > > @Dongjiu, is there any reason why you want to use the tiny QEMU config > rather than the default configuration? Hi Julien, thanks for the reply, I do not use the tiny QEMU config. I used the default configuration and selected the platform as QEMU. But QEMU platform only slects GICV3, so I submit this patch to remove the limitation because I want to use VGIC. VGIC can already support GICv2 now. > > @Bertrand, @Stefano, what do you think? > > Cheers, > > -- > Julien Grall