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 C0030CF9C6B for ; Tue, 24 Sep 2024 15:10:22 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.803044.1213438 (Exim 4.92) (envelope-from ) id 1st7B0-0007k1-78; Tue, 24 Sep 2024 15:10:06 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 803044.1213438; Tue, 24 Sep 2024 15:10:06 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1st7B0-0007jW-4L; Tue, 24 Sep 2024 15:10:06 +0000 Received: by outflank-mailman (input) for mailman id 803044; Tue, 24 Sep 2024 15:10:04 +0000 Received: from se1-gles-flk1-in.inumbo.com ([94.247.172.50] helo=se1-gles-flk1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1st7Ay-0007Se-Qr for xen-devel@lists.xenproject.org; Tue, 24 Sep 2024 15:10:04 +0000 Received: from mail-ed1-x52d.google.com (mail-ed1-x52d.google.com [2a00:1450:4864:20::52d]) by se1-gles-flk1.inumbo.com (Halon) with ESMTPS id 12c2e260-7a87-11ef-99a2-01e77a169b0f; Tue, 24 Sep 2024 17:10:02 +0200 (CEST) Received: by mail-ed1-x52d.google.com with SMTP id 4fb4d7f45d1cf-5c40942358eso9449076a12.1 for ; Tue, 24 Sep 2024 08:10:02 -0700 (PDT) Received: from localhost ([213.195.124.163]) by smtp.gmail.com with ESMTPSA id 4fb4d7f45d1cf-5c5cf49d7ebsm834372a12.45.2024.09.24.08.10.01 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 24 Sep 2024 08:10:01 -0700 (PDT) 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: 12c2e260-7a87-11ef-99a2-01e77a169b0f DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=citrix.com; s=google; t=1727190602; x=1727795402; darn=lists.xenproject.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=byUl82INZlv612W6FxDlVPwsOPRJbIrXPRVbK26XlZg=; b=T8UCokUwLfLG+HxEZocwmNv0UROYW79zHZ0CXVMHheXN+bCYE4vr2kcAx3W18uy9Rm 0G6DciZHunVrf8se5UBYY9Fss+4zIG7y4/PpEV/s49b5n3i1T1dhuEIHu8xKCDfjKqZ0 mvOR02f1orHXcJ1gLNkRkrLj6yqjonkseKHMI= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1727190602; x=1727795402; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=byUl82INZlv612W6FxDlVPwsOPRJbIrXPRVbK26XlZg=; b=AJF+dWvYjfJ1p/TOKNpp0T3KiuwXC5DsY6OX8Sw7bKzsNTW20S4KM4+h2F9c0TMrt6 Bx1yokWzsjcUDQuGeMxz3H43UjFNE4ekQeWP9UQvh9pufaa5JR8ihHK6hkK4wUDmDPhi FX/zGXMwljExG9xE64GwTQtVnykv1g53zvhGyOGrgCLf/0zlefJVMDH+ukHduJfZ93Nx QS7eBfFLjI+3XJggPsbHSl/IF+5ofhPnZwnO9ycxS0BgVF5XnqvhAZC7QSs7OrAZYnps NCZ6U4za2UAK5AySEtAlSb7UEDmnGGIWp2ubgVSi6yBOBqdxK+qZRdQCsPgbEnoDYen/ voqg== X-Gm-Message-State: AOJu0Yw4sK8XZppj7pht0aOT2nmfHve8iMMgd8neZ0R1t41KfmGUr0WK 5cSu+qtGhl+ODs3Ha8D9c9MODrVvvLeJ1Q8y2b23Yh/Pku5lEdfRa5Hh/xulpXk= X-Google-Smtp-Source: AGHT+IHp/g1lzam4D7tPVKmhC6AfBxI5VmXy/mKZ/BdEEhmrNnZB6WlYJ7g/5GVlJJiF/NTukbHG1w== X-Received: by 2002:a05:6402:3509:b0:5c5:cb7f:e56a with SMTP id 4fb4d7f45d1cf-5c5cdfa0523mr3670130a12.1.1727190601999; Tue, 24 Sep 2024 08:10:01 -0700 (PDT) Date: Tue, 24 Sep 2024 17:10:00 +0200 From: Roger Pau =?utf-8?B?TW9ubsOp?= To: Matthew Barnes Cc: xen-devel@lists.xenproject.org, Oleksii Kurochko , Community Manager , Andrew Cooper , Jan Beulich , Julien Grall , Stefano Stabellini Subject: Re: [PATCH] x86/APIC: Remove x2APIC pure cluster mode Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: On Mon, Sep 23, 2024 at 03:35:59PM +0100, Matthew Barnes wrote: > With the introduction of mixed x2APIC mode (using cluster addressing for > IPIs and physical for external interrupts) the use of pure cluster mode > doesn't have any benefit. > > Remove the mode itself, leaving only the code required for logical > addressing when sending IPIs. > > Implements: https://gitlab.com/xen-project/xen/-/issues/189 There's at least one extra bit which I would also like to see removed, either in this patch, or as following patch. In struct arch_irq_desc we have 3 cpumasks: cpu_mask, old_cpu_mask and pending_mask. After dropping cluster mode for external interrupts, those fields could become integers AFACT, as now interrupts can only target a single CPU opposed to a logical CPU set. Thanks, Roger.