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=-3.9 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no 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 E7A4BC433E4 for ; Tue, 25 Aug 2020 07:57:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C50A52071E for ; Tue, 25 Aug 2020 07:57:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="JIpR4o0Q"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="UFHNoPg/" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726090AbgHYH5s (ORCPT ); Tue, 25 Aug 2020 03:57:48 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:47740 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725379AbgHYH5q (ORCPT ); Tue, 25 Aug 2020 03:57:46 -0400 From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1598342264; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=z7XEOONAx/Y/ZiGBa138zNdJ2aL0ZkJolLF35mYWdkk=; b=JIpR4o0QGi7kK727LCmqEP1DulpXQaBIgflkZBLs5t7Lz8BkKPnpuEKumBjEIUv4Qu2fG/ Oir+lSuIqPfxIOiBFQCY78M6YxK5B+THOxc0icLjtAE5JJUVAEoLFxVLAg3uxDsMB1SGXX XnaeD4Z6L/kPkUhTl+94PS6Ks0d2HjckxWbTB9b++Lqlou5zbvd+xX/Hopw1vkn5tYovdo HLgyn2z6ttiQeTALU45iDOFAu5axIGbm6lbmj8cbkv/CZonC9AGBAL/usvMWV2QkosoUW5 3RNUmC/gOSqY1Bc8xh5ArbnCykaJkYqCjP/+V1YJalXwg1JSBYvSGRteI38PbA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1598342264; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=z7XEOONAx/Y/ZiGBa138zNdJ2aL0ZkJolLF35mYWdkk=; b=UFHNoPg/zXQ+Xg2Pv56inRA93Orb7eMVMpZPw2ESh1dxXdBikqTGQn7J7IK19znmQQ8GAl YbijH/OnOMKVGqAA== To: =?utf-8?B?SsO8cmdlbiBHcm/Dnw==?= , LKML Cc: x86@kernel.org, linux-pci@vger.kernel.org, xen-devel@lists.xenproject.org, Joerg Roedel , iommu@lists.linux-foundation.org, linux-hyperv@vger.kernel.org, Haiyang Zhang , Jon Derrick , Lu Baolu , Wei Liu , "K. Y. Srinivasan" , Stephen Hemminger , Steve Wahl , Dimitri Sivanich , Russ Anderson , Bjorn Helgaas , Lorenzo Pieralisi , Konrad Rzeszutek Wilk , Boris Ostrovsky , Stefano Stabellini , Marc Zyngier , Greg Kroah-Hartman , "Rafael J. Wysocki" , Megha Dey , Jason Gunthorpe , Dave Jiang , Alex Williamson , Jacob Pan , Baolu Lu , Kevin Tian , Dan Williams Subject: Re: [patch RFC 26/38] x86/xen: Wrap XEN MSI management into irqdomain In-Reply-To: <8860c7bc-67ab-ce64-0340-1458d2483a39@suse.com> References: <20200821002424.119492231@linutronix.de> <20200821002947.868727656@linutronix.de> <8860c7bc-67ab-ce64-0340-1458d2483a39@suse.com> Date: Tue, 25 Aug 2020 09:57:44 +0200 Message-ID: <87r1rv5f9j.fsf@nanos.tec.linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Mon, Aug 24 2020 at 08:21, J=C3=BCrgen Gro=C3=9F wrote: > On 21.08.20 02:24, Thomas Gleixner wrote: > > Looking into https://www.kernel.org/doc/Documentation/IRQ-domain.txt (is > this still valid?) It's halfways correct. Emphasis on halfways. > I believe Xen should be able to use the "No Map" approach, as Xen only > ever uses software IRQs (at least those are the only ones visible to > any driver). The (virtualized) hardware interrupts are Xen events > after all. > > So maybe morphing Xen into supporting irqdomains in a sane way isn't > that complicated. Maybe I'm missing the main complexities, though. The wrapper domain I did is pretty much that, but with the extra functionality required by hierarchical irq domains. So, yes it's functionally correct, but it's only utilizing the alloc/free interface and not any of the other mechanisms provided by irqdomains. The latter should make the overall code simpler but that obviously needs some thought. Thanks, tglx