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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2AE04C6FD19 for ; Mon, 13 Mar 2023 11:20:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229782AbjCMLUC (ORCPT ); Mon, 13 Mar 2023 07:20:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39834 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229568AbjCMLTn (ORCPT ); Mon, 13 Mar 2023 07:19:43 -0400 Received: from mail.skyhub.de (mail.skyhub.de [IPv6:2a01:4f8:190:11c2::b:1457]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CF0A21CAD0 for ; Mon, 13 Mar 2023 04:19:42 -0700 (PDT) Received: from zn.tnic (p5de8e9fe.dip0.t-ipconnect.de [93.232.233.254]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id 1DA781EC0622; Mon, 13 Mar 2023 12:14:26 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1678706066; 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:in-reply-to:in-reply-to: references:references; bh=q4K/luGIvNlfTYgfX/OXMxPl2jFxTBSD3xwYqJRQPEY=; b=CipRRVa/2qmn3LcWD77C8VUGaZquEytQi1frTALmD5bexg9E4SDyHPGr4DFP/405GeMfNt 91ikntoQQWDaF/x9KMzorsBapf0JESpdRo7AgrqRbRJosh0KF09q67LKDMUeYDdORpihDw 6TyhL9MQ5SmX6qfucskTKG2Uog0XYgc= Date: Mon, 13 Mar 2023 12:14:25 +0100 From: Borislav Petkov To: Saurabh Singh Sengar Cc: Saurabh Sengar , "tglx@linutronix.de" , "mingo@redhat.com" , "dave.hansen@linux.intel.com" , "x86@kernel.org" , "hpa@zytor.com" , "johan+linaro@kernel.org" , "isaku.yamahata@intel.com" , "Michael Kelley (LINUX)" , "linux-kernel@vger.kernel.org" , "rahul.tanwar@linux.intel.com" , "andriy.shevchenko@intel.com" Subject: Re: [EXTERNAL] Re: [PATCH] x86/ioapic: Don't return 0 as valid virq Message-ID: <20230313111425.GDZA8Fkar9Z9BzSImD@fat_crate.local> References: <1677785686-2152-1-git-send-email-ssengar@linux.microsoft.com> <20230312204019.GBZA44s28AOAfAcRuy@fat_crate.local> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Mar 13, 2023 at 03:29:32AM +0000, Saurabh Singh Sengar wrote: > To be specific in our system which is a guest VM we don't need IO-APIC and hence > there is no device tree node for it. It is observed that we get irq 0 assigned to PCI-MSI. This should be added to your commit message: what guest VM is that and why should the kernel support it. Why doesn't it need an IO-APIC and why does the current code need to be changed just for your guest VM? What else needs to be changed so that your VM works? Where is that VM's documentation and why can't that VM be fixed *not* to need kernel changes? IOW, why can't that VM emulate an IO-APIC like the others do... -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette