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=-5.8 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,URIBL_BLOCKED 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 0B70BC4360C for ; Thu, 18 Mar 2021 10:10:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E664264F6A for ; Thu, 18 Mar 2021 10:10:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230166AbhCRKKa (ORCPT ); Thu, 18 Mar 2021 06:10:30 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:56562 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230101AbhCRKKJ (ORCPT ); Thu, 18 Mar 2021 06:10:09 -0400 From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1616062207; 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: in-reply-to:in-reply-to:references:references; bh=YV79GQE7RAvEFxHJLf8jtJW4XGj4ZQ7NMj/seY0rDi0=; b=2N2x7NqRIu5Nh3AkQJSt8Q+r7uXXEaeJ1hpTF/07Y4iKum0BYLNTp1CuF7cmddSyXk+qN2 5WSc6ACHsHDtdqzBSGC7aXoKPxrryxx23JTyvROF4CW/Fuxw60S3XDt9g3QFefeWIbNo+K h/TJeRErl7XoKWvyaqF+jvIHbZ/ux1gEt/1tuKitNSlqlqoIRXANy5ma0sx60X6OARp19g UJIQ0br3jHRp/CUDYjdRbny6t3vDTHBUeB8NF4dqVZi/g1iqtFV2FvP+ESwcpzg6REGLKe HqlKOdOtQHpv1o7TFa9RqlrcSke5VyEWsg66N4T6yjbzRKvFKylPvRC/6TxiYg== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1616062207; 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: in-reply-to:in-reply-to:references:references; bh=YV79GQE7RAvEFxHJLf8jtJW4XGj4ZQ7NMj/seY0rDi0=; b=NKskUvh7mixZ4pjDcTeS09Wve00Vwpr6/08hL/WmIf9ZNMcjuc+F+ek9bsbQj36qQQs8JW f1ESXZq71kadd5AQ== To: Vitaly Kuznetsov , x86@kernel.org Cc: Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , linux-kernel@vger.kernel.org Subject: Re: [PATCH RFC 1/2] x86/apic: Do not make an exception for PIC_CASCADE_IR when marking legacy irqs in irq_matrix In-Reply-To: <87blbg7tlo.fsf@vitty.brq.redhat.com> References: <20210219113101.967508-1-vkuznets@redhat.com> <20210219113101.967508-2-vkuznets@redhat.com> <87im5py1ty.fsf@nanos.tec.linutronix.de> <87blbg7tlo.fsf@vitty.brq.redhat.com> Date: Thu, 18 Mar 2021 11:10:07 +0100 Message-ID: <87tup8wz5s.fsf@nanos.tec.linutronix.de> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Mar 18 2021 at 09:29, Vitaly Kuznetsov wrote: > Thomas Gleixner writes: >> Out of paranoia I'd rather ignore that IO/APIC pin completely if it >> claims to be IRQ2. I assume there is no device connected to it at all, >> right? > > The original issue was observed on Amazon's r5d.xlarge instance > type. Your assumption seems to be correct, I don't see any device on > IRQ2. > >> >> Can you please provide a dmesg with apic=verbose on the command line? >> > > Here you go, attached. > [ 0.931305] init IO_APIC IRQs > [ 0.931312] IOAPIC[0]: Preconfigured routing entry (0-0 -> IRQ 0 Level:0 ActiveLow:0) > [ 0.931316] IOAPIC[0]: Preconfigured routing entry (0-1 -> IRQ 1 Level:0 ActiveLow:0) There you go: > [ 0.931320] IOAPIC[0]: Preconfigured routing entry (0-2 -> IRQ 2 Level:0 ActiveLow:0) Yet another virtualization feature :) Thanks, tglx