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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 09042C43613 for ; Mon, 24 Jun 2019 10:00:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DB9B1208E3 for ; Mon, 24 Jun 2019 10:00:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728608AbfFXKAe (ORCPT ); Mon, 24 Jun 2019 06:00:34 -0400 Received: from goliath.siemens.de ([192.35.17.28]:33266 "EHLO goliath.siemens.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728620AbfFXKAb (ORCPT ); Mon, 24 Jun 2019 06:00:31 -0400 Received: from mail2.sbs.de (mail2.sbs.de [192.129.41.66]) by goliath.siemens.de (8.15.2/8.15.2) with ESMTPS id x5OA03Fp014621 (version=TLSv1.2 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 24 Jun 2019 12:00:03 +0200 Received: from [167.87.13.35] ([167.87.13.35]) by mail2.sbs.de (8.15.2/8.15.2) with ESMTP id x5OA01AA023870; Mon, 24 Jun 2019 12:00:02 +0200 To: Thomas Gleixner , Ingo Molnar , Borislav Petkov , x86@kernel.org Cc: Linux Kernel Mailing List From: Jan Kiszka Subject: x86: Spurious vectors not handled robustly Message-ID: Date: Mon, 24 Jun 2019 12:00:00 +0200 User-Agent: Mozilla/5.0 (X11; U; Linux i686 (x86_64); de; rv:1.8.1.12) Gecko/20080226 SUSE/2.0.0.12-1.1 Thunderbird/2.0.0.12 Mnenhy/0.7.5.666 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi all, probably since "x86: Avoid building unused IRQ entry stubs" (2414e021ac8d), the kernel can no longer tell spurious IRQs by the APIC apart from spuriously triggered unused vectors. We've managed to trigger such a cause with the Jailhouse hypervisor (incorrectly injected MANAGED_IRQ_SHUTDOWN_VECTOR), and the result was not only a misreport of the vector number (0xff instead of 0xef - took me a while...), but also stalled interrupts of equal and lower priority because a spurious interrupt is not (and must not be) acknowledged. How to address that best? I would say we should at least have separate entry paths for APIC interrupt vs. vectors, to improve robustness in the faulty case. Jan -- Siemens AG, Corporate Technology, CT RDA IOT SES-DE Corporate Competence Center Embedded Linux