Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754828AbbLIOdu (ORCPT ); Wed, 9 Dec 2015 09:33:50 -0500 Received: from aserp1040.oracle.com ([141.146.126.69]:27088 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754118AbbLIOdt (ORCPT ); Wed, 9 Dec 2015 09:33:49 -0500 From: Boris Ostrovsky To: tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com Cc: x86@kernel.org, linux-kernel@vger.kernel.org, vkuznets@redhat.com, linux@eikelenboom.it, xen-devel@lists.xenproject.org, Boris Ostrovsky , David Vrabel , stable@vger.kernel.org Subject: [PATCH] x86: Xen PV guests don't have the rtc_cmos platform device Date: Wed, 9 Dec 2015 09:32:49 -0500 Message-Id: <1449671569-4540-1-git-send-email-boris.ostrovsky@oracle.com> X-Mailer: git-send-email 1.8.1.4 X-Source-IP: aserv0022.oracle.com [141.146.126.234] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1948 Lines: 58 Adding the rtc platform device in a Xen PV guests causes an IRQ conflict because these guests do not have a legacy PIC. In a single VCPU Xen PV guest we should have: /proc/interrupts: CPU0 0: 4934 xen-percpu-virq timer0 1: 0 xen-percpu-ipi spinlock0 2: 0 xen-percpu-ipi resched0 3: 0 xen-percpu-ipi callfunc0 4: 0 xen-percpu-virq debug0 5: 0 xen-percpu-ipi callfuncsingle0 6: 0 xen-percpu-ipi irqwork0 7: 321 xen-dyn-event xenbus 8: 90 xen-dyn-event hvc_console ... But hvc_console cannot get its interrupt because it is already in use by rtc0 and the console does not work. genirq: Flags mismatch irq 8. 00000000 (hvc_console) vs. 00000000 (rtc0) So don't add the rtc_cmos device in Xen PV guests. (In fact, don't add it to any paravirt_enabled() guest since lguest is also unable to probe this device) Reported-by: Sander Eikelenboom Signed-off-by: David Vrabel Signed-off-by: Boris Ostrovsky Tested-by: Sander Eikelenboom Cc: stable@vger.kernel.org --- arch/x86/kernel/rtc.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/x86/kernel/rtc.c b/arch/x86/kernel/rtc.c index cd96852..dd4d6d9 100644 --- a/arch/x86/kernel/rtc.c +++ b/arch/x86/kernel/rtc.c @@ -200,6 +200,9 @@ static __init int add_rtc_cmos(void) } #endif + if (paravirt_enabled()) + return -ENODEV; + platform_device_register(&rtc_device); dev_info(&rtc_device.dev, "registered platform RTC device (no PNP device found)\n"); -- 1.8.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/