Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755244AbbLDQOZ (ORCPT ); Fri, 4 Dec 2015 11:14:25 -0500 Received: from userp1040.oracle.com ([156.151.31.81]:19465 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753617AbbLDQOW (ORCPT ); Fri, 4 Dec 2015 11:14:22 -0500 Subject: Re: [Xen-devel] [PATCHv1] x86: rtc_cmos platform device requires legacy irqs To: Vitaly Kuznetsov References: <1449139404-25101-1-git-send-email-david.vrabel@citrix.com> <56619DCE.3050900@citrix.com> <5661B033.10503@citrix.com> <5661B2AD.3030808@oracle.com> <87io4e5hz4.fsf@vitty.brq.redhat.com> Cc: David Vrabel , x86@kernel.org, linux-kernel@vger.kernel.org, Ingo Molnar , "H. Peter Anvin" , xen-devel@lists.xenproject.org, Thomas Gleixner From: Boris Ostrovsky Message-ID: <5661BBD1.2010507@oracle.com> Date: Fri, 4 Dec 2015 11:14:09 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.1.0 MIME-Version: 1.0 In-Reply-To: <87io4e5hz4.fsf@vitty.brq.redhat.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-Source-IP: userv0021.oracle.com [156.151.31.71] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1762 Lines: 47 On 12/04/2015 10:52 AM, Vitaly Kuznetsov wrote: > Boris Ostrovsky writes: > >> On 12/04/2015 10:24 AM, David Vrabel wrote: >>> On 04/12/15 14:06, David Vrabel wrote: >>>> On 03/12/15 10:43, David Vrabel wrote: >>>>> Adding the rtc platform device when there are no legacy irqs (no >>>>> legacy PIC) causes a conflict with other devices that end up using the >>>>> same irq number. >>>> An alternative is to remove the rtc_cmos platform device in Xen PV >>>> guests. >>>> >>>> Any preference on how this regression should be fixed? >>>> >>>> David >>>> >>>> 8<-------------------------- >>>> x86: Xen PV guests don't have the rtc_cmos platform device >>>> >>> [...] >>>> --- 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 (xen_pv_domain()) >>>> + return -ENODEV; >>>> + >>> Note there's a missing include that breaks !XEN builds. >> We could also use paravirt_enable() here which will probably cover >> HVMlite case as well. (Until we start turning on and off various >> HVMlite features). > Would it make sense to create a new abstraction, e.g. 'rtc_available' in > struct hypervisor_x86? We could do this but since this fine-grained feature enabling is still way off it may be worth waiting until we actually get to this. Besides, it would probably be something like if (paravirt_enabled() && !rtc_available) so for now having just the first term should suffice. -boris -- 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/