From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752903Ab1HIJRr (ORCPT ); Tue, 9 Aug 2011 05:17:47 -0400 Received: from smtp.eu.citrix.com ([62.200.22.115]:57608 "EHLO SMTP.EU.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750801Ab1HIJRq (ORCPT ); Tue, 9 Aug 2011 05:17:46 -0400 X-IronPort-AV: E=Sophos;i="4.67,342,1309737600"; d="scan'208";a="7171996" Subject: Re: [Xen-devel] [PATCH 2/3] xen/pv-on-hvm kexec: rebind virqs to existing eventchannel ports From: Ian Campbell To: Olaf Hering CC: "linux-kernel@vger.kernel.org" , "Jeremy Fitzhardinge" , Konrad , "xen-devel@lists.xensource.com" In-Reply-To: <20110804162054.510901329@aepfle.de> References: <20110804162053.723541930@aepfle.de> <20110804162054.510901329@aepfle.de> Content-Type: text/plain; charset="UTF-8" Organization: Citrix Systems, Inc. Date: Tue, 9 Aug 2011 10:17:40 +0100 Message-ID: <1312881460.26263.46.camel@zakaz.uk.xensource.com> MIME-Version: 1.0 X-Mailer: Evolution 2.32.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2011-08-04 at 17:20 +0100, Olaf Hering wrote: > During a kexec boot some virqs such as timer and debugirq were already > registered by the old kernel. The hypervisor will return -EEXISTS from > the new EVTCHNOP_bind_virq request and the BUG in bind_virq_to_irq() > triggers. Catch the -EEXISTS error and loop through all possible ports to find > what port belongs to the virq/cpu combo. Would it be better to proactively just query the status of all event channels early on, like you do in find_virq, and setup the irq info structures as appropriate? Rather than waiting for an -EEXISTS I mean. > > Signed-off-by: Olaf Hering > > --- > drivers/xen/events.c | 40 +++++++++++++++++++++++++++++++++++----- > 1 file changed, 35 insertions(+), 5 deletions(-) > > Index: linux-3.0/drivers/xen/events.c > =================================================================== > --- linux-3.0.orig/drivers/xen/events.c > +++ linux-3.0/drivers/xen/events.c > @@ -877,11 +877,35 @@ static int bind_interdomain_evtchn_to_ir > return err ? : bind_evtchn_to_irq(bind_interdomain.local_port); > } > > +/* BITS_PER_LONG is used in Xen */ > +#define MAX_EVTCHNS (64 * 64) > + > +static int find_virq(unsigned int virq, unsigned int cpu) > +{ > + struct evtchn_status status; > + int port, rc = -ENOENT; > + > + memset(&status, 0, sizeof(status)); > + for (port = 0; port <= MAX_EVTCHNS; port++) { > + status.dom = DOMID_SELF; > + status.port = port; > + rc = HYPERVISOR_event_channel_op(EVTCHNOP_status, &status); > + if (rc < 0) > + continue; > + if (status.status != EVTCHNSTAT_virq) > + continue; > + if (status.u.virq == virq && status.vcpu == cpu) { > + rc = port; > + break; > + } > + } > + return rc; > +} > > int bind_virq_to_irq(unsigned int virq, unsigned int cpu) > { > struct evtchn_bind_virq bind_virq; > - int evtchn, irq; > + int evtchn, irq, ret; > > spin_lock(&irq_mapping_update_lock); > > @@ -897,10 +921,16 @@ int bind_virq_to_irq(unsigned int virq, > > bind_virq.virq = virq; > bind_virq.vcpu = cpu; > - if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq, > - &bind_virq) != 0) > - BUG(); > - evtchn = bind_virq.port; > + ret = HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq, > + &bind_virq); > + if (ret == 0) > + evtchn = bind_virq.port; > + else { > + if (ret == -EEXIST) > + ret = find_virq(virq, cpu); > + BUG_ON(ret < 0); > + evtchn = ret; > + } > > xen_irq_info_virq_init(cpu, irq, evtchn, virq); > > > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xensource.com > http://lists.xensource.com/xen-devel