Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759054Ab3DYQt2 (ORCPT ); Thu, 25 Apr 2013 12:49:28 -0400 Received: from smtp.citrix.com ([66.165.176.89]:40541 "EHLO SMTP.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758099Ab3DYQt1 (ORCPT ); Thu, 25 Apr 2013 12:49:27 -0400 X-IronPort-AV: E=Sophos;i="4.87,551,1363132800"; d="scan'208";a="21597311" Date: Thu, 25 Apr 2013 17:48:56 +0100 From: Stefano Stabellini X-X-Sender: sstabellini@kaball.uk.xensource.com To: Ian Campbell CC: Stefano Stabellini , "xen-devel@lists.xensource.com" , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "konrad.wilk@oracle.com" Subject: Re: [PATCH v4 2/7] xen/arm: SMP support In-Reply-To: <1366897221.20256.544.camel@zakaz.uk.xensource.com> Message-ID: References: <1366831695-13214-2-git-send-email-stefano.stabellini@eu.citrix.com> <1366897221.20256.544.camel@zakaz.uk.xensource.com> User-Agent: Alpine 2.02 (DEB 1266 2009-07-14) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3407 Lines: 91 On Thu, 25 Apr 2013, Ian Campbell wrote: > On Wed, 2013-04-24 at 20:28 +0100, Stefano Stabellini wrote: > > Map vcpu_info using VCPUOP_register_vcpu_info on secondary cpus. > > > > Call enable_percpu_irq on every cpu. > > > > Changed in v2: > > - move the percpu variable argument fix to a separate patch; > > - remove unused variable. > > > > Signed-off-by: Stefano Stabellini > > --- > > arch/arm/xen/enlighten.c | 38 +++++++++++++++++++++++++++++++++++++- > > 1 files changed, 37 insertions(+), 1 deletions(-) > > > > diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c > > index 99ce189..94bbf3b 100644 > > --- a/arch/arm/xen/enlighten.c > > +++ b/arch/arm/xen/enlighten.c > > @@ -2,6 +2,7 @@ > > #include > > #include > > #include > > +#include > > #include > > #include > > #include > > @@ -32,6 +33,7 @@ struct shared_info xen_dummy_shared_info; > > struct shared_info *HYPERVISOR_shared_info = (void *)&xen_dummy_shared_info; > > > > DEFINE_PER_CPU(struct vcpu_info *, xen_vcpu); > > +DEFINE_PER_CPU(struct vcpu_info, xen_vcpu_info); > > > /* These are unused until we support booting "pre-ballooned" */ > > unsigned long xen_released_pages; > > @@ -148,6 +150,32 @@ int xen_unmap_domain_mfn_range(struct vm_area_struct *vma, > > } > > EXPORT_SYMBOL_GPL(xen_unmap_domain_mfn_range); > > > > +static int __init xen_secondary_init(unsigned int cpu) > > +{ > > + struct vcpu_register_vcpu_info info; > > + struct vcpu_info *vcpup; > > + int err; > > + > > + if (cpu == 0) > > + return 0; > > + > > + pr_info("Xen: initializing cpu%d\n", cpu); > > + vcpup = &per_cpu(xen_vcpu_info, cpu); > > + > > + info.mfn = __pa(vcpup) >> PAGE_SHIFT; > > + info.offset = offset_in_page(vcpup); > > Do you need to somehow guarantee it's not going to cross a page? Maybe > standard C alignment rules make that the case? That is a good question, I don't think that DEFINE_PER_CPU makes any alignment guarantees (standard C alignment aside). I'll switch to __alloc_percpu that allows me to specify an alignment and has the advantage of being dynamically allocated. > > @@ -216,6 +245,8 @@ static int __init xen_guest_init(void) > > * is required to use VCPUOP_register_vcpu_info to place vcpu info > > * for secondary CPUs as they are brought up. */ > > per_cpu(xen_vcpu, 0) = &HYPERVISOR_shared_info->vcpu_info[0]; > > + for_each_online_cpu(i) > > + xen_secondary_init(i); > > > > gnttab_init(); > > if (!xen_initial_domain()) > [...] > > @@ -244,7 +280,7 @@ static int __init xen_init_events(void) > > return -EINVAL; > > } > > > > - enable_percpu_irq(xen_events_irq, 0); > > + on_each_cpu(xen_percpu_enable_events, NULL, 0); > > It feels like there ought to be some sort of per-cpu bringup callback > which takes care of these dynamically. Maybe that doesn't matter until > we get vcpu hotplug going? I suspect there isn't one, considering that on_each_cpu is also used by kvm_vgic_hyp_init, kvm_timer_hyp_init and others. -- 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/