Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753744AbbHUJaD (ORCPT ); Fri, 21 Aug 2015 05:30:03 -0400 Received: from e06smtp13.uk.ibm.com ([195.75.94.109]:44229 "EHLO e06smtp13.uk.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753685AbbHUJ36 (ORCPT ); Fri, 21 Aug 2015 05:29:58 -0400 X-Helo: d06dlp01.portsmouth.uk.ibm.com X-MailFrom: cornelia.huck@de.ibm.com X-RcptTo: linux-kernel@vger.kernel.org Date: Fri, 21 Aug 2015 11:29:46 +0200 From: Cornelia Huck To: Jason Wang Cc: gleb@kernel.org, pbonzini@redhat.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, "Michael S. Tsirkin" Subject: Re: [PATCH 2/3] kvm: don't register wildcard MMIO EVENTFD on two buses Message-ID: <20150821112946.64ae6f7b.cornelia.huck@de.ibm.com> In-Reply-To: <1440144233-29748-2-git-send-email-jasowang@redhat.com> References: <1440144233-29748-1-git-send-email-jasowang@redhat.com> <1440144233-29748-2-git-send-email-jasowang@redhat.com> Organization: IBM Deutschland Research & Development GmbH Vorsitzende des Aufsichtsrats: Martina Koederitz =?UTF-8?B?R2VzY2jDpGZ0c2bDvGhydW5nOg==?= Dirk Wittkopp Sitz der Gesellschaft: =?UTF-8?B?QsO2Ymxpbmdlbg==?= Registergericht: Amtsgericht Stuttgart, HRB 243294 X-Mailer: Claws Mail 3.8.0 (GTK+ 2.24.10; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 15082109-0013-0000-0000-0000051A49FA Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2373 Lines: 76 On Fri, 21 Aug 2015 16:03:52 +0800 Jason Wang wrote: > diff --git a/virt/kvm/eventfd.c b/virt/kvm/eventfd.c > index 9ff4193..834a409 100644 > --- a/virt/kvm/eventfd.c > +++ b/virt/kvm/eventfd.c > @@ -838,11 +838,6 @@ kvm_assign_ioeventfd(struct kvm *kvm, struct kvm_ioeventfd *args) > > kvm_iodevice_init(&p->dev, &ioeventfd_ops); > > - ret = kvm_io_bus_register_dev(kvm, bus_idx, p->addr, p->length, > - &p->dev); > - if (ret < 0) > - goto unlock_fail; > - > /* When length is ignored, MMIO is also put on a separate bus, for > * faster lookups. You probably want to change this comment as well? > */ > @@ -850,9 +845,15 @@ kvm_assign_ioeventfd(struct kvm *kvm, struct kvm_ioeventfd *args) Unfortunately snipped by diff, but the check here is on !len && !PIO, which only does the desired thing as VIRTIO_CCW always uses len == 8. Should the check be for !len && MMIO instead? > ret = kvm_io_bus_register_dev(kvm, KVM_FAST_MMIO_BUS, > p->addr, 0, &p->dev); > if (ret < 0) > - goto register_fail; > + goto unlock_fail; > + } else { > + ret = kvm_io_bus_register_dev(kvm, bus_idx, p->addr, p->length, > + &p->dev); > + if (ret < 0) > + goto unlock_fail; > } Hm... maybe the following would be more obvious: my_bus = (p->length == 0) && (bus_idx == KVM_MMIO_BUS) ? KVM_FAST_MMIO_BUS : bus_idx; ret = kvm_io_bus_register_dev(kvm, my_bus, p->addr, p->length, &pdev->dev); > > + > kvm->buses[bus_idx]->ioeventfd_count++; > list_add_tail(&p->list, &kvm->ioeventfds); (...) > @@ -900,10 +899,11 @@ kvm_deassign_ioeventfd(struct kvm *kvm, struct kvm_ioeventfd *args) > if (!p->wildcard && p->datamatch != args->datamatch) > continue; > > - kvm_io_bus_unregister_dev(kvm, bus_idx, &p->dev); > if (!p->length) { > kvm_io_bus_unregister_dev(kvm, KVM_FAST_MMIO_BUS, > &p->dev); > + } else { > + kvm_io_bus_unregister_dev(kvm, bus_idx, &p->dev); > } Similar comments here... do you want to check for bus_idx == KVM_MMIO_BUS as well? > kvm->buses[bus_idx]->ioeventfd_count--; > ioeventfd_release(p); -- 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/