Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755807Ab2HFKi0 (ORCPT ); Mon, 6 Aug 2012 06:38:26 -0400 Received: from mx1.redhat.com ([209.132.183.28]:8945 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754475Ab2HFKiZ (ORCPT ); Mon, 6 Aug 2012 06:38:25 -0400 Message-ID: <501F9E99.9010109@redhat.com> Date: Mon, 06 Aug 2012 13:38:17 +0300 From: Avi Kivity User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:14.0) Gecko/20120717 Thunderbird/14.0 MIME-Version: 1.0 To: Alex Williamson CC: mst@redhat.com, gleb@redhat.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, jan.kiszka@siemens.com Subject: Re: [PATCH v7 2/2] kvm: KVM_EOIFD, an eventfd for EOIs References: <20120724203628.21081.56884.stgit@bling.home> <20120724204320.21081.32333.stgit@bling.home> <501F99A8.9050006@redhat.com> In-Reply-To: <501F99A8.9050006@redhat.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1612 Lines: 39 On 08/06/2012 01:17 PM, Avi Kivity wrote: > >> >> +4.77 KVM_EOIFD >> + >> +Capability: KVM_CAP_EOIFD >> +Architectures: x86 >> +Type: vm ioctl >> +Parameters: struct kvm_eoifd (in) >> +Returns: 0 on success, < 0 on error >> + >> +KVM_EOIFD allows userspace to receive interrupt EOI notification >> +through an eventfd. kvm_eoifd.fd specifies the eventfd used for >> +notification. KVM_EOIFD_FLAG_DEASSIGN is used to de-assign an eoifd >> +once assigned. KVM_EOIFD also requires additional bits set in >> +kvm_eoifd.flags to bind to the proper interrupt line. The >> +KVM_EOIFD_FLAG_LEVEL_IRQFD indicates that kvm_eoifd.key is provided >> +and is a key from a level triggered interrupt (configured from >> +KVM_IRQFD using KVM_IRQFD_FLAG_LEVEL). The EOI notification is bound >> +to the same GSI and irqchip input as the irqfd. Both kvm_eoifd.key >> +and KVM_EOIFD_FLAG_LEVEL_IRQFD must be specified on assignment and >> +de-assignment of KVM_EOIFD. A level irqfd may only be bound to a >> +single eoifd. KVM_CAP_EOIFD_LEVEL_IRQFD indicates support of >> +KVM_EOIFD_FLAG_LEVEL_IRQFD. > > Why do we need to couple eoifd and irqfd? Oh, it's to auto-deassert the line. Regarding the implementation, instead of a linked list, would an array of counters parallel to the bitmap make it simpler? -- error compiling committee.c: too many arguments to function -- 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/