From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752918AbbIOQr1 (ORCPT ); Tue, 15 Sep 2015 12:47:27 -0400 Received: from mx1.redhat.com ([209.132.183.28]:43895 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751979AbbIOQr0 (ORCPT ); Tue, 15 Sep 2015 12:47:26 -0400 Subject: Re: [PATCH V6 6/6] kvm: add fast mmio capabilitiy To: Cornelia Huck References: <1442299319-5253-1-git-send-email-jasowang@redhat.com> <1442299319-5253-7-git-send-email-jasowang@redhat.com> <55F8344B.50300@redhat.com> <20150915181319.097e341c.cornelia.huck@de.ibm.com> <55F8477D.7040803@redhat.com> <20150915184444.6cc6e648.cornelia.huck@de.ibm.com> Cc: Jason Wang , gleb@kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, mst@redhat.com From: Paolo Bonzini Message-ID: <55F84B99.7020903@redhat.com> Date: Tue, 15 Sep 2015 18:47:21 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.2.0 MIME-Version: 1.0 In-Reply-To: <20150915184444.6cc6e648.cornelia.huck@de.ibm.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 15/09/2015 18:44, Cornelia Huck wrote: >> > Can you explain why? If there is any non-zero valid length, "wildcard >> > length" (represented by zero) would also make sense. > What is a wildcard match supposed to mean in this case? The datamatch > field contains the queue index for the device specified in the address > field. The hypercall interface associated with the eventfd always has > device + queue index in its parameters; there is no interface for > "notify device with all its queues". Ah, I see. Because all valid virtio-ccw ioeventfds are datamatch, no valid virtio-ccw ioeventfd is wildcard-length. Paolo