From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761067AbZENMXI (ORCPT ); Thu, 14 May 2009 08:23:08 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755223AbZENMWu (ORCPT ); Thu, 14 May 2009 08:22:50 -0400 Received: from mx2.redhat.com ([66.187.237.31]:60783 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752058AbZENMWt (ORCPT ); Thu, 14 May 2009 08:22:49 -0400 Message-ID: <4A0C0D17.2060401@redhat.com> Date: Thu, 14 May 2009 15:22:47 +0300 From: Avi Kivity User-Agent: Thunderbird 2.0.0.21 (X11/20090320) MIME-Version: 1.0 To: Gregory Haskins CC: kvm@vger.kernel.org, viro@ZenIV.linux.org.uk, linux-kernel@vger.kernel.org, davidel@xmailserver.org Subject: Re: [KVM PATCH v7 3/3] kvm: add iofd support References: <20090512181134.26131.10023.stgit@dev.haskins.net> <20090512182701.26131.66801.stgit@dev.haskins.net> <4A0BFC56.9090601@redhat.com> <4A0C084F.3040706@novell.com> In-Reply-To: <4A0C084F.3040706@novell.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Gregory Haskins wrote: >>> +#define KVM_IOFD_FLAG_PIO (1 << 1) >>> + >>> +struct kvm_iofd { >>> + __u64 addr; >>> + __u32 len; >>> + __u32 fd; >>> + __u32 flags; >>> + __u8 pad[12]; >>> +}; >>> + >>> >>> >> Please add a data match capability. virtio uses a write with the data >> containing the queue ID, and we want a separate event for each queue. >> > > How about "u64 cookie" ? > Sure, and a bit in flags to enable it. >>> * kvm trace categories >>> @@ -508,6 +519,7 @@ struct kvm_irqfd { >>> #define KVM_DEASSIGN_DEV_IRQ _IOW(KVMIO, 0x75, struct >>> kvm_assigned_irq) >>> #define KVM_ASSIGN_IRQFD _IOW(KVMIO, 0x76, struct kvm_irqfd) >>> #define KVM_DEASSIGN_IRQFD _IOW(KVMIO, 0x77, __u32) >>> +#define KVM_IOFD _IOW(KVMIO, 0x78, struct kvm_iofd) >>> >>> >> Too general a name. It's not doing IO, just sending out notifications. >> > > Hmm...good point. I was trying to reflect "[MM/P]IO-FD". How about > "IOSIGNALFD" > Okay. >> Why have assign/deassign for irqfd and a single ioctl for iofd? >> > Heh.. irqfd "liked" two because the deassign only needed a u32. iofd > needed more or less the same structure for both so I guess I thought I > would be "slick" and condense the vectors. Will fix so they are > symmetrical. > Yeah. You could have both use just one, or both use two. Not sure which is better. -- error compiling committee.c: too many arguments to function