From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark McLoughlin Subject: Re: [PATCH 1/1] kvm: qemu: Add VIRTIO_F_NOTIFY_ON_EMPTY Date: Wed, 18 Jun 2008 18:21:21 +0100 Message-ID: <1213809681.19629.2.camel@muff> References: <1213362983-17025-1-git-send-email-markmc@redhat.com> <48590E44.2030202@qumranet.com> Reply-To: Mark McLoughlin Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: kvm-devel To: Avi Kivity Return-path: Received: from mx1.redhat.com ([66.187.233.31]:40033 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751803AbYFRRV0 (ORCPT ); Wed, 18 Jun 2008 13:21:26 -0400 In-Reply-To: <48590E44.2030202@qumranet.com> Sender: kvm-owner@vger.kernel.org List-ID: On Wed, 2008-06-18 at 06:31 -0700, Avi Kivity wrote: > Mark McLoughlin wrote: > > Set the VIRTIO_F_NOTIFY_ON_EMPTY feature bit so the > > guest can rely on us notifying them when the queue > > is empty. > > > > Also, only notify when the available queue is empty > > *and* when we've finished with all the buffers we > > had detached. Right now, when the queue is empty, > > we notify the guest for every used buffer. > > > > This is a bit inflexible. I would prefer a mechanism where the guest > tells us at what queue index it would like the notification, like Xen. > If it wants it on queue empty, it just sets the index appropriately. > > Or is the usage in the drivers already upstream and I have no choice > about applying this? Something like that :-) commits: http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=b4f68be6c5d507afdcd74f5be3df0b1209cda503 http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=363f15149cfba67d29f1e6a6103dda079f27f3fa http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=20887611523e749d99cc7d64ff6c97d27529fbae Cheers, Mark.