From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Subject: Re: [RFC 1/4] New virtio bus driver Date: Mon, 9 Jul 2007 13:38:19 +0200 Message-ID: <200707091338.20288.arnd@arndb.de> References: <20070706124200.988637662@arndb.de> <200707091318.48261.arnd@arndb.de> <46921EDF.7080602@qumranet.com> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <46921EDF.7080602@qumranet.com> Content-Disposition: inline List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org To: virtualization@lists.linux-foundation.org List-Id: virtualization@lists.linuxfoundation.org On Monday 09 July 2007, Avi Kivity wrote: > > The problem with hotplugging devices on PCI is that there is not a go= od > > standard for this yet. The best option we have is probably PCI expres= s > > hotplug, but I'm not sure how many legacy operating systems already s= upport > > this. >=20 > This is indeed a problem. =A0Perhaps we should have a virtqueue for=20 > reconfiguration (with a couple of read messages always queued for=20 > host-side changes, and a write message sent when the guest reconfigures= ). Yes, that would be my preferred solution as well. For devices that need reconfiguration capability, one virtqueue for all out-of-band information should be enough, with device specific messages. Why do you think we want to have multiple outstanding read messages? I would guess that a single message is enough, you can always requeue it after one event gets processed. Arnd <><