From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH 2/6] virtio_config Date: Thu, 20 Sep 2007 14:55:35 +0200 Message-ID: <46F26DC7.9040001@qumranet.com> References: <1190289808.7262.223.camel@localhost.localdomain> <1190290140.7262.228.camel@localhost.localdomain> <1190290369.7262.231.camel@localhost.localdomain> <46F26958.4080102@qumranet.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: kvm-devel , lguest , virtualization To: Rusty Russell Return-path: In-Reply-To: <46F26958.4080102-atKUWr5tajBWk0Htik3J/w@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Errors-To: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: kvm.vger.kernel.org Avi Kivity wrote: > Rusty Russell wrote: >> Previous versions of virtio didn't commonalize probing. For every >> driver, every virtio implementation (KVM, lguest, etc) needed an >> in-kernel stub to join their bus to the probe code. >> >> To solve this, we introduce a "virtio_config" mechanism, which is >> simply a set of [u8 type][u8 len][...data...] fields for each device. >> Some convenient wrapper functions make this fairly easy for drivers to >> unpack their configuration data themselves. >> >> This configuration data could be PCI config space, or an unrelated bus >> (eg. lguest) or manufactured by the kernel itself. It's designed to >> be extensible: fields get marked as the device reads them so a host >> supporting some future extension can tell if the guest driver >> understood it. This also applies to bitfields: the guest explicitly >> acks the bits it understands. >> >> There's also a simple status bitmask useful for low-level host >> analysis of what the guest is doing with the device. >> >> > > Lovely. > A side effect of this is that Xen drivers can no longer use virtio. -- error compiling committee.c: too many arguments to function ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2005. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/