From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: [PATCH v3 3/6] vbus: add a "vbus-proxy" bus model for vbus_driver objects Date: Tue, 18 Aug 2009 13:09:45 +0300 Message-ID: <20090818100945.GD13878@redhat.com> References: <20090814154125.26116.70709.stgit@dev.haskins.net> <20090814154308.26116.46980.stgit@dev.haskins.net> <20090815103243.GA26749@elte.hu> <4A8954F0.3040402@gmail.com> <20090817142506.GB3602@elte.hu> <4A8971A8.2040102@gmail.com> <20090817150844.GA3307@elte.hu> <4A89B08A.4010103@gmail.com> <20090818095313.GC13878@redhat.com> <4A8A7BB9.2020906@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Gregory Haskins , Ingo Molnar , Gregory Haskins , kvm@vger.kernel.org, alacrityvm-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, netdev@vger.kernel.org To: Avi Kivity Return-path: Content-Disposition: inline In-Reply-To: <4A8A7BB9.2020906@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Tue, Aug 18, 2009 at 01:00:25PM +0300, Avi Kivity wrote: > On 08/18/2009 12:53 PM, Michael S. Tsirkin wrote: >> I'm not hung up on PCI, myself. An idea that might help you get Avi >> on-board: do setup in userspace, over PCI. Negotiate hypercall support >> (e.g. with a PCI capability) and then switch to that for fastpath. Hmm? >> > > Hypercalls don't nest well. When a nested guest issues a hypercall, you > have to assume it is destined to the enclosing guest, so you can't > assign a hypercall-capable device to a nested guest. > > mmio and pio don't have this problem since the host can use the address > to locate the destination. So userspace could map hypercall to address during setup and tell the host kernel? > -- > error compiling committee.c: too many arguments to function