From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marcelo Tosatti Subject: Re: [PATCH] kvm guest balloon driver Date: Tue, 8 Jan 2008 14:10:05 -0200 Message-ID: <20080108161005.GA22168@dmt> References: <20080108153356.GA21726@dmt> <478399D5.9030707@codemonkey.ws> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: Marcelo Tosatti , kvm-devel , Avi Kivity , virtualization-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Anthony Liguori Return-path: Content-Disposition: inline In-Reply-To: <478399D5.9030707-rdkfGonbjUSkNkDKm+mE6A@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 On Tue, Jan 08, 2008 at 09:42:13AM -0600, Anthony Liguori wrote: > Marcelo Tosatti wrote: > >Following patch introduces a KVM guest balloon driver. Communication > >to/from the host is performed via virtio. > > I'll address the other comments. > >+ virtballoon.dev = vdev; > >+ init_waitqueue_head(&virtballoon.balloon_wait); > >+ init_waitqueue_head(&virtballoon.rmmod_wait); > >+ atomic_set(&virtballoon.inflight_bufs, 0); > >+ > >+ err = request_irq(pvdev->pci_dev->irq, balloon_irq, IRQF_SHARED, > >+ pvdev->vdev.dev.bus_id, &virtballoon); > >+ if (err) > >+ goto out_free_vq; > > > > Why is it taking over the irq? This is very, very wrong. A virtio > device cannot be dependent on being used on top of the virtio-pci backend. A notification is necessary whenever the host changes the target value in the config space. So right now this notification is sharing the same IRQ as the main PCI device. Do you have any suggestion on how to retrieve the IRQ of the virtio device, or some other notification mechanism? ------------------------------------------------------------------------- Check out the new SourceForge.net Marketplace. It's the best place to buy or sell services for just about anything Open Source. http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace