Re: [Qemu-devel] [PATCH] virtio: make bindings typesafe

[Michael S. Tsirkin]

On Mon, Dec 17, 2012 at 06:55:46PM +0100, Andreas Färber wrote:
> Am 17.12.2012 16:45, schrieb Michael S. Tsirkin:
> > diff --git a/hw/virtio-pci.c b/hw/virtio-pci.c
> > index 3ea4140..63ae888 100644
> > --- a/hw/virtio-pci.c
> > +++ b/hw/virtio-pci.c
> > @@ -98,34 +98,34 @@ bool virtio_is_big_endian(void);
> >  
> >  /* virtio device */
> >  
> > -static void virtio_pci_notify(void *opaque, uint16_t vector)
> > +static void virtio_pci_notify(DeviceState *d, uint16_t vector)
> >  {
> > -    VirtIOPCIProxy *proxy = opaque;
> > +    VirtIOPCIProxy *proxy = container_of(d, VirtIOPCIProxy, pci_dev.qdev);
> 
> Nack. This is going the wrong direction QOM-wise and you among all
> others know that from PCI host bridges!
> 
> A core issue being addressed here is that virtio devices are modelled
> neither in the regular qdev way nor the QOM way.

No, the core issue is unsafe void * use.

> They don't inherit
> correctly and use their own set of common-init functions - one side
> effect of Fred's series was to make them first-class QOM citizens. QOM
> like qdev doesn't support multi-inheritence, so the discussed approach
> Fred is trying to implement is to have both a VirtioDevice as base class
> for Virtio{Block,...}Device and PCIDevice/SysBusDevice/... as base class
> for a virtio bridge device with a virtio-bus, on which only virtio is
> spoken and pure VirtioDevices can sit (which as you say have device IDs
> but not all PCI properties).
> What remained under discussion AFAIU was how to expose this modelling
> construct to the user - Peter aiming to expose this to the user and me
> proposing to hide this (for PCI) as an internal implementation detail.
> 
> Whether DeviceState or a new VirtioDevice or something else is being
> used in the API is a different issue that I don't really mind.
> 
> Andreas

Me neither just get rid of void*

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