[Qemu-devel] Why one virtio-pci device has two different DeviceState?

[Jintack Lim]

Hi,

I was wondering why one virtio-pci device has two different
DeviceState? - one directly from VirtIOPCIProxy and the other from
VirtIO<dev type> such as VirtIONet. As an example, they are denoted as
qdev and vdev respectively in virtio_net_pci_realize().

I thought that just one DeviceState is enough for any device in QEMU.
Maybe I'm missing something fundamental here.

*Just* for people who wonder why I'm asking this question, I'd like to
find a device in the list of SaveStateEntry on a MMIO operation to a
PCI device. For virtio devices, I only have qdev information in the
MMIO handler while I need to have vdev information to find the virtio
device in the SaveStateEntry list. I can possibly do this by
converting qdev to vdev knowing this is a virtio device as in
virtio_net_pci_realize(), but I'd like to find a way to do it without
knowing the device is a virtio device.

Thanks,
Jintack