Hi,
I started porting the NetBSD virtio drivers from NetBSD to DragonFly.
I'm currently working through the virtio-net attach routine and setting
up the appropriate infrastructure.
I believe I'm creating the drivers incorrectly. To set some context, I'm
developing with a networking virtio device on VirtualBox. When I start
the dragonfly VM, there is a single PCI device that shows up, which is a
virtio device:
00:08.0 Ethernet controller: Qumranet, Inc. Virtio network device
The way I currently have the drivers structured is there a virtiobus
driver (pci child), which has all the infrastructure routines, and then
there are child drivers: virtio-net, virtio-blk, etc, which will end up
calling routines in the virtiobus driver to setup dma, etc.
When I load the virtiobus driver, probe and attach are successfull for
that PCI device. Then when I load the virtio-net driver, probe isn't
called because that device has already been satisfied. In order to get
around that, I implemented the identify() routine in the virtio-net
driver, which is called when I load the driver. If the device is of our
type (networking, block, etc), then we add a new child device to the
parent (virtiobus) of the appropriate type and force a probe. The pseudo
code is below.
virtiobus.c:
virtio_probe(){
if (is virtio device){ /*pci_get_device*()*/
return 0;
}
}
virtio-net.c:
netvirtio_identify(){
if (is a virtio network subdevice){ /*pci_read_config(subdevice)*/
dev = device_add_child();
bus_generic_probe(dev);
}
}
netvirtio_probe(){
return 0; /*only called if identify succeeds*/
}
netvirtio_attach(){
set stuff up;
}
I'm not sure if this was the right way to go about it, so any
tips/suggestions are appreciated.
Tim
The code I'm currently working on is at:
http://gitorious.org/virtio-drivers