Why not do like VMware and emulate a nic on your host machine and then emulate
a nic on the guest os and have the guest os's nic connect to the host machine's
nic as though there were a real network there
Colin Davidson wrote:
> As the subject is coming round to peripherals, and I'm just compeleting an
> NDIS NIC
> driver (windows MAC driver), I thought I'd add my 2c worth.
>
> Having 2 (or more) OSs accessing a network card at the same time, totally
> ignorant
> of each other, is somewhat undesirable (virtually guarantees that networking
> won't
> work for either OS). So, what to do... For windows as the guest, one
> approach would
> be to create a standard NDIS driver and punt the actual operation to the
> host. This
> would be easiest if the Windows networking was TCP/IP based. This is the
> usual case
> anyway. All IP traffic could be punted to the host OS, leaving only a few
> oddballs
> (like DHCP and ARP) that may have to be directly emulated. NIC addresses
> could be
> a problem for DHCP and ARP, but I'm sure we can work around it somehow - by
> setting
> the adapter into promicuous mode, if nothing else.
>
> This would involve spoofing the PCI bus, so that the windows guest thought
> it had
> a suitable NIC to play with, figuring some mechanism to pass requests to the
> host
> to the guest, writing a guest handler to redirect the network traffic,
> implementing
> a "virtual interrupt" mechanism whereby the host could cause the guest OS to
> "see"
> a hardware interrupt and of course, writing a NIC driver for windows that
> will
> work with Plex86 (and provide a suitable NIC address - one that won't
> conflict with
> the rest of the LAN).
>
> I just had another thought. There's no reason why the sends and receives
> could not
> work at the ethernet, except that the host would have to recognize both its
> own NIC
> address and the Guest NIC address - could be done in promiscuous mode, with
> the host
> driver filtering (this could be costly in machine cycles)... In this case,
> we would
> have to make sure that the host driver would recognize its own NIC address,
> and
> loop-back any packets that the Guest sent to it.
>
> Either way, we would want a virtual card for windows, and a driver to handle
> it, a
> virtual interrupt mechanism, PCI spoofing, a communication mechanism to the
> host
> from the guest and vice-versa. Thinking about it, PCI spoofing is probably
> going to
> play a big role in peripheral handling, whatever it is. This is probably a
> VIP
> (Very Important sub-Project).
