On Fri, Nov 22, 2013 at 06:47:49PM +0400, Dmitry Smagin wrote:
> From: Antony Pavlov <antonynpav...@gmail.com>
>
> This patch adds emulation of DEC/Intel Tulip 21143 with some external chips:
> * Intel LXT971A 10/100 Mbps PHY MII Tranceiver;
> * Microchip 93LC46B 1K Microwire Compatible Serial EEPROM.
>
> Restrictions and TODOs:
> - Tulip always work in promisc-mode with no packet filtering
> (TODO: check qemu packet filtering interfaces)
>
> - Address errors in packet descriptors are not checked
>
> - Tulip is bound to PCI, no other bus is possible for now
> (TODO: Rewrite code to permit Tulip to live on buses other than PCI)
>
> - Internal transceiver is not emulated
> The reason: internal transceiver works with 10 Mbps but we need 100Mbps
> which only external transceivers can give.
>
> - Link status is not emulated, it's always ON
> (TODO: use standard qemu interface)
>
> - Incorrect behavior of the Tulip driver is not checked and there's no error
> signaling via register CSR5
>
> - Only transfer/receive (TI/RI) interrupts are emulated
>
> - Subsystem IDs in EEPROM image are not good
> (TODO: find proper IDs)
The NIC needs to tell QEMU when it transitions from a rx descriptors
exhausted state to a rx refilled state. For example, the e1000 NIC
calls qemu_flush_queued_packets(qemu_get_queue(s->nic)) when the RDT
hardware register is written to by the guest.
This is necessary since the netdev (e.g. tap) disables receive when the
NIC runs out of rx descriptors.
> +static const VMStateDescription vmstate_tulip = {
> + .name = "tulip",
> + .version_id = 2,
> + .minimum_version_id = 1,
> + .minimum_version_id_old = 1,
> + .fields = (VMStateField[]) {
> + VMSTATE_PCI_DEVICE(dev, TulipState),
> + VMSTATE_MACADDR(conf.macaddr, TulipState),
This looks a little sparse :). Other hardware registers probably need
to be saved/loaded too.
