Suppress the peer notifications while a ring keeps delivering work, batch
the receive completions into one kick per burst and drop the redundant
txdone signal from the transmit path. Validate the peer controlled frame
lengths, accept descriptor chains on both lanes, keep every ring access on
the upper half's work thread so the interrupt context callbacks stay lock
free, and prefer the MAC from the configuration space, falling back to the
Kconfig address or a random one.
Signed-off-by: zhanghongyu <zhanghongyu@xiaomi.com>
Implements the device end of virtio-net, so a peer running the stock
virtio-net driver sees this side as a network card, and registers a netdev
lowerhalf.
Ring layout follows the peer's numbering: vq[0] is its RX queue, which we fill
to transmit, and vq[1] its TX queue, which we harvest. No features are
negotiated, so every frame carries the zeroed legacy virtio_net_hdr.
Peer buffers are reached by raw 64-bit address through an arch-provided
translation window -- the AM67 RAT, identity mapping elsewhere -- splitting
copies that straddle it.
Also gives DRIVERS_VHOST a prompt; it was promptless and so unselectable
without a driver forcing it.
Verified on t3-gem-o1 against an unmodified Linux virtio_net: eth0 registers,
ifup brings it to RUNNING, and the peer pings it 5/5 at 0.27 ms and 60/60 with
0% loss.
Assisted-by: Claude Code:claude-fable-5
Signed-off-by: Ulaş Sertan Kemeç <sertan.usk@gmail.com>
