/* Read from a Netmap device, creating a new packet.
TODO: avoid extra copy by holding netmap buffer. Also
investigate zero copy. */
struct fp_packet*
fp_netmap_recv(struct fp_device* device)
{
struct fp_netmap_device* dev = (struct fp_netmap_device*)device;
unsigned char const* src;
unsigned char* dst;
struct fp_packet* packet;
src = nm_nextpkt(dev->handle, &dev->header);
if (src == NULL)
return NULL; /* nothing waiting */
/* Copy the buffer and create a new packet for it. */
dst = (unsigned char*)malloc(dev->header.len);
memcpy(dst, src, dev->header.len);
/* Allocate a flowpath packet. */
/* TODO: replace dev_handle(NULL) with netmap buffer */
/* TODO: retrieve timestamp from ring */
packet = fp_packet_create(dst, dev->header.len, 0
NULL, FP_BUF_NETMAP);
return packet;
}
static void
pci_vtnet_netmap_rx(struct pci_vtnet_softc *sc)
{
struct iovec iov[VTNET_MAXSEGS], *riov;
struct vqueue_info *vq;
void *vrx;
int len, n;
uint16_t idx;
/*
* Should never be called without a valid netmap descriptor
*/
assert(sc->vsc_nmd != NULL);
/*
* But, will be called when the rx ring hasn't yet
* been set up or the guest is resetting the device.
*/
if (!sc->vsc_rx_ready || sc->resetting) {
/*
* Drop the packet and try later.
*/
(void) nm_nextpkt(sc->vsc_nmd, (void *)dummybuf);
return;
}
/*
* Check for available rx buffers
*/
vq = &sc->vsc_queues[VTNET_RXQ];
if (!vq_has_descs(vq)) {
/*
* Drop the packet and try later. Interrupt on
* empty, if that's negotiated.
*/
(void) nm_nextpkt(sc->vsc_nmd, (void *)dummybuf);
vq_endchains(vq, 1);
return;
}
do {
/*
* Get descriptor chain.
*/
n = vq_getchain(vq, &idx, iov, VTNET_MAXSEGS, NULL);
assert(n >= 1 && n <= VTNET_MAXSEGS);
/*
* Get a pointer to the rx header, and use the
* data immediately following it for the packet buffer.
*/
vrx = iov[0].iov_base;
riov = rx_iov_trim(iov, &n, sc->rx_vhdrlen);
len = pci_vtnet_netmap_readv(sc->vsc_nmd, riov, n);
if (len == 0) {
/*
* No more packets, but still some avail ring
* entries. Interrupt if needed/appropriate.
*/
vq_retchain(vq);
vq_endchains(vq, 0);
return;
}
/*
* The only valid field in the rx packet header is the
* number of buffers if merged rx bufs were negotiated.
*/
memset(vrx, 0, sc->rx_vhdrlen);
if (sc->rx_merge) {
struct virtio_net_rxhdr *vrxh;
vrxh = vrx;
vrxh->vrh_bufs = 1;
}
/*
* Release this chain and handle more chains.
*/
vq_relchain(vq, idx, len + sc->rx_vhdrlen);
} while (vq_has_descs(vq));
/* Interrupt if needed, including for NOTIFY_ON_EMPTY. */
vq_endchains(vq, 1);
}
