- uint64_t now = qemu_get_clock_ns(rt_clock);
- int requeued = 0;
- struct mbuf *ifm, *ifqt;
-
- DEBUG_CALL("if_start");
-
- if (slirp->if_queued == 0)
- return; /* Nothing to do */
-
- again:
- /* check if we can really output */
- if (!slirp_can_output(slirp->opaque))
- return;
+ uint64_t now = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);
+ bool from_batchq, next_from_batchq;
+ struct mbuf *ifm, *ifm_next, *ifqt;
+
+ DEBUG_CALL("if_start");
+
+ if (slirp->if_start_busy) {
+ return;
+ }
+ slirp->if_start_busy = true;
+
+ if (slirp->if_fastq.ifq_next != &slirp->if_fastq) {
+ ifm_next = slirp->if_fastq.ifq_next;
+ next_from_batchq = false;
+ } else if (slirp->next_m != &slirp->if_batchq) {
+ /* Nothing on fastq, pick up from batchq via next_m */
+ ifm_next = slirp->next_m;
+ next_from_batchq = true;
+ } else {
+ ifm_next = NULL;
+ }
+
+ while (ifm_next) {
+ ifm = ifm_next;
+ from_batchq = next_from_batchq;
+
+ ifm_next = ifm->ifq_next;
+ if (ifm_next == &slirp->if_fastq) {
+ /* No more packets in fastq, switch to batchq */
+ ifm_next = slirp->next_m;
+ next_from_batchq = true;
+ }
+ if (ifm_next == &slirp->if_batchq) {
+ /* end of batchq */
+ ifm_next = NULL;
+ }