//
-// This should trigger a #GP if cpl!=0, otherwise, yield to host
+// This should trigger a #GP if cpl != 0, otherwise, yield to host
//
-int v3_handle_svm_halt(struct guest_info * info)
-{
- if (info->cpl!=0) {
+int v3_handle_svm_halt(struct guest_info * info) {
+
+ if (info->cpl != 0) {
v3_raise_exception(info, GPF_EXCEPTION);
} else {
- // What we should do is starting waiting on an OS event that will
- // result in an injection of an interrupt.
-
- // What we will hackishly do instead is resume on any event
- // Plus is this totally GeekOS specific
-
- ullong_t yield_start = 0;
- ullong_t yield_stop = 0;
+ uint64_t yield_start = 0;
+ uint64_t yield_stop = 0;
uint32_t gap = 0;
PrintDebug("CPU Yield\n");
rdtscll(yield_start);
- V3_Yield();
+ v3_yield(info);
rdtscll(yield_stop);
//v3_update_time(info, yield_stop - yield_start);
gap = yield_stop - yield_start;
+
+ /* WARNING!!! WARNING!!!
+ *
+ * DO NOT REMOVE THIS CONDITIONAL!!!
+ *
+ * It is common for an OS to issue an IO op, and then sit in a halt loop
+ * waiting for the device to complete and raise an irq.
+ * If you remove this then the timer interrupt will ALWAYS subvert the completion
+ * interrupt and stall the guest.
+ */
if (!v3_intr_pending(info)) {
v3_raise_irq(info, 0);
}
+
PrintDebug("CPU Yield Done (%d cycles)\n", gap);
info->rip+=1;
}
+
return 0;
}