X-Git-Url: http://v3vee.org/palacios/gitweb/gitweb.cgi?a=blobdiff_plain;f=palacios%2Fsrc%2Fpalacios%2Fvmm_halt.c;h=7970a404f4e877c078411086b0d828ad883bf927;hb=4af50228c3683df4d542ee79d5747ed51840ef0c;hp=056d5682fd4388d3d50e57056b4527588cca5797;hpb=3e5e5a12e64630d7a37ed32b8d7e2d993c79f7e0;p=palacios.git

diff --git a/palacios/src/palacios/vmm_halt.c b/palacios/src/palacios/vmm_halt.c
index 056d568..7970a40 100644
--- a/palacios/src/palacios/vmm_halt.c
+++ b/palacios/src/palacios/vmm_halt.c
@@ -38,36 +38,22 @@ int v3_handle_halt(struct guest_info * info) {
     if (info->cpl != 0) { 
 	v3_raise_exception(info, GPF_EXCEPTION);
     } else {
-    
-	uint64_t yield_start = 0;
-	uint64_t yield_stop = 0;
-	uint32_t gap = 0;
-	
 	PrintDebug("CPU Yield\n");
-	
-	rdtscll(yield_start);
-	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_advance_time(info);
+	while (!v3_intr_pending(info)) {
+	    /* Since we're in an exit, time is already paused here, so no need to pause again. */
+	    v3_yield(info);
+	    v3_update_timers(info);
+	    
+	    /* At this point, we either have some combination of 
+	       interrupts, including perhaps a timer interrupt, or 
+	       no interrupt.
+	    */
+	    if (!v3_intr_pending(info)) {
+		/* if no interrupt, then we do halt */
+		asm("hlt");
+	    }
 	}
-
-	
-	PrintDebug("CPU Yield Done (%d cycles)\n", gap);
 	
 	info->rip += 1;
     }