X-Git-Url: http://v3vee.org/palacios/gitweb/gitweb.cgi?a=blobdiff_plain;f=palacios%2Fsrc%2Fpalacios%2Fvmm_halt.c;h=445f43fecfd6437161a7aa856888071fd93b27db;hb=40a6dd36505a959c132c32497aa50bd74afd8250;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..445f43f 100644
--- a/palacios/src/palacios/vmm_halt.c
+++ b/palacios/src/palacios/vmm_halt.c
@@ -20,56 +20,72 @@
 
 #include <palacios/vmm_halt.h>
 #include <palacios/vmm_intr.h>
+#include <palacios/vmm_lowlevel.h> 
+#include <palacios/vmm_perftune.h>
 
-
-#ifndef CONFIG_DEBUG_HALT
+#ifndef V3_CONFIG_DEBUG_HALT
 #undef PrintDebug
 #define PrintDebug(fmt, args...)
 #endif
 
 
-
 //
 // This should trigger a #GP if cpl != 0, otherwise, yield to host
 //
 
-int v3_handle_halt(struct guest_info * info) {
-
+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");
+	uint64_t start_cycles;
 	
-	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);
+	PrintDebug(info->vm_info, info, "CPU Yield\n");
+
+	start_cycles  = v3_get_host_time(&info->time_state);
+
+	while (!v3_intr_pending(info) &&
+	       !v3_excp_pending(info) &&
+	       (info->vm_info->run_state == VM_RUNNING)) {
+            uint64_t t, cycles;
+
+	    t = v3_get_host_time(&info->time_state);
+
+	    /* Yield, allowing time to pass while yielded */
+	    v3_strategy_driven_yield(info, v3_cycle_diff_in_usec(info, start_cycles, t));
+
+	    cycles = v3_get_host_time(&info->time_state) - t;
+
+	    v3_advance_time(info, &cycles);
+
+	    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"); */
+	    }
+
+	    // participate in any barrier that might be raised
+	    v3_wait_at_barrier(info);
+
+	    // stop if the VM is being halted or core is being reset
+	    if (info->core_run_state == CORE_STOPPED || info->core_run_state == CORE_RESETTING) { 
+		break;
+	    }
+
 	}
 
-	
-	PrintDebug("CPU Yield Done (%d cycles)\n", gap);
+	/* V3_Print(info->vm_info, info, "palacios: done with halt\n"); */
 	
 	info->rip += 1;
+	
     }
 
     return 0;