X-Git-Url: http://v3vee.org/palacios/gitweb/gitweb.cgi?a=blobdiff_plain;f=palacios%2Fsrc%2Fpalacios%2Fsvm_halt.c;h=2e6f9e2eaf8363971e5eb8d18884c6cc1da5c238;hb=afffedf9ab57494864f0710a2530958fa9e216cc;hp=3c893d3d848149b82144e53165e11d21d8bb426a;hpb=fa7a42a55338e5fa49ec760b367225ca752df4fd;p=palacios.git

diff --git a/palacios/src/palacios/svm_halt.c b/palacios/src/palacios/svm_halt.c
index 3c893d3..2e6f9e2 100644
--- a/palacios/src/palacios/svm_halt.c
+++ b/palacios/src/palacios/svm_halt.c
@@ -1,36 +1,76 @@
+/* 
+ * This file is part of the Palacios Virtual Machine Monitor developed
+ * by the V3VEE Project with funding from the United States National 
+ * Science Foundation and the Department of Energy.  
+ *
+ * The V3VEE Project is a joint project between Northwestern University
+ * and the University of New Mexico.  You can find out more at 
+ * http://www.v3vee.org
+ *
+ * Copyright (c) 2008, Peter Dinda <pdinda@northwestern.edu>
+ * Copyright (c) 2008, Jack Lange <jarusl@cs.northwestern.edu> 
+ * Copyright (c) 2008, The V3VEE Project <http://www.v3vee.org> 
+ * All rights reserved.
+ *
+ * Author: Peter Dinda <pdinda@northwestern.edu>
+ *
+ * This is free software.  You are permitted to use,
+ * redistribute, and modify it as specified in the file "V3VEE_LICENSE".
+ */
+
 #include <palacios/svm_halt.h>
 #include <palacios/vmm_intr.h>
-// From GeekOS
-void Yield(void);
-
-
-int handle_svm_halt(struct guest_info * info)
-{
-  // 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;
-  uint32_t gap = 0;
+#ifndef DEBUG_HALT
+#undef PrintDebug
+#define PrintDebug(fmt, args...)
+#endif
 
-  PrintDebug("GeekOS Yield\n");
 
-  rdtscll(yield_start);
-  Yield();
-  rdtscll(yield_stop);
 
+//
+// This should trigger a #GP if cpl != 0, otherwise, yield to host
+//
 
-  //v3_update_time(info, yield_stop - yield_start);
-  gap = yield_stop - yield_start;
-  v3_raise_irq(info, 0);
+int v3_handle_svm_halt(struct guest_info * info) {
 
-  PrintDebug("GeekOS Yield Done (%d cycles)\n", gap);
+    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;
 
-  info->rip+=1;
+	/*  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);
+	}
 
-  return 0;
+	
+	PrintDebug("CPU Yield Done (%d cycles)\n", gap);
+	
+	info->rip+=1;
+    }
 
+    return 0;
 }