From: Lei Xia <lxia@northwestern.edu>
Date: Fri, 23 Apr 2010 18:12:07 +0000 (-0500)
Subject: Fix to the HLT exit handler
X-Git-Url: http://v3vee.org/palacios/gitweb/gitweb.cgi?a=commitdiff_plain;h=46113012016d5064ca8617dbb39f04c9763fd911;p=palacios.git

Fix to the HLT exit handler
---

diff --git a/palacios/include/palacios/vmm_time.h b/palacios/include/palacios/vmm_time.h
index ff4946a..d805db9 100644
--- a/palacios/include/palacios/vmm_time.h
+++ b/palacios/include/palacios/vmm_time.h
@@ -36,6 +36,13 @@ struct vm_time {
     // Cache value to help calculate the guest_tsc
     ullong_t cached_host_tsc;
 
+	
+    /* The total num of numcycles spent in the halt handler 
+    	  that the halt handler has already updated to the 
+    	  timer infrastructure about.   That is, "update_time" has been
+     */
+    ullong_t cached_hlt_tsc;
+
     // The number of cycles pending for notification to the timers
     //ullong_t pending_cycles;
 
diff --git a/palacios/src/palacios/svm.c b/palacios/src/palacios/svm.c
index 6de0781..b6bd770 100644
--- a/palacios/src/palacios/svm.c
+++ b/palacios/src/palacios/svm.c
@@ -468,7 +468,8 @@ int v3_svm_enter(struct guest_info * info) {
 
 
     rdtscll(tmp_tsc);
-    v3_update_time(info, tmp_tsc - info->time_state.cached_host_tsc);
+    v3_update_time(info, (tmp_tsc - info->time_state.cached_host_tsc - info->time_state.cached_hlt_tsc));
+    info->time_state.cached_hlt_tsc = 0;
     rdtscll(info->time_state.cached_host_tsc);
     //    guest_ctrl->TSC_OFFSET = info->time_state.guest_tsc - info->time_state.cached_host_tsc;
 
diff --git a/palacios/src/palacios/vmm_halt.c b/palacios/src/palacios/vmm_halt.c
index 056d568..bb28ebc 100644
--- a/palacios/src/palacios/vmm_halt.c
+++ b/palacios/src/palacios/vmm_halt.c
@@ -44,6 +44,8 @@ int v3_handle_halt(struct guest_info * info) {
 	uint32_t gap = 0;
 	
 	PrintDebug("CPU Yield\n");
+
+again:
 	
 	rdtscll(yield_start);
 	v3_yield(info);
@@ -52,7 +54,26 @@ int v3_handle_halt(struct guest_info * info) {
     
 	//v3_update_time(info, yield_stop - yield_start);
 	gap = yield_stop - yield_start;
+	 /*
+           If we got here, either an interrupt has occured or
+           sufficient time has passed that we may need to inject 
+           a timer interrupt.  
+           First, we will update time, which may or may not inject an
+           interrupt 
+        */
+	v3_update_time(info, gap);
+	info->time_state.cached_hlt_tsc += gap;
 
+	/* 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 yield again */
+	    goto again;
+	}
+
+#if 0
 	/*  WARNING!!! WARNING!!!
 	 *  
 	 * DO NOT REMOVE THIS CONDITIONAL!!!
@@ -65,7 +86,9 @@ int v3_handle_halt(struct guest_info * info) {
 	if (!v3_intr_pending(info)) {
 	    v3_advance_time(info);
 	}
+#endif
 
+      //PrintError("HLT instruction issued\n");
 	
 	PrintDebug("CPU Yield Done (%d cycles)\n", gap);
 	
diff --git a/palacios/src/palacios/vmx.c b/palacios/src/palacios/vmx.c
index 253ae47..3334d2f 100644
--- a/palacios/src/palacios/vmx.c
+++ b/palacios/src/palacios/vmx.c
@@ -660,7 +660,8 @@ int v3_vmx_enter(struct guest_info * info) {
 
     // We do timer injection here to track real host time.
     rdtscll(tmp_tsc);
-    v3_update_time(info, tmp_tsc - info->time_state.cached_host_tsc);
+    v3_update_time(info, tmp_tsc - info->time_state.cached_host_tsc - info->time_state.cached_hlt_tsc);
+    info->time_state.cached_hlt_tsc = 0;
     rdtscll(info->time_state.cached_host_tsc);
 
     if (info->vm_info->run_state == VM_STOPPED) {