X-Git-Url: http://v3vee.org/palacios/gitweb/gitweb.cgi?p=palacios.git;a=blobdiff_plain;f=palacios%2Fsrc%2Fpalacios%2Fsvm_halt.c;h=2e6f9e2eaf8363971e5eb8d18884c6cc1da5c238;hp=16239e841df7571aed22a20b5156f8cc670f1d37;hb=afffedf9ab57494864f0710a2530958fa9e216cc;hpb=13fb068168e2826db39a481cf85033bb0156d2f9

diff --git a/palacios/src/palacios/svm_halt.c b/palacios/src/palacios/svm_halt.c
index 16239e8..2e6f9e2 100644
--- a/palacios/src/palacios/svm_halt.c
+++ b/palacios/src/palacios/svm_halt.c
@@ -30,7 +30,7 @@
 
 
 //
-// 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) {
@@ -39,8 +39,8 @@ int v3_handle_svm_halt(struct guest_info * info) {
 	v3_raise_exception(info, GPF_EXCEPTION);
     } else {
     
-	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");
@@ -53,7 +53,18 @@ int v3_handle_svm_halt(struct guest_info * info) {
 	//v3_update_time(info, yield_stop - yield_start);
 	gap = yield_stop - yield_start;
 
-	v3_raise_irq(info, 0);
+	/*  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);