From: Peter Dinda <pdinda@northwestern.edu>
Date: Fri, 2 Aug 2013 20:41:13 +0000 (-0500)
Subject: Fixes to interrupt (IRQ and VIRQ) injection logic:
X-Git-Url: http://v3vee.org/palacios/gitweb/gitweb.cgi?a=commitdiff_plain;h=e0711262cc7bef8962813f713d36cc8cabf80cb4;hp=cbe14745457d9a646157633e1fa8eccffe035953;p=palacios.git

Fixes to interrupt (IRQ and VIRQ) injection logic:

- eliminates potential race condition between intr being
  pending when intially checked, and no vector available before
  injection begins

- differentiates "do no have a vector" from "vector 0"

- detects VIRQ 0 correctly if it is raised
---

diff --git a/palacios/include/palacios/vmm_intr.h b/palacios/include/palacios/vmm_intr.h
index de98185..df1750b 100644
--- a/palacios/include/palacios/vmm_intr.h
+++ b/palacios/include/palacios/vmm_intr.h
@@ -28,7 +28,7 @@
 #include <palacios/vmm_lock.h>
 
 
-typedef enum {V3_INVALID_INTR, V3_EXTERNAL_IRQ, V3_VIRTUAL_IRQ, V3_NMI, V3_SOFTWARE_INTR} v3_intr_type_t;
+typedef enum {V3_INVALID_INTR=0, V3_EXTERNAL_IRQ, V3_VIRTUAL_IRQ, V3_NMI, V3_SOFTWARE_INTR} v3_intr_type_t;
 
 struct guest_info;
 struct v3_vm_info;
@@ -121,7 +121,7 @@ void v3_remove_intr_controller(struct guest_info * core, void * handle);
 void v3_remove_intr_router(struct v3_vm_info * vm, void * handle);
 
 v3_intr_type_t v3_intr_pending(struct guest_info * info);
-uint32_t v3_get_intr(struct guest_info * info);
+int v3_get_intr(struct guest_info * info);
 int v3_injecting_intr(struct guest_info * info, uint_t intr_num, v3_intr_type_t type);
 
 
diff --git a/palacios/src/palacios/svm.c b/palacios/src/palacios/svm.c
index 847bb1e..c226e68 100644
--- a/palacios/src/palacios/svm.c
+++ b/palacios/src/palacios/svm.c
@@ -527,7 +527,11 @@ static int update_irq_entry_state(struct guest_info * info) {
     } else {
 	switch (v3_intr_pending(info)) {
 	    case V3_EXTERNAL_IRQ: {
-		uint32_t irq = v3_get_intr(info);
+ 	        int irq = v3_get_intr(info); 
+
+		if (irq<0) {
+		  break;
+		}
 
 		guest_ctrl->guest_ctrl.V_IRQ = 1;
 		guest_ctrl->guest_ctrl.V_INTR_VECTOR = irq;
diff --git a/palacios/src/palacios/vmm_intr.c b/palacios/src/palacios/vmm_intr.c
index 2e78872..ee54bef 100644
--- a/palacios/src/palacios/vmm_intr.c
+++ b/palacios/src/palacios/vmm_intr.c
@@ -369,7 +369,7 @@ v3_intr_type_t v3_intr_pending(struct guest_info * info) {
 
     // External IRQs have lowest priority
     list_for_each_entry(ctrl, &(intr_state->controller_list), ctrl_node) {
-	if (ctrl->ctrl_ops->intr_pending(info, ctrl->priv_data) == 1) {
+	if (ctrl->ctrl_ops->intr_pending(info, ctrl->priv_data)) {
 	    ret = V3_EXTERNAL_IRQ;
 	    break;
 	}
@@ -394,12 +394,14 @@ v3_intr_type_t v3_intr_pending(struct guest_info * info) {
 }
 
 
-uint32_t v3_get_intr(struct guest_info * info) {
+int v3_get_intr(struct guest_info * info) {
     struct v3_intr_core_state * intr_state = &(info->intr_core_state);
     struct intr_controller * ctrl = NULL;
-    uint_t ret = 0;
+    int ret = -1;
     int i = 0;
     int j = 0;
+    int found_virq=0;
+    int found_irq=0;
 
     addr_t irq_state = v3_lock_irqsave(intr_state->irq_lock);    
 
@@ -409,6 +411,8 @@ uint32_t v3_get_intr(struct guest_info * info) {
 	    for (j = 0; j < 8; j++) {
 		if (intr_state->virq_map[i] & (1 << j)) {
 		    ret = (i * 8) + j;
+		    // need to be able to find virq 0
+		    found_virq=1;
 		    break;
 		}
 	    }
@@ -416,20 +420,28 @@ uint32_t v3_get_intr(struct guest_info * info) {
 	}
     }
 
-    if (!ret) {
+    if (!found_virq) {
 	list_for_each_entry(ctrl, &(intr_state->controller_list), ctrl_node) {
 	    if (ctrl->ctrl_ops->intr_pending(info, ctrl->priv_data)) {
-		uint_t intr_num = ctrl->ctrl_ops->get_intr_number(info, ctrl->priv_data);
+		int intr_num = ctrl->ctrl_ops->get_intr_number(info, ctrl->priv_data);
 		
-		//	PrintDebug(info->vm_info, info, "[get_intr_number] intr_number = %d\n", intr_num);
-		ret = intr_num;
-		break;
+		if (intr_num >= 0) {
+		  //	PrintDebug(info->vm_info, info, "[get_intr_number] intr_number = %d\n", intr_num);
+		  ret = intr_num;
+		  found_irq=1;
+		  break;
+		}
+
 	    }
 	}
     }
 
     v3_unlock_irqrestore(intr_state->irq_lock, irq_state);
 
+    if (!found_virq && !found_irq) { 
+      PrintError(info->vm_info,info,"Strange... neither a VIRQ nor an IRQ was found...\n");
+    }
+
     return ret;
 }
 
diff --git a/palacios/src/palacios/vmx.c b/palacios/src/palacios/vmx.c
index 2741051..2653af0 100644
--- a/palacios/src/palacios/vmx.c
+++ b/palacios/src/palacios/vmx.c
@@ -820,7 +820,14 @@ static int update_irq_entry_state(struct guest_info * info) {
 
             switch (v3_intr_pending(info)) {
                 case V3_EXTERNAL_IRQ: {
-                    info->intr_core_state.irq_vector = v3_get_intr(info); 
+		  
+ 	            int irq = v3_get_intr(info); 
+
+		    if (irq<0) {
+		      break;
+		    }
+
+                    info->intr_core_state.irq_vector = irq; 
                     ent_int.vector = info->intr_core_state.irq_vector;
                     ent_int.type = 0;
                     ent_int.error_code = 0;