vmw_balloon: VMCI_DOORBELL_SET does not check status

When vmballoon_vmci_init() sets a doorbell using VMCI_DOORBELL_SET, for some reason it does not consider the status and looks at the result. However, the hypervisor does not update the result - it updates the status. This might cause VMCI doorbell not to be enabled, resulting in degraded performance. Fixes: 48e3d66 ("VMware balloon: Enable notification via VMCI") Cc: [email protected] Reviewed-by: Xavier Deguillard <[email protected]> Signed-off-by: Nadav Amit <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
numbqq · Jul 3, 2018 · ce66433 · ce66433
1 parent 5081efd
commit ce66433
Showing 1 changed file with 19 additions and 18 deletions.
diff --git a/drivers/misc/vmw_balloon.c b/drivers/misc/vmw_balloon.c
@@ -1036,29 +1036,30 @@ static void vmballoon_vmci_cleanup(struct vmballoon *b)
  */
 static int vmballoon_vmci_init(struct vmballoon *b)
 {
-	int error = 0;
+	unsigned long error, dummy;
 
-	if ((b->capabilities & VMW_BALLOON_SIGNALLED_WAKEUP_CMD) != 0) {
-		error = vmci_doorbell_create(&b->vmci_doorbell,
-				VMCI_FLAG_DELAYED_CB,
-				VMCI_PRIVILEGE_FLAG_RESTRICTED,
-				vmballoon_doorbell, b);
-
-		if (error == VMCI_SUCCESS) {
-			VMWARE_BALLOON_CMD(VMCI_DOORBELL_SET,
-					b->vmci_doorbell.context,
-					b->vmci_doorbell.resource, error);
-			STATS_INC(b->stats.doorbell_set);
-		}
-	}
+	if ((b->capabilities & VMW_BALLOON_SIGNALLED_WAKEUP_CMD) == 0)
+		return 0;
 
-	if (error != 0) {
-		vmballoon_vmci_cleanup(b);
+	error = vmci_doorbell_create(&b->vmci_doorbell, VMCI_FLAG_DELAYED_CB,
+				     VMCI_PRIVILEGE_FLAG_RESTRICTED,
+				     vmballoon_doorbell, b);
 
-		return -EIO;
-	}
+	if (error != VMCI_SUCCESS)
+		goto fail;
+
+	error = VMWARE_BALLOON_CMD(VMCI_DOORBELL_SET, b->vmci_doorbell.context,
+				   b->vmci_doorbell.resource, dummy);
+
+	STATS_INC(b->stats.doorbell_set);
+
+	if (error != VMW_BALLOON_SUCCESS)
+		goto fail;
 
 	return 0;
+fail:
+	vmballoon_vmci_cleanup(b);
+	return -EIO;
 }
 
 /*