viostor: Move from msix_one_vector to msix_has_config_vector

What makes msix_one_vector really different from other cases in the code
is just that it means that MSI isn't used for config changes and so the
vector indices move by one (because the config vector is 0 and all the
queue vectors start from 1 then, whereas without the config vector, the
vectors for queues already start from 0).

If we wanted, we could have multiple vectors in use even without a
config vector, and that's actually a very good idea when we have less
vectors than num_queues + 1. msix_one_vector isn't a very good name any
more then.

So let's have an adaptExt->msix_has_config_vector instead.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>

Author: kevmw

viostor/virtio_pci.c

@@ -231,20 +231,13 @@ static u16 vdev_get_msix_vector(void *context, int queue)
         /* queue interrupt */
         if (adaptExt->msix_enabled)
         {
-            if (adaptExt->msix_one_vector)
-            {
-                vector = 0;
-            }
-            else
-            {
-                vector = queue + 1;
-            }
+            vector = adaptExt->msix_has_config_vector ? queue + 1 : queue;
         }
     }
     else
     {
         /* on-device-config-change interrupt */
-        if (!adaptExt->msix_one_vector)
+        if (adaptExt->msix_has_config_vector)
         {
             vector = VIRTIO_BLK_MSIX_CONFIG_VECTOR;
         }

viostor/virtio_stor.c

@@ -709,13 +709,14 @@ VirtIoHwInitialize(IN PVOID DeviceExtension)
     {
         /* initialize queues with a MSI vector per queue */
         RhelDbgPrint(TRACE_LEVEL_INFORMATION, (" Using a unique MSI vector per queue\n"));
-        adaptExt->msix_one_vector = FALSE;
+        adaptExt->msix_has_config_vector = TRUE;
     }
     else
     {
         /* if we don't have enough vectors, use one for all queues */
+        RhelDbgPrint(TRACE_LEVEL_INFORMATION, (" Disabling MSI config vector\n"));
         RhelDbgPrint(TRACE_LEVEL_INFORMATION, (" Using one MSI vector for all queues\n"));
-        adaptExt->msix_one_vector = TRUE;
+        adaptExt->msix_has_config_vector = FALSE;
         /* TODO Allow using multiple queues even with a single vector */
         adaptExt->num_queues = 1;
     }
@@ -770,7 +771,7 @@ VirtIoHwInitialize(IN PVOID DeviceExtension)
                 if (CHECKFLAG(perfData.Flags, STOR_PERF_INTERRUPT_MESSAGE_RANGES))
                 {
                     adaptExt->perfFlags |= STOR_PERF_INTERRUPT_MESSAGE_RANGES;
-                    perfData.FirstRedirectionMessageNumber = adaptExt->msix_one_vector ? 0 : 1;
+                    perfData.FirstRedirectionMessageNumber = adaptExt->msix_has_config_vector ? 1 : 0;
                     perfData.LastRedirectionMessageNumber = perfData.FirstRedirectionMessageNumber +
                                                             adaptExt->num_queues - 1;
                     ASSERT(perfData.lastRedirectionMessageNumber < adaptExt->num_affinity);
@@ -1259,9 +1260,9 @@ VirtIoInterrupt(IN PVOID DeviceExtension)
     intReason = virtio_read_isr_status(&adaptExt->vdev);
     if (intReason == 1 || adaptExt->dump_mode)
     {
-        if (!CompleteDPC(DeviceExtension, !adaptExt->msix_one_vector))
+        if (!CompleteDPC(DeviceExtension, adaptExt->msix_has_config_vector))
         {
-            VioStorCompleteRequest(DeviceExtension, !adaptExt->msix_one_vector, TRUE);
+            VioStorCompleteRequest(DeviceExtension, adaptExt->msix_has_config_vector, TRUE);
         }
         isInterruptServiced = TRUE;
     }
@@ -1584,7 +1585,7 @@ VirtIoMSInterruptRoutine(IN PVOID DeviceExtension, IN ULONG MessageID)
         return FALSE;
     }
 
-    if (!adaptExt->msix_one_vector && MessageID == VIRTIO_BLK_MSIX_CONFIG_VECTOR)
+    if (adaptExt->msix_has_config_vector && MessageID == VIRTIO_BLK_MSIX_CONFIG_VECTOR)
     {
         RhelGetDiskGeometry(DeviceExtension);
         adaptExt->sense_info.senseKey = SCSI_SENSE_UNIT_ATTENTION;
@@ -2179,7 +2180,7 @@ VOID VioStorCompleteRequest(IN PVOID DeviceExtension, IN ULONG MessageID, IN BOO
 {
     unsigned int len = 0;
     PADAPTER_EXTENSION adaptExt = (PADAPTER_EXTENSION)DeviceExtension;
-    ULONG QueueNumber = adaptExt->msix_one_vector ? MessageID : MessageID - 1;
+    ULONG QueueNumber = MessageID - adaptExt->msix_has_config_vector;
     STOR_LOCK_HANDLE queueLock = {0};
     struct virtqueue *vq = NULL;
     ULONG_PTR srbId = 0;

viostor/virtio_stor.h

@@ -231,7 +231,8 @@ typedef struct _ADAPTER_EXTENSION
     BOOLEAN dump_mode;
     ULONG msix_vectors;
     BOOLEAN msix_enabled;
-    BOOLEAN msix_one_vector;
+    /* Standard C type because we do arithmetics with it */
+    _Bool msix_has_config_vector;
     ULONGLONG features;
     CHAR sn[BLOCK_SERIAL_STRLEN];
     BOOLEAN sn_ok;

viostor/virtio_stor_hw_helper.h

@@ -73,7 +73,7 @@ static inline ULONG QueueToMessageId(PVOID DeviceExtension, ULONG QueueNumber)
 {
     PADAPTER_EXTENSION adaptExt = (PADAPTER_EXTENSION)DeviceExtension;
 
-    if (!adaptExt->msix_one_vector)
+    if (adaptExt->msix_has_config_vector)
     {
         QueueNumber++;
     }
@@ -90,7 +90,7 @@ static inline ULONG MessageToDpcIdx(PVOID DeviceExtension, ULONG MessageId)
 {
     PADAPTER_EXTENSION adaptExt = (PADAPTER_EXTENSION)DeviceExtension;
 
-    if (!adaptExt->msix_one_vector)
+    if (adaptExt->msix_has_config_vector)
     {
         /* The config vector doesn't have a slot in adaptExt->dpc */
         MessageId--;