[PATCH v4 5/7] OvmfPkg/VirtioMmioDeviceLib: virtio 1.0: Add default QueueNum

["Gerd Hoffmann" <kraxel@redhat.com>]

Use QueueNumMax as QueueNum default for drivers which do not
explicitly call VIRTIO_DEVICE_PROTOCOL->SetQueueSize().

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 .../Library/VirtioMmioDeviceLib/VirtioMmioDevice.h   |  1 +
 .../VirtioMmioDeviceLib/VirtioMmioDeviceFunctions.c  | 12 +++++++++++-
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/OvmfPkg/Library/VirtioMmioDeviceLib/VirtioMmioDevice.h b/OvmfPkg/Library/VirtioMmioDeviceLib/VirtioMmioDevice.h
index 0c2f99633c46..5ad951f4154a 100644
--- a/OvmfPkg/Library/VirtioMmioDeviceLib/VirtioMmioDevice.h
+++ b/OvmfPkg/Library/VirtioMmioDeviceLib/VirtioMmioDevice.h
@@ -30,6 +30,7 @@
 typedef struct {
   UINT32                 Signature;
   UINT32                 Version;
+  UINT16                 QueueNum;
   VIRTIO_DEVICE_PROTOCOL VirtioDevice;
   PHYSICAL_ADDRESS       BaseAddress;
 } VIRTIO_MMIO_DEVICE;
diff --git a/OvmfPkg/Library/VirtioMmioDeviceLib/VirtioMmioDeviceFunctions.c b/OvmfPkg/Library/VirtioMmioDeviceLib/VirtioMmioDeviceFunctions.c
index a0ee8e5f3c86..b4711f9b42e6 100644
--- a/OvmfPkg/Library/VirtioMmioDeviceLib/VirtioMmioDeviceFunctions.c
+++ b/OvmfPkg/Library/VirtioMmioDeviceLib/VirtioMmioDeviceFunctions.c
@@ -83,7 +83,11 @@ VirtioMmioSetQueueSize (
 
   Device = VIRTIO_MMIO_DEVICE_FROM_VIRTIO_DEVICE (This);
 
-  VIRTIO_CFG_WRITE (Device, VIRTIO_MMIO_OFFSET_QUEUE_NUM, QueueSize);
+  if (Device->Version == VIRTIO_MMIO_DEVICE_VERSION_0_95) {
+    VIRTIO_CFG_WRITE (Device, VIRTIO_MMIO_OFFSET_QUEUE_NUM, QueueSize);
+  } else {
+    Device->QueueNum = QueueSize;
+  }
 
   return EFI_SUCCESS;
 }
@@ -171,6 +175,10 @@ VirtioMmioSetQueueSel (
 
   VIRTIO_CFG_WRITE (Device, VIRTIO_MMIO_OFFSET_QUEUE_SEL, Sel);
 
+  if (Device->Version == VIRTIO_MMIO_DEVICE_VERSION_0_95) {
+    Device->QueueNum = VIRTIO_CFG_READ (Device, VIRTIO_MMIO_OFFSET_QUEUE_NUM_MAX) & 0xFFFF;
+  }
+
   return EFI_SUCCESS;
 }
 
@@ -193,6 +201,8 @@ VirtioMmioSetQueueAddress (
     VIRTIO_CFG_WRITE (Device, VIRTIO_MMIO_OFFSET_QUEUE_PFN,
       (UINT32)((UINTN)Ring->Base >> EFI_PAGE_SHIFT));
   } else {
+    VIRTIO_CFG_WRITE (Device, VIRTIO_MMIO_OFFSET_QUEUE_NUM, Device->QueueNum);
+
     Address = (UINT64)Ring->Base;
     VIRTIO_CFG_WRITE (Device, VIRTIO_MMIO_OFFSET_QUEUE_DESC_LO,
                       (UINT32)Address);
-- 
2.31.1