[PATCH v3 07/17] OvmfPkg/PvScsiDxe: Translate Target & LUN to/from DevicePath

["Liran Alon" <liran.alon@oracle.com>]

Implement EXT_SCSI_PASS_THRU.BuildDevicePath() and
EXT_SCSI_PASS_THRU.GetTargetLun().

Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=2567
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Liran Alon <liran.alon@oracle.com>
---
 OvmfPkg/PvScsiDxe/PvScsi.c | 61 ++++++++++++++++++++++++++++++++++++--
 1 file changed, 59 insertions(+), 2 deletions(-)

diff --git a/OvmfPkg/PvScsiDxe/PvScsi.c b/OvmfPkg/PvScsiDxe/PvScsi.c
index 7f51ada19a1a..76fc1eb910f2 100644
--- a/OvmfPkg/PvScsiDxe/PvScsi.c
+++ b/OvmfPkg/PvScsiDxe/PvScsi.c
@@ -137,7 +137,38 @@ PvScsiBuildDevicePath (
   IN OUT EFI_DEVICE_PATH_PROTOCOL                   **DevicePath
   )
 {
-  return EFI_UNSUPPORTED;
+  UINT8             TargetValue;
+  PVSCSI_DEV        *Dev;
+  SCSI_DEVICE_PATH  *ScsiDevicePath;
+
+  if (DevicePath == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  //
+  // We only use first byte of target identifer
+  //
+  TargetValue = *Target;
+
+  Dev = PVSCSI_FROM_PASS_THRU (This);
+  if (TargetValue > Dev->MaxTarget || Lun > Dev->MaxLun) {
+    return EFI_NOT_FOUND;
+  }
+
+  ScsiDevicePath = AllocatePool (sizeof (*ScsiDevicePath));
+  if (ScsiDevicePath == NULL) {
+    return EFI_OUT_OF_RESOURCES;
+  }
+
+  ScsiDevicePath->Header.Type      = MESSAGING_DEVICE_PATH;
+  ScsiDevicePath->Header.SubType   = MSG_SCSI_DP;
+  ScsiDevicePath->Header.Length[0] = (UINT8)sizeof (*ScsiDevicePath);
+  ScsiDevicePath->Header.Length[1] = (UINT8)(sizeof (*ScsiDevicePath) >> 8);
+  ScsiDevicePath->Pun              = TargetValue;
+  ScsiDevicePath->Lun              = (UINT16)Lun;
+
+  *DevicePath = &ScsiDevicePath->Header;
+  return EFI_SUCCESS;
 }
 
 STATIC
@@ -150,7 +181,33 @@ PvScsiGetTargetLun (
   OUT UINT64                                        *Lun
   )
 {
-  return EFI_UNSUPPORTED;
+  SCSI_DEVICE_PATH *ScsiDevicePath;
+  PVSCSI_DEV       *Dev;
+
+  if (DevicePath == NULL || Target == NULL || *Target == NULL || Lun == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  if (DevicePath->Type    != MESSAGING_DEVICE_PATH ||
+      DevicePath->SubType != MSG_SCSI_DP) {
+    return EFI_UNSUPPORTED;
+  }
+
+  ScsiDevicePath = (SCSI_DEVICE_PATH *)DevicePath;
+  Dev = PVSCSI_FROM_PASS_THRU (This);
+  if (ScsiDevicePath->Pun > Dev->MaxTarget ||
+      ScsiDevicePath->Lun > Dev->MaxLun) {
+    return EFI_NOT_FOUND;
+  }
+
+  //
+  // We only use first byte of target identifer
+  //
+  **Target = (UINT8)ScsiDevicePath->Pun;
+  ZeroMem (*Target + 1, TARGET_MAX_BYTES - 1);
+  *Lun = ScsiDevicePath->Lun;
+
+  return EFI_SUCCESS;
 }
 
 STATIC
-- 
2.20.1