OvmfPkg/MptScsiDxe: Report targets and one LUN

The controller supports up to 8 targets in practice (Not reported by the
controller, but based on the implementation of the virtual device),
report them in GetNextTarget and GetNextTargetLun. The firmware will
then try to communicate with them and create a block device for each one
that responds.

Support for multiple LUNs will be implemented in another series.

Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=2390
Signed-off-by: Nikita Leshenko <nikita.leshchenko@oracle.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20200504210607.144434-7-nikita.leshchenko@oracle.com>

OvmfPkg/MptScsiDxe/MptScsi.c

@@ -11,8 +11,10 @@
 
 #include <IndustryStandard/FusionMptScsi.h>
 #include <IndustryStandard/Pci.h>
+#include <Library/BaseMemoryLib.h>
 #include <Library/DebugLib.h>
 #include <Library/MemoryAllocationLib.h>
+#include <Library/PcdLib.h>
 #include <Library/UefiBootServicesTableLib.h>
 #include <Library/UefiLib.h>
 #include <Protocol/PciIo.h>
@@ -34,6 +36,7 @@ typedef struct {
   UINT32                          Signature;
   EFI_EXT_SCSI_PASS_THRU_PROTOCOL PassThru;
   EFI_EXT_SCSI_PASS_THRU_MODE     PassThruMode;
+  UINT8                           MaxTarget;
 } MPT_SCSI_DEV;
 
 #define MPT_SCSI_FROM_PASS_THRU(PassThruPtr) \
@@ -57,6 +60,22 @@ MptScsiPassThru (
   return EFI_UNSUPPORTED;
 }
 
+STATIC
+BOOLEAN
+IsTargetInitialized (
+  IN UINT8                                          *Target
+  )
+{
+  UINTN Idx;
+
+  for (Idx = 0; Idx < TARGET_MAX_BYTES; ++Idx) {
+    if (Target[Idx] != 0xFF) {
+      return TRUE;
+    }
+  }
+  return FALSE;
+}
+
 STATIC
 EFI_STATUS
 EFIAPI
@@ -66,7 +85,28 @@ MptScsiGetNextTargetLun (
   IN OUT UINT64                                     *Lun
   )
 {
-  return EFI_UNSUPPORTED;
+  MPT_SCSI_DEV *Dev;
+
+  Dev = MPT_SCSI_FROM_PASS_THRU (This);
+  //
+  // Currently support only LUN 0, so hardcode it
+  //
+  if (!IsTargetInitialized (*Target)) {
+    ZeroMem (*Target, TARGET_MAX_BYTES);
+    *Lun = 0;
+  } else if (**Target > Dev->MaxTarget || *Lun > 0) {
+    return EFI_INVALID_PARAMETER;
+  } else if (**Target < Dev->MaxTarget) {
+    //
+    // This device interface support 256 targets only, so it's enough to
+    // increment the LSB of Target, as it will never overflow.
+    //
+    **Target += 1;
+  } else {
+    return EFI_NOT_FOUND;
+  }
+
+  return EFI_SUCCESS;
 }
 
 STATIC
@@ -77,7 +117,24 @@ MptScsiGetNextTarget (
   IN OUT UINT8                                     **Target
   )
 {
-  return EFI_UNSUPPORTED;
+  MPT_SCSI_DEV *Dev;
+
+  Dev = MPT_SCSI_FROM_PASS_THRU (This);
+  if (!IsTargetInitialized (*Target)) {
+    ZeroMem (*Target, TARGET_MAX_BYTES);
+  } else if (**Target > Dev->MaxTarget) {
+    return EFI_INVALID_PARAMETER;
+  } else if (**Target < Dev->MaxTarget) {
+    //
+    // This device interface support 256 targets only, so it's enough to
+    // increment the LSB of Target, as it will never overflow.
+    //
+    **Target += 1;
+  } else {
+    return EFI_NOT_FOUND;
+  }
+
+  return EFI_SUCCESS;
 }
 
 STATIC
@@ -206,6 +263,8 @@ MptScsiControllerStart (
 
   Dev->Signature = MPT_SCSI_DEV_SIGNATURE;
 
+  Dev->MaxTarget = PcdGet8 (PcdMptScsiMaxTargetLimit);
+
   //
   // Host adapter channel, doesn't exist
   //

OvmfPkg/MptScsiDxe/MptScsiDxe.inf

@@ -24,8 +24,10 @@
   OvmfPkg/OvmfPkg.dec
 
 [LibraryClasses]
+  BaseMemoryLib
   DebugLib
   MemoryAllocationLib
+  PcdLib
   UefiBootServicesTableLib
   UefiDriverEntryPoint
   UefiLib
@@ -33,3 +35,6 @@
 [Protocols]
   gEfiExtScsiPassThruProtocolGuid        ## BY_START
   gEfiPciIoProtocolGuid                  ## TO_START
+
+[FixedPcd]
+  gUefiOvmfPkgTokenSpaceGuid.PcdMptScsiMaxTargetLimit   ## CONSUMES

OvmfPkg/OvmfPkg.dec

@@ -167,6 +167,10 @@
   #  polling loop iteration.
   gUefiOvmfPkgTokenSpaceGuid.PcdPvScsiWaitForCmpStallInUsecs|5|UINT32|0x38
 
+  ## Set the *inclusive* number of targets that MptScsi exposes for scan
+  #  by ScsiBusDxe.
+  gUefiOvmfPkgTokenSpaceGuid.PcdMptScsiMaxTargetLimit|7|UINT8|0x39
+
   gUefiOvmfPkgTokenSpaceGuid.PcdOvmfFlashNvStorageEventLogBase|0x0|UINT32|0x8
   gUefiOvmfPkgTokenSpaceGuid.PcdOvmfFlashNvStorageEventLogSize|0x0|UINT32|0x9
   gUefiOvmfPkgTokenSpaceGuid.PcdOvmfFirmwareFdSize|0x0|UINT32|0xa