Re: [edk2-devel] [PATCH v4 07/13] OvmfPkg/MptScsiDxe: Build and decode DevicePath

["Laszlo Ersek" <lersek@redhat.com>]

On 04/14/20 19:38, Nikita Leshenko wrote:
> Used to identify the individual disks in the hardware tree.
> 
> Currently we accept only Pun=0 and Lun=0, but we will relax this in a
> later patch.
> 
> Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=2390
> Signed-off-by: Nikita Leshenko <nikita.leshchenko@oracle.com>
> Reviewed-by: Liran Alon <liran.alon@oracle.com>
> ---
>  OvmfPkg/MptScsiDxe/MptScsi.c | 57 ++++++++++++++++++++++++++++++++++--
>  1 file changed, 55 insertions(+), 2 deletions(-)
> 
> diff --git a/OvmfPkg/MptScsiDxe/MptScsi.c b/OvmfPkg/MptScsiDxe/MptScsi.c
> index 30fb084379db..69ab947c0da2 100644
> --- a/OvmfPkg/MptScsiDxe/MptScsi.c
> +++ b/OvmfPkg/MptScsiDxe/MptScsi.c
> @@ -126,7 +126,34 @@ MptScsiBuildDevicePath (
>    IN OUT EFI_DEVICE_PATH_PROTOCOL                  **DevicePath
>    )
>  {
> -  return EFI_UNSUPPORTED;
> +  SCSI_DEVICE_PATH *ScsiDevicePath;
> +
> +  if (DevicePath == NULL) {
> +    return EFI_INVALID_PARAMETER;
> +  }
> +
> +  //
> +  // This device support 256 targets only, so it's enough to dereference
> +  // the LSB of Target.
> +  //
> +  if (*Target > 0 || Lun > 0) {
> +    return EFI_NOT_FOUND;
> +  }
> +
> +  ScsiDevicePath = AllocateZeroPool (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              = *Target;
> +  ScsiDevicePath->Lun              = (UINT16)Lun;
> +
> +  *DevicePath = &ScsiDevicePath->Header;
> +  return EFI_SUCCESS;
>  }
>  
>  STATIC
> @@ -139,7 +166,33 @@ MptScsiGetTargetLun (
>    OUT UINT64                                       *Lun
>    )
>  {
> -  return EFI_UNSUPPORTED;
> +  SCSI_DEVICE_PATH *ScsiDevicePath;
> +
> +  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;
> +  if (ScsiDevicePath->Pun > 0 ||
> +      ScsiDevicePath->Lun > 0) {
> +    return EFI_NOT_FOUND;
> +  }
> +
> +  ZeroMem (*Target, TARGET_MAX_BYTES);
> +  //
> +  // This device support 256 targets only, so it's enough to set the LSB
> +  // of Target.
> +  //
> +  **Target = (UINT8)ScsiDevicePath->Pun;
> +  *Lun = ScsiDevicePath->Lun;
> +
> +  return EFI_SUCCESS;
>  }
>  
>  STATIC
> 

Reviewed-by: Laszlo Ersek <lersek@redhat.com>