Re: [PATCH v3 04/15] ArmVirtPkg: Add kvmtool platform driver

["Ard Biesheuvel" <ard.biesheuvel@arm.com>]

On 6/24/20 3:34 PM, Sami Mujawar wrote:
> Kvmtool is a virtual machine manager that enables
> hosting KVM guests. It essentially provides a
> virtual hardware platform for guest operating
> systems.
> 
> Kvmtool hands of a device tree containing the
> current hardware configuration to the firmware.
> 
> A standards-based operating system would use
> ACPI to consume the platform hardware
> information, while some operating systems may
> prefer to use Device Tree.
> 
> The KvmtoolPlatformDxe performs the platform
> actions like determining if the firmware should
> expose ACPI or the Device Tree based hardware
> description to the operating system.
> 
> Signed-off-by: Sami Mujawar <sami.mujawar@arm.com>
> Acked-by: Laszlo Ersek <lersek@redhat.com>
> ---
> 
> Notes:
>      v3:
>        - Don't use CpuDeadLoop()s in your drivers.                 [Ard]
>        - Returned error code instead of dead loop.                 [Sami]
>        - Installing a protocol on an image handle should not       [Ard]
>          ever fail. So just use ASSERT_EFI_ERROR().
>        - Added assert and returned status code.                    [Sami]
>          Ref: https://edk2.groups.io/g/devel/topic/74200911#59650
>      
>      v2:
>        - Updated according to review comments.                     [Sami]
>      
>      v1:
>        - Add kvmtool platform driver to support loading platform   [Sami]
>          specific information.
>        - Keep code to initialise the variable storage PCDs in the  [Laszlo]
>          platform-specific FVB driver.
>        - Document code derived from                                [Laszlo]
>          "ArmVirtPkg/PlatformHasAcpiDtDxe"
>          Ref: https://edk2.groups.io/g/devel/topic/30915278#30757
> 
>   ArmVirtPkg/KvmtoolPlatformDxe/KvmtoolPlatformDxe.c   | 85 ++++++++++++++++++++
>   ArmVirtPkg/KvmtoolPlatformDxe/KvmtoolPlatformDxe.inf | 47 +++++++++++
>   2 files changed, 132 insertions(+)
> 
> diff --git a/ArmVirtPkg/KvmtoolPlatformDxe/KvmtoolPlatformDxe.c b/ArmVirtPkg/KvmtoolPlatformDxe/KvmtoolPlatformDxe.c
> new file mode 100644
> index 0000000000000000000000000000000000000000..17a65bdff0c1a5851e45c2a9ede97f76236502e3
> --- /dev/null
> +++ b/ArmVirtPkg/KvmtoolPlatformDxe/KvmtoolPlatformDxe.c
> @@ -0,0 +1,85 @@
> +/** @file
> +
> +  The KvmtoolPlatformDxe performs the platform specific initialization like:
> +  - It decides if the firmware should expose ACPI or Device Tree-based
> +    hardware description to the operating system.
> +
> +  Copyright (c) 2018 - 2020, ARM Limited. All rights reserved.
> +
> +  SPDX-License-Identifier: BSD-2-Clause-Patent
> +
> +**/
> +
> +#include <Guid/VariableFormat.h>
> +#include <Library/BaseLib.h>
> +#include <Library/BaseMemoryLib.h>
> +#include <Library/DebugLib.h>
> +#include <Library/DxeServicesTableLib.h>

You are missing MemoryAllocationLib here - either add it here, or remove 
it from LibraryClasses

> +#include <Library/UefiBootServicesTableLib.h>
> +#include <Library/UefiDriverEntryPoint.h>
> +#include <Protocol/FdtClient.h>
> +
> +/** Decide if the firmware should expose ACPI tables or Device Tree and
> +    install the appropriate protocol interface.
> +
> +  Note: This function is derived from "ArmVirtPkg/PlatformHasAcpiDtDxe",
> +        by dropping the word size check, and the fw_cfg check.
> +
> +  @param [in]  ImageHandle  Handle for this image.
> +
> +  @retval EFI_SUCCESS             Success.
> +  @retval EFI_OUT_OF_RESOURCES    There was not enough memory to install the
> +                                  protocols.
> +  @retval EFI_INVALID_PARAMETER   A parameter is invalid.
> +
> +**/
> +STATIC
> +EFI_STATUS
> +PlatformHasAcpiDt (
> +  IN EFI_HANDLE           ImageHandle
> +  )
> +{
> +  if (!PcdGetBool (PcdForceNoAcpi)) {
> +    // Expose ACPI tables
> +    return gBS->InstallProtocolInterface (
> +                  &ImageHandle,
> +                  &gEdkiiPlatformHasAcpiGuid,
> +                  EFI_NATIVE_INTERFACE,
> +                  NULL
> +                  );
> +  }
> +
> +  // Expose the Device Tree.
> +  return gBS->InstallProtocolInterface (
> +                &ImageHandle,
> +                &gEdkiiPlatformHasDeviceTreeGuid,
> +                EFI_NATIVE_INTERFACE,
> +                NULL
> +                );
> +}
> +
> +/** Entry point for Kvmtool Platform Dxe
> +
> +  @param [in]  ImageHandle  Handle for this image.
> +  @param [in]  SystemTable  Pointer to the EFI system table.
> +
> +  @retval EFI_SUCCESS             Success.
> +  @retval EFI_OUT_OF_RESOURCES    There was not enough memory to install the
> +                                  protocols.
> +  @retval EFI_INVALID_PARAMETER   A parameter is invalid.
> +
> +**/
> +EFI_STATUS
> +EFIAPI
> +KvmtoolPlatformDxeEntryPoint (
> +  IN EFI_HANDLE           ImageHandle,
> +  IN EFI_SYSTEM_TABLE     *SystemTable
> +  )
> +{
> +  EFI_STATUS                     Status;
> +
> +  Status = PlatformHasAcpiDt (ImageHandle);
> +  ASSERT_EFI_ERROR (Status);
> +
> +  return Status;
> +}
> diff --git a/ArmVirtPkg/KvmtoolPlatformDxe/KvmtoolPlatformDxe.inf b/ArmVirtPkg/KvmtoolPlatformDxe/KvmtoolPlatformDxe.inf
> new file mode 100644
> index 0000000000000000000000000000000000000000..08a0fe5ce14469133479046385bdd48c22698639
> --- /dev/null
> +++ b/ArmVirtPkg/KvmtoolPlatformDxe/KvmtoolPlatformDxe.inf
> @@ -0,0 +1,47 @@
> +#/** @file
> +#
> +#  The KvmtoolPlatformDxe performs the platform specific initialization like:
> +#  - It decides if the firmware should expose ACPI or Device Tree-based
> +#    hardware description to the operating system.
> +#
> +#  Copyright (c) 2018 - 2020, ARM Limited. All rights reserved.
> +#
> +#  SPDX-License-Identifier: BSD-2-Clause-Patent
> +#
> +#**/
> +
> +[Defines]
> +  INF_VERSION                    = 0x0001001B
> +  BASE_NAME                      = KvmtoolPlatformDxe
> +  FILE_GUID                      = 7479CCCD-D721-442A-8C73-A72DBB886669
> +  MODULE_TYPE                    = DXE_DRIVER
> +  VERSION_STRING                 = 1.0
> +  ENTRY_POINT                    = KvmtoolPlatformDxeEntryPoint
> +
> +[Sources]
> +  KvmtoolPlatformDxe.c
> +
> +[Packages]
> +  ArmVirtPkg/ArmVirtPkg.dec
> +  EmbeddedPkg/EmbeddedPkg.dec
> +  MdePkg/MdePkg.dec
> +  MdeModulePkg/MdeModulePkg.dec
> +
> +[LibraryClasses]
> +  BaseLib
> +  BaseMemoryLib
> +  DebugLib
> +  DxeServicesTableLib
> +  MemoryAllocationLib
> +  UefiBootServicesTableLib
> +  UefiDriverEntryPoint
> +
> +[Guids]
> +  gEdkiiPlatformHasAcpiGuid       ## SOMETIMES_PRODUCES ## PROTOCOL
> +  gEdkiiPlatformHasDeviceTreeGuid ## SOMETIMES_PRODUCES ## PROTOCOL
> +
> +[Pcd]
> +  gArmVirtTokenSpaceGuid.PcdForceNoAcpi
> +
> +[Depex]
> +  TRUE
>