Re: [edk2-devel] [PATCH V2 1/6] OvmfPkg/AcpiPlatformDxe: Remove QEMU_ACPI_TABLE_NOTIFY_PROTOCOL

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

On 1/9/23 14:59, Min Xu wrote:
> From: Min M Xu <min.m.xu@intel.com>
> 
> BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=4237
> 
> The QEMU_ACPI_TABLE_NOTIFY_PROTOCOL structure is superfluous because NULL
> protocol interfaces have been used in edk2 repeatedly. A protocol instance
> can exist in the protocol database with a NULL associated interface.
> Therefore the QEMU_ACPI_TABLE_NOTIFY_PROTOCOL type, the
> "QemuAcpiTableNotify.h" header, and the "mAcpiNotifyProtocol" global
> variable can be removed.
> 
> Cc: Laszlo Ersek <lersek@redhat.com>
> Cc: Erdem Aktas <erdemaktas@google.com>
> Cc: James Bottomley <jejb@linux.ibm.com>
> Cc: Jiewen Yao <jiewen.yao@intel.com>
> Cc: Gerd Hoffmann <kraxel@redhat.com>
> Cc: Tom Lendacky <thomas.lendacky@amd.com>
> Cc: Sebastien Boeuf <sebastien.boeuf@intel.com>
> Reported-by: Laszlo Ersek <lersek@redhat.com>
> Signed-off-by: Min Xu <min.m.xu@intel.com>
> ---
>  OvmfPkg/AcpiPlatformDxe/CloudHvAcpi.c         |  7 ++---
>  OvmfPkg/AcpiPlatformDxe/QemuFwCfgAcpi.c       |  6 ++---
>  .../Include/Protocol/QemuAcpiTableNotify.h    | 27 -------------------
>  3 files changed, 4 insertions(+), 36 deletions(-)
>  delete mode 100644 OvmfPkg/Include/Protocol/QemuAcpiTableNotify.h
> 
> diff --git a/OvmfPkg/AcpiPlatformDxe/CloudHvAcpi.c b/OvmfPkg/AcpiPlatformDxe/CloudHvAcpi.c
> index cbe8bb9b0c75..ad39e4253478 100644
> --- a/OvmfPkg/AcpiPlatformDxe/CloudHvAcpi.c
> +++ b/OvmfPkg/AcpiPlatformDxe/CloudHvAcpi.c
> @@ -15,15 +15,12 @@
>  #include <Library/PcdLib.h>                               // PcdGet32()
>  #include <Library/HobLib.h>                               // GetFirstGuidHob(), GetNextGuidHob()
>  #include <Library/UefiBootServicesTableLib.h>             // gBS
> -
>  #include <Protocol/AcpiSystemDescriptionTable.h>
>  #include <Protocol/AcpiTable.h>
> -#include <Protocol/QemuAcpiTableNotify.h>                 // QEMU_ACPI_TABLE_NOTIFY_PROTOCOL
>  
>  #include "AcpiPlatform.h"
>  
> -EFI_HANDLE                       mChAcpiHandle = NULL;
> -QEMU_ACPI_TABLE_NOTIFY_PROTOCOL  mChAcpiNotifyProtocol;
> +EFI_HANDLE  mChAcpiHandle = NULL;
>  
>  EFI_STATUS
>  EFIAPI
> @@ -96,7 +93,7 @@ InstallCloudHvTablesTdx (
>           &mChAcpiHandle,
>           &gQemuAcpiTableNotifyProtocolGuid,
>           EFI_NATIVE_INTERFACE,
> -         &mChAcpiNotifyProtocol
> +         NULL
>           );
>  
>    return EFI_SUCCESS;
> diff --git a/OvmfPkg/AcpiPlatformDxe/QemuFwCfgAcpi.c b/OvmfPkg/AcpiPlatformDxe/QemuFwCfgAcpi.c
> index c8dee17c13e6..1a3852904df9 100644
> --- a/OvmfPkg/AcpiPlatformDxe/QemuFwCfgAcpi.c
> +++ b/OvmfPkg/AcpiPlatformDxe/QemuFwCfgAcpi.c
> @@ -19,10 +19,8 @@
>  #include <Library/QemuFwCfgS3Lib.h>           // QemuFwCfgS3Enabled()
>  #include <Library/UefiBootServicesTableLib.h> // gBS
>  
> -#include <Protocol/QemuAcpiTableNotify.h>
>  #include "AcpiPlatform.h"
> -EFI_HANDLE                       mQemuAcpiHandle = NULL;
> -QEMU_ACPI_TABLE_NOTIFY_PROTOCOL  mAcpiNotifyProtocol;
> +EFI_HANDLE  mQemuAcpiHandle = NULL;
>  
>  //
>  // The user structure for the ordered collection that will track the fw_cfg
> @@ -1284,7 +1282,7 @@ UninstallAcpiTables:
>             &mQemuAcpiHandle,
>             &gQemuAcpiTableNotifyProtocolGuid,
>             EFI_NATIVE_INTERFACE,
> -           &mAcpiNotifyProtocol
> +           NULL
>             );
>    }
>  
> diff --git a/OvmfPkg/Include/Protocol/QemuAcpiTableNotify.h b/OvmfPkg/Include/Protocol/QemuAcpiTableNotify.h
> deleted file mode 100644
> index a3dd2fc1dc91..000000000000
> --- a/OvmfPkg/Include/Protocol/QemuAcpiTableNotify.h
> +++ /dev/null
> @@ -1,27 +0,0 @@
> -/** @file
> -
> -  SPDX-License-Identifier: BSD-2-Clause-Patent
> -
> -**/
> -
> -#ifndef QEMU_ACPI_TABLE_NOTIFY_H_
> -#define QEMU_ACPI_TABLE_NOTIFY_H_
> -
> -#define QEMU_ACPI_TABLE_NOTIFY_GUID \
> -  { 0x928939b2, 0x4235, 0x462f, { 0x95, 0x80, 0xf6, 0xa2, 0xb2, 0xc2, 0x1a, 0x4f } };
> -
> -///
> -/// Forward declaration
> -///
> -typedef struct _QEMU_ACPI_TABLE_NOTIFY_PROTOCOL QEMU_ACPI_TABLE_NOTIFY_PROTOCOL;
> -
> -///
> -/// Protocol structure
> -///
> -struct _QEMU_ACPI_TABLE_NOTIFY_PROTOCOL {
> -  UINT8    Notify;
> -};
> -
> -extern EFI_GUID  gQemuAcpiTableNotifyProtocolGuid;
> -
> -#endif

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