OvmfPkg: Update AcpiPlatformDxe to alter MADT table

RFC: https://bugzilla.tianocore.org/show_bug.cgi?id=3429

In TDX the guest firmware is designed to publish a multiprocessor-wakeup
structure to let the guest-bootstrap processor wake up guest-application
processors with a mailbox. The mailbox is memory that the guest firmware
can reserve so each guest virtual processor can have the guest OS send
a message to them. The address of the mailbox is recorded in the MADT
table. See [ACPI].

To maintain the simplicity of the AcpiPlatformDxe, the MADT ACPI table
will be altered in another driver (TdxDxe) by installing a protocol
to notify that the ACPI table provided by Qemu is ready. Then in TdxDxe
a notification functioin will be called to alter the MADT table to recorded
the mailbox address.

The protocol is gQemuAcpiTableNotifyProtocolGuid.

Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Erdem Aktas <erdemaktas@google.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
Signed-off-by: Min Xu <min.m.xu@intel.com>

3 files changed, 41 insertions, 1 deletions

diff --git a/OvmfPkg/AcpiPlatformDxe/AcpiPlatformDxe.inf b/OvmfPkg/AcpiPlatformDxe/AcpiPlatformDxe.inf
index f22bd7cb6d..09daf30bcd 100644
--- a/OvmfPkg/AcpiPlatformDxe/AcpiPlatformDxe.inf
+++ b/OvmfPkg/AcpiPlatformDxe/AcpiPlatformDxe.inf
@@ -49,6 +49,7 @@
 [Protocols]

   gEfiAcpiTableProtocolGuid                     # PROTOCOL ALWAYS_CONSUMED

   gEfiPciIoProtocolGuid                         # PROTOCOL SOMETIMES_CONSUMED

+  gQemuAcpiTableNotifyProtocolGuid              # PROTOCOL PRODUCES

 

 [Guids]

   gRootBridgesConnectedEventGroupGuid

diff --git a/OvmfPkg/AcpiPlatformDxe/QemuFwCfgAcpi.c b/OvmfPkg/AcpiPlatformDxe/QemuFwCfgAcpi.c
index b885965a60..c8dee17c13 100644
--- a/OvmfPkg/AcpiPlatformDxe/QemuFwCfgAcpi.c
+++ b/OvmfPkg/AcpiPlatformDxe/QemuFwCfgAcpi.c
@@ -19,7 +19,10 @@
 #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;

 

 //

 // The user structure for the ordered collection that will track the fw_cfg

@@ -1273,7 +1276,16 @@ UninstallAcpiTables:
       AcpiProtocol->UninstallAcpiTable (AcpiProtocol, InstalledKey[Installed]);

     }

   } else {

-    DEBUG ((DEBUG_INFO, "%a: installed %d tables\n", __FUNCTION__, Installed));

+    //

+    // Install a protocol to notify that the ACPI table provided by Qemu is

+    // ready.

+    //

+    gBS->InstallProtocolInterface (

+           &mQemuAcpiHandle,

+           &gQemuAcpiTableNotifyProtocolGuid,

+           EFI_NATIVE_INTERFACE,

+           &mAcpiNotifyProtocol

+           );

   }

 

   for (SeenPointerEntry = OrderedCollectionMin (SeenPointers);

diff --git a/OvmfPkg/Include/Protocol/QemuAcpiTableNotify.h b/OvmfPkg/Include/Protocol/QemuAcpiTableNotify.h
new file mode 100644
index 0000000000..a3dd2fc1dc
--- /dev/null
+++ b/OvmfPkg/Include/Protocol/QemuAcpiTableNotify.h
@@ -0,0 +1,27 @@
+/** @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