From ebc201cd413d43382dbe4686a67fb7d704ed1e81 Mon Sep 17 00:00:00 2001
From: Sabin Rapan <sabrapan@amazon.com>
Date: Fri, 21 May 2021 10:27:48 +0300
Subject: [PATCH] uefi: Use PPI function mask for user confirmation

... that we got from fwcfg instead of duplicating the logic.
The function mask defines five values for each available function:
1. Not implemented (0)
2. Firmware only (1)
3. Blocked (2)
4. Allowed and requires user confirmation (3)
5. Allowed and does not require user confirmation (4)

Signed-off-by: Sabin Rapan <sabrapan@amazon.com>
Reviewed-by: Petre Eftime <epetre@amazon.com>
Reviewed-by: Laurentiu Stefan <stefala@amazon.com>

diff --git a/OvmfPkg/Include/IndustryStandard/QemuTpm.h b/OvmfPkg/Include/IndustryStandard/QemuTpm.h
index 1a269e6ad8..8bd8812a06 100644
--- a/OvmfPkg/Include/IndustryStandard/QemuTpm.h
+++ b/OvmfPkg/Include/IndustryStandard/QemuTpm.h
@@ -50,6 +50,7 @@ typedef struct {
   UINT32    PpiAddress;
   UINT8     TpmVersion;
   UINT8     PpiVersion;
+  UINT8     PpiSuppFunc[256];
 } QEMU_FWCFG_TPM_CONFIG;
 #pragma pack ()
 
diff --git a/OvmfPkg/Library/Tcg2PhysicalPresenceLibQemu/DxeTcg2PhysicalPresenceLib.c b/OvmfPkg/Library/Tcg2PhysicalPresenceLibQemu/DxeTcg2PhysicalPresenceLib.c
index 4038020251..33a3d40eb1 100644
--- a/OvmfPkg/Library/Tcg2PhysicalPresenceLibQemu/DxeTcg2PhysicalPresenceLib.c
+++ b/OvmfPkg/Library/Tcg2PhysicalPresenceLibQemu/DxeTcg2PhysicalPresenceLib.c
@@ -132,21 +132,13 @@ QemuTpmInitPPI (
     goto InvalidPpiAddress;
   }
 
-  for (Idx = 0; Idx < ARRAY_SIZE (mPpi->Func); Idx++) {
-    mPpi->Func[Idx] = 0;
+  if (ARRAY_SIZE (mPpi->Func) != ARRAY_SIZE (Config.PpiSuppFunc)) {
+    DEBUG ((DEBUG_ERROR, "[TPM2PP] mPpi and Config.PpiSuppFunc have different sizes (%d vs %d)\n", ARRAY_SIZE (mPpi->Func), ARRAY_SIZE (Config.PpiSuppFunc)));
+    goto InvalidPpiAddress;
   }
 
-  if (Config.TpmVersion == QEMU_TPM_VERSION_2) {
-    mPpi->Func[TCG2_PHYSICAL_PRESENCE_NO_ACTION]         = TPM_PPI_FLAGS;
-    mPpi->Func[TCG2_PHYSICAL_PRESENCE_CLEAR]             = TPM_PPI_FLAGS;
-    mPpi->Func[TCG2_PHYSICAL_PRESENCE_ENABLE_CLEAR]      = TPM_PPI_FLAGS;
-    mPpi->Func[TCG2_PHYSICAL_PRESENCE_ENABLE_CLEAR_2]    = TPM_PPI_FLAGS;
-    mPpi->Func[TCG2_PHYSICAL_PRESENCE_ENABLE_CLEAR_3]    = TPM_PPI_FLAGS;
-    mPpi->Func[TCG2_PHYSICAL_PRESENCE_SET_PCR_BANKS]     = TPM_PPI_FLAGS;
-    mPpi->Func[TCG2_PHYSICAL_PRESENCE_CHANGE_EPS]        = TPM_PPI_FLAGS;
-    mPpi->Func[TCG2_PHYSICAL_PRESENCE_LOG_ALL_DIGESTS]   = TPM_PPI_FLAGS;
-    mPpi->Func[TCG2_PHYSICAL_PRESENCE_ENABLE_BLOCK_SID]  = TPM_PPI_FLAGS;
-    mPpi->Func[TCG2_PHYSICAL_PRESENCE_DISABLE_BLOCK_SID] = TPM_PPI_FLAGS;
+  for (Idx = 0; Idx < ARRAY_SIZE (mPpi->Func); Idx++) {
+    mPpi->Func[Idx] = Config.PpiSuppFunc[Idx];
   }
 
   if (mPpi->In == 0) {
@@ -693,27 +685,9 @@ Tcg2HaveValidTpmRequest  (
     }
   }
 
-  switch (mPpi->Request) {
-    case TCG2_PHYSICAL_PRESENCE_NO_ACTION:
-    case TCG2_PHYSICAL_PRESENCE_LOG_ALL_DIGESTS:
+  if (mPpi->Request < ARRAY_SIZE(mPpi->Func)) {
+    if (mPpi->Func[mPpi->Request] == QEMU_TPM_PPI_FUNC_ALLOWED_USR_NOT_REQ)
       *RequestConfirmed = TRUE;
-      return TRUE;
-
-    case TCG2_PHYSICAL_PRESENCE_CLEAR:
-    case TCG2_PHYSICAL_PRESENCE_ENABLE_CLEAR:
-    case TCG2_PHYSICAL_PRESENCE_ENABLE_CLEAR_2:
-    case TCG2_PHYSICAL_PRESENCE_ENABLE_CLEAR_3:
-    case TCG2_PHYSICAL_PRESENCE_SET_PCR_BANKS:
-    case TCG2_PHYSICAL_PRESENCE_CHANGE_EPS:
-    case TCG2_PHYSICAL_PRESENCE_ENABLE_BLOCK_SID:
-    case TCG2_PHYSICAL_PRESENCE_DISABLE_BLOCK_SID:
-      break;
-
-    default:
-      //
-      // Wrong Physical Presence command
-      //
-      return FALSE;
   }
 
   //