OvmfPkg: Introduce XenPlatformPei

Introduce XenPlatformPei, a copy of OvmfPkg/PlatformPei without some
of QEMU specific initialization, Xen does not support QemuFwCfg.

This new module will be adjusted to accommodate Xen PVH.

fw_cfg dependents that have been removed, which are dynamically skipped
when running PlatformPei on Xen:
- GetFirstNonAddress(): controlling the 64-bit PCI MMIO aperture via the
(experimental) "opt/ovmf/X-PciMmio64Mb" file
- GetFirstNonAddress(): honoring the hotplug DIMM area
("etc/reserved-memory-end") in the placement of the 64-bit PCI MMIO
aperture
- NoexecDxeInitialization() is removed, so PcdPropertiesTableEnable and
PcdSetNxForStack are left constant FALSE (not set dynamically from
fw_cfg "opt/ovmf/PcdXxxx")
- MaxCpuCountInitialization(), PublishPeiMemory(): the max CPU count is
not taken from the QemuFwCfgItemSmpCpuCount fw_cfg key;
PcdCpuMaxLogicalProcessorNumber is used intact and
PcdCpuApInitTimeOutInMicroSeconds is never changed or used.
- InitializeXenPlatform(), S3Verification(): S3 is assumed disabled (not
consulting "etc/system-states" via QemuFwCfgS3Enabled()).
- InstallFeatureControlCallback(): the feature control MSR is not set
from "etc/msr_feature_control"
(also removed FeatureControl.c as there is nothing been executed)

Also removed:
- SMRAM/TSEG-related low mem size adjusting (PcdSmmSmramRequire is
assumed FALSE) in PublishPeiMemory(),
- QemuInitializeRam() entirely,

Xen related changes:
- Have removed the module variable mXen, as it should be always true.
- Have the platform PEI initialization fails if Xen has not been
  detected.

Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=1689
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20190813113119.14804-5-anthony.perard@citrix.com>

OvmfPkg/XenPlatformPei/Fv.c

@@ -0,0 +1,76 @@
+/** @file
+  Build FV related hobs for platform.
+
+  Copyright (c) 2006 - 2013, Intel Corporation. All rights reserved.<BR>
+  Copyright (c) 2019, Citrix Systems, Inc.
+
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include "PiPei.h"
+#include "Platform.h"
+#include <Library/DebugLib.h>
+#include <Library/HobLib.h>
+#include <Library/PeiServicesLib.h>
+#include <Library/PcdLib.h>
+
+
+/**
+  Publish PEI & DXE (Decompressed) Memory based FVs to let PEI
+  and DXE know about them.
+
+  @retval EFI_SUCCESS   Platform PEI FVs were initialized successfully.
+
+**/
+EFI_STATUS
+PeiFvInitialization (
+  VOID
+  )
+{
+  DEBUG ((DEBUG_INFO, "Platform PEI Firmware Volume Initialization\n"));
+
+  //
+  // Create a memory allocation HOB for the PEI FV.
+  //
+  // Allocate as ACPI NVS is S3 is supported
+  //
+  BuildMemoryAllocationHob (
+    PcdGet32 (PcdOvmfPeiMemFvBase),
+    PcdGet32 (PcdOvmfPeiMemFvSize),
+    EfiBootServicesData
+    );
+
+  //
+  // Let DXE know about the DXE FV
+  //
+  BuildFvHob (PcdGet32 (PcdOvmfDxeMemFvBase), PcdGet32 (PcdOvmfDxeMemFvSize));
+
+  //
+  // Create a memory allocation HOB for the DXE FV.
+  //
+  // If "secure" S3 is needed, then SEC will decompress both PEI and DXE
+  // firmware volumes at S3 resume too, hence we need to keep away the OS from
+  // DXEFV as well. Otherwise we only need to keep away DXE itself from the
+  // DXEFV area.
+  //
+  BuildMemoryAllocationHob (
+    PcdGet32 (PcdOvmfDxeMemFvBase),
+    PcdGet32 (PcdOvmfDxeMemFvSize),
+    EfiBootServicesData
+    );
+
+  //
+  // Let PEI know about the DXE FV so it can find the DXE Core
+  //
+  PeiServicesInstallFvInfoPpi (
+    NULL,
+    (VOID *)(UINTN) PcdGet32 (PcdOvmfDxeMemFvBase),
+    PcdGet32 (PcdOvmfDxeMemFvSize),
+    NULL,
+    NULL
+    );
+
+  return EFI_SUCCESS;
+}
+