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/Platform.h

@@ -0,0 +1,108 @@
+/** @file
+  Platform PEI module include file.
+
+  Copyright (c) 2006 - 2016, Intel Corporation. All rights reserved.<BR>
+  Copyright (c) 2019, Citrix Systems, Inc.
+
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#ifndef _PLATFORM_PEI_H_INCLUDED_
+#define _PLATFORM_PEI_H_INCLUDED_
+
+#include <IndustryStandard/E820.h>
+
+VOID
+AddIoMemoryBaseSizeHob (
+  EFI_PHYSICAL_ADDRESS        MemoryBase,
+  UINT64                      MemorySize
+  );
+
+VOID
+AddIoMemoryRangeHob (
+  EFI_PHYSICAL_ADDRESS        MemoryBase,
+  EFI_PHYSICAL_ADDRESS        MemoryLimit
+  );
+
+VOID
+AddMemoryBaseSizeHob (
+  EFI_PHYSICAL_ADDRESS        MemoryBase,
+  UINT64                      MemorySize
+  );
+
+VOID
+AddMemoryRangeHob (
+  EFI_PHYSICAL_ADDRESS        MemoryBase,
+  EFI_PHYSICAL_ADDRESS        MemoryLimit
+  );
+
+VOID
+AddReservedMemoryBaseSizeHob (
+  EFI_PHYSICAL_ADDRESS        MemoryBase,
+  UINT64                      MemorySize,
+  BOOLEAN                     Cacheable
+  );
+
+VOID
+AddressWidthInitialization (
+  VOID
+  );
+
+VOID
+Q35TsegMbytesInitialization (
+  VOID
+  );
+
+EFI_STATUS
+PublishPeiMemory (
+  VOID
+  );
+
+UINT32
+GetSystemMemorySizeBelow4gb (
+  VOID
+  );
+
+VOID
+InitializeRamRegions (
+  VOID
+  );
+
+EFI_STATUS
+PeiFvInitialization (
+  VOID
+  );
+
+VOID
+InstallClearCacheCallback (
+  VOID
+  );
+
+EFI_STATUS
+InitializeXen (
+  VOID
+  );
+
+BOOLEAN
+XenDetect (
+  VOID
+  );
+
+VOID
+AmdSevInitialize (
+  VOID
+  );
+
+VOID
+XenPublishRamRegions (
+  VOID
+  );
+
+extern EFI_BOOT_MODE mBootMode;
+
+extern UINT8 mPhysMemAddressWidth;
+
+extern UINT16 mHostBridgeDevId;
+
+#endif // _PLATFORM_PEI_H_INCLUDED_