OvmfPkg: Handle Cloud Hypervisor host bridge

Handle things differently when the detected host bridge matches the
Cloud Hypervisor PCI host bridge identifier.

Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>

OvmfPkg/PlatformPei/MemDetect.c

@@ -16,6 +16,7 @@ Module Name:
 #include <IndustryStandard/E820.h>
 #include <IndustryStandard/I440FxPiix4.h>
 #include <IndustryStandard/Q35MchIch9.h>
+#include <IndustryStandard/CloudHv.h>
 #include <PiPei.h>
 #include <Register/Intel/SmramSaveStateMap.h>
 
@@ -159,6 +160,12 @@ QemuUc32BaseInitialization (
     return;
   }
 
+  if (mHostBridgeDevId == CLOUDHV_DEVICE_ID) {
+    Uc32Size      = CLOUDHV_MMIO_HOLE_SIZE;
+    mQemuUc32Base = CLOUDHV_MMIO_HOLE_ADDRESS;
+    return;
+  }
+
   ASSERT (mHostBridgeDevId == INTEL_82441_DEVICE_ID);
   //
   // On i440fx, start with the [LowerMemorySize, 4GB) range. Make sure one
@@ -819,7 +826,7 @@ QemuInitializeRam (
   // practically any alignment, and we may not have enough variable MTRRs to
   // cover it exactly.
   //
-  if (IsMtrrSupported ()) {
+  if (IsMtrrSupported () && (mHostBridgeDevId != CLOUDHV_DEVICE_ID)) {
     MtrrGetAllMtrrs (&MtrrSettings);
 
     //