[PATCH v5 2/6] OvmfPkg/PciHostBridgeLib: Init PCI aperture to 0

[Heyi Guo <heyi.guo@linaro.org>]

Use ZeroMem to initialize all fields in temporary
PCI_ROOT_BRIDGE_APERTURE variables to zero. This is not mandatory but
is helpful for future extension: when we add new fields to
PCI_ROOT_BRIDGE_APERTURE and the default value of these fields can
safely be zero, this code will not suffer from an additional
change.

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Heyi Guo <heyi.guo@linaro.org>

Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Anthony Perard <anthony.perard@citrix.com>
Cc: Julien Grall <julien.grall@linaro.org>
Cc: Ruiyu Ni <ruiyu.ni@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---
 OvmfPkg/Library/PciHostBridgeLib/PciHostBridgeLib.c | 4 ++++
 OvmfPkg/Library/PciHostBridgeLib/XenSupport.c       | 5 +++++
 2 files changed, 9 insertions(+)

diff --git a/OvmfPkg/Library/PciHostBridgeLib/PciHostBridgeLib.c b/OvmfPkg/Library/PciHostBridgeLib/PciHostBridgeLib.c
index ff837035caff..4a650a4c6df9 100644
--- a/OvmfPkg/Library/PciHostBridgeLib/PciHostBridgeLib.c
+++ b/OvmfPkg/Library/PciHostBridgeLib/PciHostBridgeLib.c
@@ -217,6 +217,10 @@ PciHostBridgeGetRootBridges (
   PCI_ROOT_BRIDGE_APERTURE Mem;
   PCI_ROOT_BRIDGE_APERTURE MemAbove4G;
 
+  ZeroMem (&Io, sizeof (Io));
+  ZeroMem (&Mem, sizeof (Mem));
+  ZeroMem (&MemAbove4G, sizeof (MemAbove4G));
+
   if (PcdGetBool (PcdPciDisableBusEnumeration)) {
     return ScanForRootBridges (Count);
   }
diff --git a/OvmfPkg/Library/PciHostBridgeLib/XenSupport.c b/OvmfPkg/Library/PciHostBridgeLib/XenSupport.c
index 31c63ae19e0a..aaf101dfcb0e 100644
--- a/OvmfPkg/Library/PciHostBridgeLib/XenSupport.c
+++ b/OvmfPkg/Library/PciHostBridgeLib/XenSupport.c
@@ -193,6 +193,11 @@ ScanForRootBridges (
 
   *NumberOfRootBridges = 0;
   RootBridges = NULL;
+  ZeroMem (&Io, sizeof (Io));
+  ZeroMem (&Mem, sizeof (Mem));
+  ZeroMem (&MemAbove4G, sizeof (MemAbove4G));
+  ZeroMem (&PMem, sizeof (PMem));
+  ZeroMem (&PMemAbove4G, sizeof (PMemAbove4G));
 
   //
   // After scanning all the PCI devices on the PCI root bridge's primary bus,
-- 
2.7.4