[PATCH 7/7] OvmfPkg: don't assign PCI BARs above 4GiB when CSM enabled

["David Woodhouse" <dwmw2@infradead.org>]

Mostly, this is only necessary for devices that the CSM might have
native support for, such as VirtIO and NVMe; PciBusDxe will already
degrade devices to 32-bit if they have an OpROM.

However, there doesn't seem to be a generic way of requesting PciBusDxe
to downgrade specific devices.

There's IncompatiblePciDeviceSupportProtocol but that doesn't provide
the PCI class information or a handle to the device itself, so there's
no simple way to just match on all NVMe devices, for example.

Just leave gUefiOvmfPkgTokenSpaceGuid.PcdPciMmio64Size set to zero for
CSM builds, until/unless that can be fixed.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
---
 OvmfPkg/OvmfPkgIa32X64.dsc | 2 ++
 OvmfPkg/OvmfPkgX64.dsc     | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/OvmfPkg/OvmfPkgIa32X64.dsc b/OvmfPkg/OvmfPkgIa32X64.dsc
index 639e33cb28..8fbe601386 100644
--- a/OvmfPkg/OvmfPkgIa32X64.dsc
+++ b/OvmfPkg/OvmfPkgIa32X64.dsc
@@ -542,8 +542,10 @@
   gUefiOvmfPkgTokenSpaceGuid.PcdPciIoSize|0x0
   gUefiOvmfPkgTokenSpaceGuid.PcdPciMmio32Base|0x0
   gUefiOvmfPkgTokenSpaceGuid.PcdPciMmio32Size|0x0
+!ifndef $(CSM_ENABLE)
   gUefiOvmfPkgTokenSpaceGuid.PcdPciMmio64Base|0x0
   gUefiOvmfPkgTokenSpaceGuid.PcdPciMmio64Size|0x800000000
+!endif
 
   gEfiMdePkgTokenSpaceGuid.PcdPlatformBootTimeOut|0
 
diff --git a/OvmfPkg/OvmfPkgX64.dsc b/OvmfPkg/OvmfPkgX64.dsc
index 69a3497c2c..6f15f11220 100644
--- a/OvmfPkg/OvmfPkgX64.dsc
+++ b/OvmfPkg/OvmfPkgX64.dsc
@@ -541,8 +541,10 @@
   gUefiOvmfPkgTokenSpaceGuid.PcdPciIoSize|0x0
   gUefiOvmfPkgTokenSpaceGuid.PcdPciMmio32Base|0x0
   gUefiOvmfPkgTokenSpaceGuid.PcdPciMmio32Size|0x0
+!ifndef $(CSM_ENABLE)
   gUefiOvmfPkgTokenSpaceGuid.PcdPciMmio64Base|0x0
   gUefiOvmfPkgTokenSpaceGuid.PcdPciMmio64Size|0x800000000
+!endif
 
   gEfiMdePkgTokenSpaceGuid.PcdPlatformBootTimeOut|0
 
-- 
2.21.0