[PATCH v2 2/3] OvmfPkg/PlatformInitLib: move mmconfig to 0xe0000000

["Gerd Hoffmann" <kraxel@redhat.com>]

Also swap the ordering of 32bit PCI MMIO window on q35, i.e. use the
room between end of low memory and the start of the mmconfig bar.

With a typical configuration on modern qemu with gigabyte-aligned memory
the MMIO window start at 0x8000000, sized 1532 MB.  In case there is
memory present above 0x80000000 the window will start at 0xc0000000
instead, with 512 MB size.

This depends on qemu commit 4a4418369d6d ("q35: fix mmconfig and
PCI0._CRS"), so it raises the bar for the lowest supported version
to qemu 4.1 (released Aug 2019).

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 OvmfPkg/AmdSev/AmdSevX64.dsc               |  2 +-
 OvmfPkg/IntelTdx/IntelTdxX64.dsc           |  2 +-
 OvmfPkg/OvmfPkgIa32.dsc                    |  2 +-
 OvmfPkg/OvmfPkgIa32X64.dsc                 |  2 +-
 OvmfPkg/OvmfPkgX64.dsc                     |  2 +-
 OvmfPkg/OvmfXen.dsc                        |  2 +-
 OvmfPkg/Library/PlatformInitLib/Platform.c | 10 +++++-----
 7 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/OvmfPkg/AmdSev/AmdSevX64.dsc b/OvmfPkg/AmdSev/AmdSevX64.dsc
index 1cebd6b4bcc2..e8481ba8cdf3 100644
--- a/OvmfPkg/AmdSev/AmdSevX64.dsc
+++ b/OvmfPkg/AmdSev/AmdSevX64.dsc
@@ -443,7 +443,7 @@ [PcdsFixedAtBuild]
   #
   # On Q35 machine types that QEMU intends to support in the long term, QEMU
   # never lets the RAM below 4 GB exceed 2816 MB.
-  gEfiMdePkgTokenSpaceGuid.PcdPciExpressBaseAddress|0xB0000000
+  gEfiMdePkgTokenSpaceGuid.PcdPciExpressBaseAddress|0xE0000000
 
 !if $(SOURCE_DEBUG_ENABLE) == TRUE
   gEfiSourceLevelDebugPkgTokenSpaceGuid.PcdDebugLoadImageMethod|0x2
diff --git a/OvmfPkg/IntelTdx/IntelTdxX64.dsc b/OvmfPkg/IntelTdx/IntelTdxX64.dsc
index 95b9594ddce0..6fea54bb0b6b 100644
--- a/OvmfPkg/IntelTdx/IntelTdxX64.dsc
+++ b/OvmfPkg/IntelTdx/IntelTdxX64.dsc
@@ -448,7 +448,7 @@ [PcdsFixedAtBuild]
   #
   # On Q35 machine types that QEMU intends to support in the long term, QEMU
   # never lets the RAM below 4 GB exceed 2816 MB.
-  gEfiMdePkgTokenSpaceGuid.PcdPciExpressBaseAddress|0xB0000000
+  gEfiMdePkgTokenSpaceGuid.PcdPciExpressBaseAddress|0xE0000000
 
   #
   # The NumberOfPages values below are ad-hoc. They are updated sporadically at
diff --git a/OvmfPkg/OvmfPkgIa32.dsc b/OvmfPkg/OvmfPkgIa32.dsc
index 22dc29330d2d..fff3e13151ad 100644
--- a/OvmfPkg/OvmfPkgIa32.dsc
+++ b/OvmfPkg/OvmfPkgIa32.dsc
@@ -560,7 +560,7 @@ [PcdsFixedAtBuild]
   #
   # On Q35 machine types that QEMU intends to support in the long term, QEMU
   # never lets the RAM below 4 GB exceed 2816 MB.
-  gEfiMdePkgTokenSpaceGuid.PcdPciExpressBaseAddress|0xB0000000
+  gEfiMdePkgTokenSpaceGuid.PcdPciExpressBaseAddress|0xE0000000
 
 !if $(SOURCE_DEBUG_ENABLE) == TRUE
   gEfiSourceLevelDebugPkgTokenSpaceGuid.PcdDebugLoadImageMethod|0x2
diff --git a/OvmfPkg/OvmfPkgIa32X64.dsc b/OvmfPkg/OvmfPkgIa32X64.dsc
index 6b539814bdb0..169b9b9c2beb 100644
--- a/OvmfPkg/OvmfPkgIa32X64.dsc
+++ b/OvmfPkg/OvmfPkgIa32X64.dsc
@@ -565,7 +565,7 @@ [PcdsFixedAtBuild]
   #
   # On Q35 machine types that QEMU intends to support in the long term, QEMU
   # never lets the RAM below 4 GB exceed 2816 MB.
-  gEfiMdePkgTokenSpaceGuid.PcdPciExpressBaseAddress|0xB0000000
+  gEfiMdePkgTokenSpaceGuid.PcdPciExpressBaseAddress|0xE0000000
 
 !if $(SOURCE_DEBUG_ENABLE) == TRUE
   gEfiSourceLevelDebugPkgTokenSpaceGuid.PcdDebugLoadImageMethod|0x2
diff --git a/OvmfPkg/OvmfPkgX64.dsc b/OvmfPkg/OvmfPkgX64.dsc
index e3c64456dfef..12b88b71ab7f 100644
--- a/OvmfPkg/OvmfPkgX64.dsc
+++ b/OvmfPkg/OvmfPkgX64.dsc
@@ -586,7 +586,7 @@ [PcdsFixedAtBuild]
   #
   # On Q35 machine types that QEMU intends to support in the long term, QEMU
   # never lets the RAM below 4 GB exceed 2816 MB.
-  gEfiMdePkgTokenSpaceGuid.PcdPciExpressBaseAddress|0xB0000000
+  gEfiMdePkgTokenSpaceGuid.PcdPciExpressBaseAddress|0xE0000000
 
 !if $(SOURCE_DEBUG_ENABLE) == TRUE
   gEfiSourceLevelDebugPkgTokenSpaceGuid.PcdDebugLoadImageMethod|0x2
diff --git a/OvmfPkg/OvmfXen.dsc b/OvmfPkg/OvmfXen.dsc
index c328987e8432..18144d9a6d94 100644
--- a/OvmfPkg/OvmfXen.dsc
+++ b/OvmfPkg/OvmfXen.dsc
@@ -434,7 +434,7 @@ [PcdsFixedAtBuild]
   #
   # On Q35 machine types that QEMU intends to support in the long term, QEMU
   # never lets the RAM below 4 GB exceed 2816 MB.
-  gEfiMdePkgTokenSpaceGuid.PcdPciExpressBaseAddress|0xB0000000
+  gEfiMdePkgTokenSpaceGuid.PcdPciExpressBaseAddress|0xE0000000
 
 !if $(SOURCE_DEBUG_ENABLE) == TRUE
   gEfiSourceLevelDebugPkgTokenSpaceGuid.PcdDebugLoadImageMethod|0x2
diff --git a/OvmfPkg/Library/PlatformInitLib/Platform.c b/OvmfPkg/Library/PlatformInitLib/Platform.c
index 678e8e329023..5cf8af825a2f 100644
--- a/OvmfPkg/Library/PlatformInitLib/Platform.c
+++ b/OvmfPkg/Library/PlatformInitLib/Platform.c
@@ -156,8 +156,8 @@ PlatformMemMapInitialization (
   // address       purpose   size
   // ------------  --------  -------------------------
   // max(top, 2g)  PCI MMIO  0xFC000000 - max(top, 2g)  (pc)
-  // 0xB0000000    MMCONFIG                     256 MB  (q35)
-  // 0xC0000000    PCI MMIO                     960 MB  (q35)
+  // max(top, 2g)  PCI MMIO  0xE0000000 - max(top, 2g)  (q35)
+  // 0xE0000000    MMCONFIG                     256 MB  (q35)
   // 0xFC000000    gap                           44 MB
   // 0xFEC00000    IO-APIC                        4 KB
   // 0xFEC01000    gap                         1020 KB
@@ -168,6 +168,7 @@ PlatformMemMapInitialization (
   // 0xFEE00000    LAPIC                          1 MB
   //
   PlatformGetSystemMemorySizeBelow4gb (PlatformInfoHob);
+  PciBase      = PlatformInfoHob->Uc32Base;
   PciExBarBase = 0;
   if (PlatformInfoHob->HostBridgeDevId == INTEL_Q35_MCH_DEVICE_ID) {
     //
@@ -177,13 +178,12 @@ PlatformMemMapInitialization (
     PciExBarBase = PcdGet64 (PcdPciExpressBaseAddress);
     ASSERT (PlatformInfoHob->LowMemory <= PciExBarBase);
     ASSERT (PciExBarBase <= MAX_UINT32 - SIZE_256MB);
-    PciBase = (UINT32)(PciExBarBase + SIZE_256MB);
+    PciSize = (UINT32)(PciExBarBase - PciBase);
   } else {
     ASSERT (PlatformInfoHob->LowMemory <= PlatformInfoHob->Uc32Base);
-    PciBase = PlatformInfoHob->Uc32Base;
+    PciSize = 0xFC000000 - PciBase;
   }
 
-  PciSize = 0xFC000000 - PciBase;
   PlatformAddIoMemoryBaseSizeHob (PciBase, PciSize);
 
   PlatformInfoHob->PcdPciMmio32Base = PciBase;
-- 
2.39.2