OvmfPkg/XenPlatformPei: Rework memory detection

When running as a Xen PVH guest, there is no CMOS to read the memory
size from.  Rework GetSystemMemorySize(Below|Above)4gb() so they can
work without CMOS by reading the e820 table.

Rework XenPublishRamRegions to also care for the reserved and ACPI
entry in the e820 table. The region that was added by InitializeXen()
isn't needed as that same entry is in the e820 table provided by
hvmloader.

MTRR settings aren't modified anymore, on HVM it's already done by
hvmloader, on PVH it is supposed to have sane default. MTRR will need
to be done properly but keeping what's already been done by programs
that have run before OVMF will do for now.

Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=1689
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20190813113119.14804-24-anthony.perard@citrix.com>

1 files changed, 55 insertions, 22 deletions

diff --git a/OvmfPkg/XenPlatformPei/Xen.c b/OvmfPkg/XenPlatformPei/Xen.c
index 72f6f37b46..c4506def9a 100644
--- a/OvmfPkg/XenPlatformPei/Xen.c
+++ b/OvmfPkg/XenPlatformPei/Xen.c
@@ -276,9 +276,14 @@ XenPublishRamRegions (
   VOID

   )

 {

-  EFI_E820_ENTRY64  *E820Map;

-  UINT32            E820EntriesCount;

-  EFI_STATUS        Status;

+  EFI_E820_ENTRY64      *E820Map;

+  UINT32                E820EntriesCount;

+  EFI_STATUS            Status;

+  EFI_E820_ENTRY64      *Entry;

+  UINTN                 Index;

+  UINT64                LapicBase;

+  UINT64                LapicEnd;

+

 

   DEBUG ((DEBUG_INFO, "Using memory map provided by Xen\n"));

 

@@ -287,26 +292,60 @@ XenPublishRamRegions (
   //

   E820EntriesCount = 0;

   Status = XenGetE820Map (&E820Map, &E820EntriesCount);

-

   ASSERT_EFI_ERROR (Status);

 

-  if (E820EntriesCount > 0) {

-    EFI_E820_ENTRY64 *Entry;

-    UINT32 Loop;

-

-    for (Loop = 0; Loop < E820EntriesCount; Loop++) {

-      Entry = E820Map + Loop;

+  LapicBase = PcdGet32 (PcdCpuLocalApicBaseAddress);

+  LapicEnd = LapicBase + SIZE_1MB;

+  AddIoMemoryRangeHob (LapicBase, LapicEnd);

+

+  for (Index = 0; Index < E820EntriesCount; Index++) {

+    UINT64 Base;

+    UINT64 End;

+    UINT64 ReservedBase;

+    UINT64 ReservedEnd;

+

+    Entry = &E820Map[Index];

+

+    //

+    // Round up the start address, and round down the end address.

+    //

+    Base = ALIGN_VALUE (Entry->BaseAddr, (UINT64)EFI_PAGE_SIZE);

+    End = (Entry->BaseAddr + Entry->Length) & ~(UINT64)EFI_PAGE_MASK;

+

+    switch (Entry->Type) {

+    case EfiAcpiAddressRangeMemory:

+      AddMemoryRangeHob (Base, End);

+      break;

+    case EfiAcpiAddressRangeACPI:

+      AddReservedMemoryRangeHob (Base, End, FALSE);

+      break;

+    case EfiAcpiAddressRangeReserved:

+      //

+      // hvmloader marks a range that overlaps with the local APIC memory

+      // mapped region as reserved, but CpuDxe wants it as mapped IO. We

+      // have already added it as mapped IO, so skip it here.

+      //

 

       //

-      // Only care about RAM

+      // add LAPIC predecessor range, if any

       //

-      if (Entry->Type != EfiAcpiAddressRangeMemory) {

-        continue;

+      ReservedBase = Base;

+      ReservedEnd = MIN (End, LapicBase);

+      if (ReservedBase < ReservedEnd) {

+        AddReservedMemoryRangeHob (ReservedBase, ReservedEnd, FALSE);

       }

 

-      AddMemoryBaseSizeHob (Entry->BaseAddr, Entry->Length);

-

-      MtrrSetMemoryAttribute (Entry->BaseAddr, Entry->Length, CacheWriteBack);

+      //

+      // add LAPIC successor range, if any

+      //

+      ReservedBase = MAX (Base, LapicEnd);

+      ReservedEnd = End;

+      if (ReservedBase < ReservedEnd) {

+        AddReservedMemoryRangeHob (ReservedBase, ReservedEnd, FALSE);

+      }

+      break;

+    default:

+      break;

     }

   }

 }

@@ -326,12 +365,6 @@ InitializeXen (
 {

   RETURN_STATUS PcdStatus;

 

-  //

-  // Reserve away HVMLOADER reserved memory [0xFC000000,0xFD000000).

-  // This needs to match HVMLOADER RESERVED_MEMBASE/RESERVED_MEMSIZE.

-  //

-  AddReservedMemoryBaseSizeHob (0xFC000000, 0x1000000, FALSE);

-

   PcdStatus = PcdSetBoolS (PcdPciDisableBusEnumeration, TRUE);

   ASSERT_RETURN_ERROR (PcdStatus);