[PATCH v8 06/10] OvmfPkg/SmmCpuFeaturesLib: init CPU ejection state

["Ankur Arora" <ankur.a.arora@oracle.com>]

Init CPU_HOT_EJECT_DATA, which will be used to share CPU ejection
state between SmmCpuFeaturesLib (via PiSmmCpuDxeSmm) and CpuHotPlugSmm.

The init happens via SmmCpuFeaturesSmmRelocationComplete(), and so it
will run as part of the PiSmmCpuDxeSmm entry point function,
PiCpuSmmEntry(). Once inited, CPU_HOT_EJECT_DATA is exposed via
PcdCpuHotEjectDataAddress.

The CPU hot-eject handler (CPU_HOT_EJECT_DATA->Handler) is setup when
there is an ejection request via CpuHotplugSmm.

Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Aaron Young <aaron.young@oracle.com>
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=3132
Signed-off-by: Ankur Arora <ankur.a.arora@oracle.com>
---

Notes:
    Addresses the following review comments:
     (1) Detail in commit message about context in which CPU_HOT_EJECT_DATA
      is inited.
     (2) Add in sorted order MemoryAllocationLib in LibraryClasses
     (3) Sort added includes in SmmCpuFeaturesLib.c
     (4a-4b) Fixup linkage directives for mCpuHotEjectData.
     (5) s/CpuHotEjectData/mCpuHotEjectData/
     (6,10a,10b) Remove dependence on PcdCpuHotPlugSupport
     (7) Make the tense structure consistent in block comment for
      InitCpuHotEject().
     (8) s/SmmCpuFeaturesSmmInitHotEject/InitCpuHotEject/
     (9) s/mMaxNumberOfCpus/MaxNumberOfCpus/
     (11) Remove a bunch of obvious comments.
     (14a,14b,14c) Use SafeUint functions and rework the allocation logic
      so we can just use a single allocation.
     (12) Remove the AllocatePool() cast.
     (13) Use a CpuDeadLoop() in case of failure; albeit via a goto, not
      inline.
     (15) Initialize the mCpuHotEjectData->QemuSelectorMap locally.
     (16) Fix indentation in PcdSet64S.
     (17) Change the cast in PcdSet64S() to UINTN.
     (18) Use RETURN_STATUS instead of EFI_STATUS.
     (19,20) Move the Handler logic in SmmCpuFeaturesRendezvousExit() into
      into a separate patch.

 .../SmmCpuFeaturesLib/SmmCpuFeaturesLib.inf        |  4 +
 .../Library/SmmCpuFeaturesLib/SmmCpuFeaturesLib.c  | 92 ++++++++++++++++++++++
 2 files changed, 96 insertions(+)

diff --git a/OvmfPkg/Library/SmmCpuFeaturesLib/SmmCpuFeaturesLib.inf b/OvmfPkg/Library/SmmCpuFeaturesLib/SmmCpuFeaturesLib.inf
index 97a10afb6e27..8a426a4c10fb 100644
--- a/OvmfPkg/Library/SmmCpuFeaturesLib/SmmCpuFeaturesLib.inf
+++ b/OvmfPkg/Library/SmmCpuFeaturesLib/SmmCpuFeaturesLib.inf
@@ -30,9 +30,13 @@ [LibraryClasses]
   BaseMemoryLib
   DebugLib
   MemEncryptSevLib
+  MemoryAllocationLib
   PcdLib
+  SafeIntLib
   SmmServicesTableLib
   UefiBootServicesTableLib
 
 [Pcd]
+  gUefiCpuPkgTokenSpaceGuid.PcdCpuMaxLogicalProcessorNumber
+  gUefiOvmfPkgTokenSpaceGuid.PcdCpuHotEjectDataAddress
   gUefiOvmfPkgTokenSpaceGuid.PcdQ35SmramAtDefaultSmbase
diff --git a/OvmfPkg/Library/SmmCpuFeaturesLib/SmmCpuFeaturesLib.c b/OvmfPkg/Library/SmmCpuFeaturesLib/SmmCpuFeaturesLib.c
index 7ef7ed98342e..adbfc90ad46e 100644
--- a/OvmfPkg/Library/SmmCpuFeaturesLib/SmmCpuFeaturesLib.c
+++ b/OvmfPkg/Library/SmmCpuFeaturesLib/SmmCpuFeaturesLib.c
@@ -11,10 +11,13 @@
 #include <Library/BaseMemoryLib.h>
 #include <Library/DebugLib.h>
 #include <Library/MemEncryptSevLib.h>
+#include <Library/MemoryAllocationLib.h>
 #include <Library/PcdLib.h>
+#include <Library/SafeIntLib.h>
 #include <Library/SmmCpuFeaturesLib.h>
 #include <Library/SmmServicesTableLib.h>
 #include <Library/UefiBootServicesTableLib.h>
+#include <Pcd/CpuHotEjectData.h>
 #include <PiSmm.h>
 #include <Register/Intel/SmramSaveStateMap.h>
 #include <Register/QemuSmramSaveStateMap.h>
@@ -171,6 +174,92 @@ SmmCpuFeaturesHookReturnFromSmm (
   return OriginalInstructionPointer;
 }
 
+STATIC CPU_HOT_EJECT_DATA *mCpuHotEjectData = NULL;
+
+/**
+  Initialize mCpuHotEjectData if PcdCpuMaxLogicalProcessorNumber > 1.
+
+  Also setup the corresponding PcdCpuHotEjectDataAddress.
+**/
+STATIC
+VOID
+InitCpuHotEjectData (
+  VOID
+  )
+{
+  UINTN          ArrayLen;
+  UINTN          BaseLen;
+  UINTN          TotalLen;
+  UINT32         Idx;
+  UINT32         MaxNumberOfCpus;
+  RETURN_STATUS  PcdStatus;
+
+  MaxNumberOfCpus = PcdGet32 (PcdCpuMaxLogicalProcessorNumber);
+
+  if (MaxNumberOfCpus == 1) {
+    return;
+  }
+
+  //
+  // We want the following lay out for CPU_HOT_EJECT_DATA:
+  //  UINTN alignment:  CPU_HOT_EJECT_DATA
+  //                  --- padding if needed ---
+  //  UINT64 alignment:  CPU_HOT_EJECT_DATA->QemuSelectorMap[]
+  //
+  // Accordingly, we allocate:
+  //   sizeof(*mCpuHotEjectData) + (MaxNumberOfCpus *
+  //     sizeof(mCpuHotEjectData->QemuSelectorMap[0])).
+  // Add sizeof(UINT64) to use as padding if needed.
+  //
+
+  if (RETURN_ERROR (SafeUintnMult (sizeof (*mCpuHotEjectData), 1, &BaseLen)) ||
+      RETURN_ERROR (SafeUintnMult (
+                      sizeof (mCpuHotEjectData->QemuSelectorMap[0]),
+                      MaxNumberOfCpus, &ArrayLen)) ||
+      RETURN_ERROR (SafeUintnAdd (BaseLen, ArrayLen, &TotalLen))||
+      RETURN_ERROR (SafeUintnAdd (TotalLen, sizeof (UINT64), &TotalLen))) {
+    DEBUG ((DEBUG_ERROR, "%a: invalid CPU_HOT_EJECT_DATA\n", __FUNCTION__));
+    goto Fatal;
+  }
+
+  mCpuHotEjectData = AllocatePool (TotalLen);
+  if (mCpuHotEjectData == NULL) {
+    ASSERT (mCpuHotEjectData != NULL);
+    goto Fatal;
+  }
+
+  mCpuHotEjectData->Handler = NULL;
+  mCpuHotEjectData->ArrayLength = MaxNumberOfCpus;
+
+  mCpuHotEjectData->QemuSelectorMap = (void *)mCpuHotEjectData +
+                                        sizeof (*mCpuHotEjectData);
+  mCpuHotEjectData->QemuSelectorMap =
+    (void *)ALIGN_VALUE ((UINTN)mCpuHotEjectData->QemuSelectorMap,
+                           sizeof (UINT64));
+  //
+  // We use mCpuHotEjectData->QemuSelectorMap to map
+  // ProcessorNum -> QemuSelector. Initialize to invalid values.
+  //
+  for (Idx = 0; Idx < mCpuHotEjectData->ArrayLength; Idx++) {
+    mCpuHotEjectData->QemuSelectorMap[Idx] = CPU_EJECT_QEMU_SELECTOR_INVALID;
+  }
+
+  //
+  // Expose address of CPU Hot eject Data structure
+  //
+  PcdStatus = PcdSet64S (PcdCpuHotEjectDataAddress,
+                (UINTN)(VOID *)mCpuHotEjectData);
+  if (RETURN_ERROR (PcdStatus)) {
+    ASSERT_EFI_ERROR (PcdStatus);
+    goto Fatal;
+  }
+
+  return;
+
+Fatal:
+  CpuDeadLoop ();
+}
+
 /**
   Hook point in normal execution mode that allows the one CPU that was elected
   as monarch during System Management Mode initialization to perform additional
@@ -188,6 +277,9 @@ SmmCpuFeaturesSmmRelocationComplete (
   UINTN      MapPagesBase;
   UINTN      MapPagesCount;
 
+
+  InitCpuHotEjectData ();
+
   if (!MemEncryptSevIsEnabled ()) {
     return;
   }
-- 
2.9.3