[RFC PATCH 3/5] OvmfPkg/CpuHotplugSmm: add CpuStatus helper function

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

Add QemuCpuhpWriteCpuStatus() which writes to the QEMU CPU status register.
On error, it hangs in similar fashion to the other helper functions.

Signed-off-by: Ankur Arora <ankur.a.arora@oracle.com>
---
 OvmfPkg/CpuHotplugSmm/QemuCpuhp.c | 23 +++++++++++++++++++++++
 OvmfPkg/CpuHotplugSmm/QemuCpuhp.h |  6 ++++++
 2 files changed, 29 insertions(+)

diff --git a/OvmfPkg/CpuHotplugSmm/QemuCpuhp.c b/OvmfPkg/CpuHotplugSmm/QemuCpuhp.c
index 2dd783ebf42e..14145696aa50 100644
--- a/OvmfPkg/CpuHotplugSmm/QemuCpuhp.c
+++ b/OvmfPkg/CpuHotplugSmm/QemuCpuhp.c
@@ -67,6 +67,29 @@ QemuCpuhpReadCpuStatus (
   return CpuStatus;
 }
 
+UINT8
+QemuCpuhpWriteCpuStatus (
+  IN CONST EFI_MM_CPU_IO_PROTOCOL *MmCpuIo,
+  IN UINT8                        CpuStatus
+  )
+{
+  EFI_STATUS Status;
+
+  Status = MmCpuIo->Io.Write(
+                         MmCpuIo,
+                         MM_IO_UINT8,
+                         ICH9_CPU_HOTPLUG_BASE + QEMU_CPUHP_R_CPU_STAT,
+                         1,
+                         &CpuStatus
+                         );
+  if (EFI_ERROR (Status)) {
+    DEBUG ((DEBUG_ERROR, "%a: %r\n", __FUNCTION__, Status));
+    ASSERT (FALSE);
+    CpuDeadLoop ();
+  }
+  return Status;
+}
+
 UINT32
 QemuCpuhpReadCommandData (
   IN CONST EFI_MM_CPU_IO_PROTOCOL *MmCpuIo
diff --git a/OvmfPkg/CpuHotplugSmm/QemuCpuhp.h b/OvmfPkg/CpuHotplugSmm/QemuCpuhp.h
index 8adaa0ad91f0..9f084d199fd4 100644
--- a/OvmfPkg/CpuHotplugSmm/QemuCpuhp.h
+++ b/OvmfPkg/CpuHotplugSmm/QemuCpuhp.h
@@ -30,6 +30,12 @@ QemuCpuhpReadCpuStatus (
   IN CONST EFI_MM_CPU_IO_PROTOCOL *MmCpuIo
   );
 
+UINT8
+QemuCpuhpWriteCpuStatus (
+  IN CONST EFI_MM_CPU_IO_PROTOCOL *MmCpuIo,
+  IN UINT8                        CpuStatus
+  );
+
 UINT32
 QemuCpuhpReadCommandData (
   IN CONST EFI_MM_CPU_IO_PROTOCOL *MmCpuIo
-- 
2.25.4