OvmfPkg/CpuHotplugSmm: add hotplug register block helper functions

Add a handful of simple functions for accessing QEMU's hotplug registers
more conveniently. These functions thinly wrap some of the registers
described in "docs/specs/acpi_cpu_hotplug.txt" in the QEMU tree. The
functions hang (by design) if they encounter an internal failure.

Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Michael Kinney <michael.d.kinney@intel.com>
Cc: Philippe Mathieu-Daudé <philmd@redhat.com>
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=1512
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20200226221156.29589-8-lersek@redhat.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Philippe Mathieu-Daude <philmd@redhat.com>
Tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>

3 files changed, 185 insertions, 0 deletions

diff --git a/OvmfPkg/CpuHotplugSmm/CpuHotplugSmm.inf b/OvmfPkg/CpuHotplugSmm/CpuHotplugSmm.inf
index fa70858a8d..ac4ca4c1f4 100644
--- a/OvmfPkg/CpuHotplugSmm/CpuHotplugSmm.inf
+++ b/OvmfPkg/CpuHotplugSmm/CpuHotplugSmm.inf
@@ -23,6 +23,8 @@
 

 [Sources]

   CpuHotplug.c

+  QemuCpuhp.c

+  QemuCpuhp.h

 

 [Packages]

   MdePkg/MdePkg.dec

diff --git a/OvmfPkg/CpuHotplugSmm/QemuCpuhp.c b/OvmfPkg/CpuHotplugSmm/QemuCpuhp.c
new file mode 100644
index 0000000000..31e46f5193
--- /dev/null
+++ b/OvmfPkg/CpuHotplugSmm/QemuCpuhp.c
@@ -0,0 +1,136 @@
+/** @file

+  Simple wrapper functions that access QEMU's modern CPU hotplug register

+  block.

+

+  These functions thinly wrap some of the registers described in

+  "docs/specs/acpi_cpu_hotplug.txt" in the QEMU source. IO Ports are accessed

+  via EFI_MM_CPU_IO_PROTOCOL. If a protocol call fails, these functions don't

+  return.

+

+  Copyright (c) 2020, Red Hat, Inc.

+

+  SPDX-License-Identifier: BSD-2-Clause-Patent

+**/

+

+#include <IndustryStandard/Q35MchIch9.h>     // ICH9_CPU_HOTPLUG_BASE

+#include <IndustryStandard/QemuCpuHotplug.h> // QEMU_CPUHP_R_CMD_DATA2

+#include <Library/BaseLib.h>                 // CpuDeadLoop()

+#include <Library/DebugLib.h>                // DEBUG()

+

+#include "QemuCpuhp.h"

+

+UINT32

+QemuCpuhpReadCommandData2 (

+  IN CONST EFI_MM_CPU_IO_PROTOCOL *MmCpuIo

+  )

+{

+  UINT32     CommandData2;

+  EFI_STATUS Status;

+

+  CommandData2 = 0;

+  Status = MmCpuIo->Io.Read (

+                         MmCpuIo,

+                         MM_IO_UINT32,

+                         ICH9_CPU_HOTPLUG_BASE + QEMU_CPUHP_R_CMD_DATA2,

+                         1,

+                         &CommandData2

+                         );

+  if (EFI_ERROR (Status)) {

+    DEBUG ((DEBUG_ERROR, "%a: %r\n", __FUNCTION__, Status));

+    ASSERT (FALSE);

+    CpuDeadLoop ();

+  }

+  return CommandData2;

+}

+

+UINT8

+QemuCpuhpReadCpuStatus (

+  IN CONST EFI_MM_CPU_IO_PROTOCOL *MmCpuIo

+  )

+{

+  UINT8      CpuStatus;

+  EFI_STATUS Status;

+

+  CpuStatus = 0;

+  Status = MmCpuIo->Io.Read (

+                         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 CpuStatus;

+}

+

+UINT32

+QemuCpuhpReadCommandData (

+  IN CONST EFI_MM_CPU_IO_PROTOCOL *MmCpuIo

+  )

+{

+  UINT32     CommandData;

+  EFI_STATUS Status;

+

+  CommandData = 0;

+  Status = MmCpuIo->Io.Read (

+                         MmCpuIo,

+                         MM_IO_UINT32,

+                         ICH9_CPU_HOTPLUG_BASE + QEMU_CPUHP_RW_CMD_DATA,

+                         1,

+                         &CommandData

+                         );

+  if (EFI_ERROR (Status)) {

+    DEBUG ((DEBUG_ERROR, "%a: %r\n", __FUNCTION__, Status));

+    ASSERT (FALSE);

+    CpuDeadLoop ();

+  }

+  return CommandData;

+}

+

+VOID

+QemuCpuhpWriteCpuSelector (

+  IN CONST EFI_MM_CPU_IO_PROTOCOL *MmCpuIo,

+  IN UINT32                       Selector

+  )

+{

+  EFI_STATUS Status;

+

+  Status = MmCpuIo->Io.Write (

+                         MmCpuIo,

+                         MM_IO_UINT32,

+                         ICH9_CPU_HOTPLUG_BASE + QEMU_CPUHP_W_CPU_SEL,

+                         1,

+                         &Selector

+                         );

+  if (EFI_ERROR (Status)) {

+    DEBUG ((DEBUG_ERROR, "%a: %r\n", __FUNCTION__, Status));

+    ASSERT (FALSE);

+    CpuDeadLoop ();

+  }

+}

+

+VOID

+QemuCpuhpWriteCommand (

+  IN CONST EFI_MM_CPU_IO_PROTOCOL *MmCpuIo,

+  IN UINT8                        Command

+  )

+{

+  EFI_STATUS Status;

+

+  Status = MmCpuIo->Io.Write (

+                         MmCpuIo,

+                         MM_IO_UINT8,

+                         ICH9_CPU_HOTPLUG_BASE + QEMU_CPUHP_W_CMD,

+                         1,

+                         &Command

+                         );

+  if (EFI_ERROR (Status)) {

+    DEBUG ((DEBUG_ERROR, "%a: %r\n", __FUNCTION__, Status));

+    ASSERT (FALSE);

+    CpuDeadLoop ();

+  }

+}

diff --git a/OvmfPkg/CpuHotplugSmm/QemuCpuhp.h b/OvmfPkg/CpuHotplugSmm/QemuCpuhp.h
new file mode 100644
index 0000000000..82f88f0b73
--- /dev/null
+++ b/OvmfPkg/CpuHotplugSmm/QemuCpuhp.h
@@ -0,0 +1,47 @@
+/** @file

+  Simple wrapper functions that access QEMU's modern CPU hotplug register

+  block.

+

+  These functions thinly wrap some of the registers described in

+  "docs/specs/acpi_cpu_hotplug.txt" in the QEMU source. IO Ports are accessed

+  via EFI_MM_CPU_IO_PROTOCOL. If a protocol call fails, these functions don't

+  return.

+

+  Copyright (c) 2020, Red Hat, Inc.

+

+  SPDX-License-Identifier: BSD-2-Clause-Patent

+**/

+

+#ifndef QEMU_CPUHP_H_

+#define QEMU_CPUHP_H_

+

+#include <Protocol/MmCpuIo.h>  // EFI_MM_CPU_IO_PROTOCOL

+

+UINT32

+QemuCpuhpReadCommandData2 (

+  IN CONST EFI_MM_CPU_IO_PROTOCOL *MmCpuIo

+  );

+

+UINT8

+QemuCpuhpReadCpuStatus (

+  IN CONST EFI_MM_CPU_IO_PROTOCOL *MmCpuIo

+  );

+

+UINT32

+QemuCpuhpReadCommandData (

+  IN CONST EFI_MM_CPU_IO_PROTOCOL *MmCpuIo

+  );

+

+VOID

+QemuCpuhpWriteCpuSelector (

+  IN CONST EFI_MM_CPU_IO_PROTOCOL *MmCpuIo,

+  IN UINT32                       Selector

+  );

+

+VOID

+QemuCpuhpWriteCommand (

+  IN CONST EFI_MM_CPU_IO_PROTOCOL *MmCpuIo,

+  IN UINT8                        Command

+  );

+

+#endif // QEMU_CPUHP_H_