tpm: allocate/map buffer for TPM Physical Presence interface

Implement a virtual memory device for the TPM Physical Presence interface.
The memory is located at 0xFED45000 and used by ACPI to send messages to the
firmware (BIOS) and by the firmware to provide parameters for each one of
the supported codes.

This interface should be used by all TPM devices on x86 and can be
added by calling tpm_ppi_init_io().

Note: bios_linker cannot be used to allocate the PPI memory region,
since the reserved memory should stay stable across reboots, and might
be needed before the ACPI tables are installed.

Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Tested-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 31 insertions, 0 deletions

diff --git a/hw/tpm/tpm_ppi.c b/hw/tpm/tpm_ppi.c
new file mode 100644
index 0000000000..cf17779c20
--- /dev/null
+++ b/hw/tpm/tpm_ppi.c
@@ -0,0 +1,31 @@
+/*
+ * tpm_ppi.c - TPM Physical Presence Interface
+ *
+ * Copyright (C) 2018 IBM Corporation
+ *
+ * Authors:
+ *  Stefan Berger <stefanb@us.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#include "qemu/osdep.h"
+
+#include "qapi/error.h"
+#include "cpu.h"
+#include "sysemu/memory_mapping.h"
+#include "migration/vmstate.h"
+#include "tpm_ppi.h"
+
+void tpm_ppi_init(TPMPPI *tpmppi, struct MemoryRegion *m,
+                  hwaddr addr, Object *obj)
+{
+    tpmppi->buf = g_malloc0(HOST_PAGE_ALIGN(TPM_PPI_ADDR_SIZE));
+    memory_region_init_ram_device_ptr(&tpmppi->ram, obj, "tpm-ppi",
+                                      TPM_PPI_ADDR_SIZE, tpmppi->buf);
+    vmstate_register_ram(&tpmppi->ram, DEVICE(obj));
+
+    memory_region_add_subregion(m, addr, &tpmppi->ram);
+}