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>

hw/tpm/Makefile.objs

@@ -1,4 +1,5 @@
 common-obj-y += tpm_util.o
+obj-y += tpm_ppi.o
 common-obj-$(CONFIG_TPM_TIS) += tpm_tis.o
 common-obj-$(CONFIG_TPM_CRB) += tpm_crb.o
 common-obj-$(CONFIG_TPM_PASSTHROUGH) += tpm_passthrough.o

hw/tpm/tpm_crb.c

@@ -29,6 +29,7 @@
 #include "sysemu/reset.h"
 #include "tpm_int.h"
 #include "tpm_util.h"
+#include "tpm_ppi.h"
 #include "trace.h"
 
 typedef struct CRBState {
@@ -43,6 +44,7 @@ typedef struct CRBState {
     size_t be_buffer_size;
 
     bool ppi_enabled;
+    TPMPPI ppi;
 } CRBState;
 
 #define CRB(obj) OBJECT_CHECK(CRBState, (obj), TYPE_TPM_CRB)
@@ -294,6 +296,11 @@ static void tpm_crb_realize(DeviceState *dev, Error **errp)
     memory_region_add_subregion(get_system_memory(),
         TPM_CRB_ADDR_BASE + sizeof(s->regs), &s->cmdmem);
 
+    if (s->ppi_enabled) {
+        tpm_ppi_init(&s->ppi, get_system_memory(),
+                     TPM_PPI_ADDR_BASE, OBJECT(s));
+    }
+
     qemu_register_reset(tpm_crb_reset, dev);
 }
 

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);
+}

hw/tpm/tpm_ppi.h

@@ -0,0 +1,36 @@
+/*
+ * 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.
+ */
+#ifndef TPM_TPM_PPI_H
+#define TPM_TPM_PPI_H
+
+#include "hw/acpi/tpm.h"
+#include "exec/address-spaces.h"
+
+typedef struct TPMPPI {
+    MemoryRegion ram;
+    uint8_t *buf;
+} TPMPPI;
+
+/**
+ * tpm_ppi_init:
+ * @tpmppi: a TPMPPI
+ * @m: the address-space / MemoryRegion to use
+ * @addr: the address of the PPI region
+ * @obj: the owner object
+ *
+ * Register the TPM PPI memory region at @addr on the given address
+ * space for the object @obj.
+ **/
+void tpm_ppi_init(TPMPPI *tpmppi, struct MemoryRegion *m,
+                  hwaddr addr, Object *obj);
+
+#endif /* TPM_TPM_PPI_H */

hw/tpm/tpm_tis.c

@@ -31,6 +31,7 @@
 #include "sysemu/tpm_backend.h"
 #include "tpm_int.h"
 #include "tpm_util.h"
+#include "tpm_ppi.h"
 #include "trace.h"
 
 #define TPM_TIS_NUM_LOCALITIES      5     /* per spec */
@@ -83,6 +84,7 @@ typedef struct TPMState {
     size_t be_buffer_size;
 
     bool ppi_enabled;
+    TPMPPI ppi;
 } TPMState;
 
 #define TPM(obj) OBJECT_CHECK(TPMState, (obj), TYPE_TPM_TIS)
@@ -983,6 +985,11 @@ static void tpm_tis_realizefn(DeviceState *dev, Error **errp)
 
     memory_region_add_subregion(isa_address_space(ISA_DEVICE(dev)),
                                 TPM_TIS_ADDR_BASE, &s->mmio);
+
+    if (s->ppi_enabled) {
+        tpm_ppi_init(&s->ppi, isa_address_space(ISA_DEVICE(dev)),
+                     TPM_PPI_ADDR_BASE, OBJECT(s));
+    }
 }
 
 static void tpm_tis_initfn(Object *obj)

include/hw/acpi/tpm.h

@@ -188,4 +188,10 @@ REG32(CRB_DATA_BUFFER, 0x80)
 #define TPM2_START_METHOD_MMIO      6
 #define TPM2_START_METHOD_CRB       7
 
+/*
+ * Physical Presence Interface
+ */
+#define TPM_PPI_ADDR_SIZE           0x400
+#define TPM_PPI_ADDR_BASE           0xFED45000
+
 #endif /* HW_ACPI_TPM_H */