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[PATCH v4 1/3] tpm/tpm_tis_spi: Support TPM for SPI (Serial Peripheral I
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From: |
dan tan |
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Subject: |
[PATCH v4 1/3] tpm/tpm_tis_spi: Support TPM for SPI (Serial Peripheral Interface) |
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Date: |
Fri, 1 Nov 2024 15:27:25 -0500 |
Implement support for TPM via SPI interface. The SPI bus master
is provided by PowerNV SPI device which is an SSI peripheral.
It can uses the tpm_emulator driver backend with the external
swtpm.
Although the implementation is endian neutral, the SPI
bus master provider, pnv_spi.c is only supported on the
PowerNV platform, thus, is big endian specific.
tpm/tpm_tis_spi: Support TPM for SPI (rev 4)
- moved variable tis_addr from TPMStateSPI struct to local
- added the VM suspend/resume support:
- added vmstate_tpm_tis_spi declaration
- added tpm_tis_spi_pre_save() function
- fixed trace formatting string
Signed-off-by: dan tan <dantan@linux.vnet.ibm.com>
---
docs/specs/tpm.rst | 15 ++
include/sysemu/tpm.h | 3 +
hw/tpm/tpm_tis_spi.c | 360 +++++++++++++++++++++++++++++++++++++++++++
hw/tpm/Kconfig | 6 +
hw/tpm/meson.build | 1 +
hw/tpm/trace-events | 7 +
6 files changed, 392 insertions(+)
create mode 100644 hw/tpm/tpm_tis_spi.c
diff --git a/docs/specs/tpm.rst b/docs/specs/tpm.rst
index 1ad36ad709..63c3a43c7d 100644
--- a/docs/specs/tpm.rst
+++ b/docs/specs/tpm.rst
@@ -24,6 +24,7 @@ QEMU files related to TPM TIS interface:
- ``hw/tpm/tpm_tis_isa.c``
- ``hw/tpm/tpm_tis_sysbus.c``
- ``hw/tpm/tpm_tis_i2c.c``
+ - ``hw/tpm/tpm_tis_spi.c``
- ``hw/tpm/tpm_tis.h``
Both an ISA device and a sysbus device are available. The former is
@@ -33,6 +34,9 @@ Arm virt machine.
An I2C device support is also provided which can be instantiated in the Arm
based emulation machines. This device only supports the TPM 2 protocol.
+A Serial Peripheral Interface (SPI) device support has been added to the
+PowerNV emulation machines. This device only supports the TPM 2 protocol.
+
CRB interface
-------------
@@ -371,6 +375,17 @@ attached to I2C bus, use the following command line:
echo tpm_tis_i2c 0x2e > /sys/bus/i2c/devices/i2c-12/new_device
+In case a PowerNV machine is emulated and you want to use a TPM device
+attached to SPI bus, use the following command line (SPI bus master is
+provided by PowerNV SPI device):
+
+.. code-block:: console
+
+ qemu-system-ppc64 -m 2G -machine powernv10 -nographic \
+ -chardev socket,id=chrtpm,path=/tmp/mytpm1/swtpm-sock \
+ -tpmdev emulator,id=tpm0,chardev=chrtpm \
+ -device tpm-tis-spi,tpmdev=tpm0,bus=pnv-spi-bus.4
+
In case SeaBIOS is used as firmware, it should show the TPM menu item
after entering the menu with 'ESC'.
diff --git a/include/sysemu/tpm.h b/include/sysemu/tpm.h
index 1ee568b3b6..22b05110e2 100644
--- a/include/sysemu/tpm.h
+++ b/include/sysemu/tpm.h
@@ -49,6 +49,7 @@ struct TPMIfClass {
#define TYPE_TPM_CRB "tpm-crb"
#define TYPE_TPM_SPAPR "tpm-spapr"
#define TYPE_TPM_TIS_I2C "tpm-tis-i2c"
+#define TYPE_TPM_TIS_SPI "tpm-tis-spi"
#define TPM_IS_TIS_ISA(chr) \
object_dynamic_cast(OBJECT(chr), TYPE_TPM_TIS_ISA)
@@ -60,6 +61,8 @@ struct TPMIfClass {
object_dynamic_cast(OBJECT(chr), TYPE_TPM_SPAPR)
#define TPM_IS_TIS_I2C(chr) \
object_dynamic_cast(OBJECT(chr), TYPE_TPM_TIS_I2C)
+#define TPM_IS_TIS_SPI(chr) \
+ object_dynamic_cast(OBJECT(chr), TYPE_TPM_TIS_SPI)
/* returns NULL unless there is exactly one TPM device */
static inline TPMIf *tpm_find(void)
diff --git a/hw/tpm/tpm_tis_spi.c b/hw/tpm/tpm_tis_spi.c
new file mode 100644
index 0000000000..4aee1c6d6c
--- /dev/null
+++ b/hw/tpm/tpm_tis_spi.c
@@ -0,0 +1,360 @@
+/*
+ * QEMU PowerPC SPI TPM 2.0 model
+ *
+ * Copyright (c) 2024, IBM Corporation.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#define IBM_PONQ
+
+#include "qemu/osdep.h"
+#include "qemu/log.h"
+#include "hw/sysbus.h"
+#include "hw/acpi/tpm.h"
+#include "tpm_prop.h"
+#include "qemu/log.h"
+#include "trace.h"
+#include "tpm_tis.h"
+#include "hw/ssi/ssi.h"
+#include "migration/vmstate.h"
+
+typedef struct TPMStateSPI {
+ /*< private >*/
+ SSIPeripheral parent_object;
+
+ uint8_t byte_offset; /* byte offset in transfer */
+ uint8_t wait_state_cnt; /* wait state counter */
+ uint8_t xfer_size; /* data size of transfer */
+ uint32_t reg_addr; /* register address of transfer */
+
+ uint8_t spi_state; /* READ / WRITE / IDLE */
+#define SPI_STATE_IDLE 0
+#define SPI_STATE_WRITE 1
+#define SPI_STATE_READ 2
+
+ bool command;
+
+ /*< public >*/
+ TPMState tpm_state; /* not a QOM object */
+
+} TPMStateSPI;
+
+#define CMD_BYTE_WRITE (1 << 7)
+#define CMD_BYTE_XFER_SZ_MASK 0x1f
+#define TIS_SPI_HIGH_ADDR_BYTE 0xd4
+
+DECLARE_INSTANCE_CHECKER(TPMStateSPI, TPM_TIS_SPI, TYPE_TPM_TIS_SPI)
+
+static int tpm_tis_spi_pre_save(void *opaque)
+{
+ TPMStateSPI *spist = opaque;
+
+ return tpm_tis_pre_save(&spist->tpm_state);
+}
+
+static const VMStateDescription vmstate_tpm_tis_spi = {
+ .name = "tpm-tis-spi",
+ .version_id = 0,
+ .pre_save = tpm_tis_spi_pre_save,
+ .fields = (const VMStateField[]) {
+ VMSTATE_BUFFER(tpm_state.buffer, TPMStateSPI),
+ VMSTATE_UINT16(tpm_state.rw_offset, TPMStateSPI),
+ VMSTATE_UINT8(tpm_state.active_locty, TPMStateSPI),
+ VMSTATE_UINT8(tpm_state.aborting_locty, TPMStateSPI),
+ VMSTATE_UINT8(tpm_state.next_locty, TPMStateSPI),
+
+ VMSTATE_STRUCT_ARRAY(tpm_state.loc, TPMStateSPI,
+ TPM_TIS_NUM_LOCALITIES, 0,
+ vmstate_locty, TPMLocality),
+
+ /* spi specifics */
+ VMSTATE_UINT8(byte_offset, TPMStateSPI),
+ VMSTATE_UINT8(wait_state_cnt, TPMStateSPI),
+ VMSTATE_UINT8(xfer_size, TPMStateSPI),
+ VMSTATE_UINT32(reg_addr, TPMStateSPI),
+ VMSTATE_UINT8(spi_state, TPMStateSPI),
+ VMSTATE_BOOL(command, TPMStateSPI),
+
+ VMSTATE_END_OF_LIST()
+ }
+};
+
+static inline void tpm_tis_spi_clear_data(TPMStateSPI *spist)
+{
+ spist->spi_state = SPI_STATE_IDLE;
+ spist->byte_offset = 0;
+ spist->wait_state_cnt = 0;
+ spist->xfer_size = 0;
+ spist->reg_addr = 0;
+
+ return;
+}
+
+/* Callback from TPM to indicate that response is copied */
+static void tpm_tis_spi_request_completed(TPMIf *ti, int ret)
+{
+ TPMStateSPI *spist = TPM_TIS_SPI(ti);
+ TPMState *s = &spist->tpm_state;
+
+ /* Inform the common code. */
+ tpm_tis_request_completed(s, ret);
+}
+
+static enum TPMVersion tpm_tis_spi_get_tpm_version(TPMIf *ti)
+{
+ TPMStateSPI *spist = TPM_TIS_SPI(ti);
+ TPMState *s = &spist->tpm_state;
+
+ return tpm_tis_get_tpm_version(s);
+}
+
+/*
+ * TCG PC Client Platform TPM Profile Specification for TPM 2.0 ver 1.05 rev 14
+ *
+ * For system Software, the TPM has a 64-bit address of 0x0000_0000_FED4_xxxx.
+ * On SPI, the chipset passes the least significant 24 bits to the TPM.
+ * The upper bytes will be used by the chipset to select the TPM’s SPI CS#
+ * signal. Table 9 shows the locality based on the 16 least significant address
+ * bits and assume that either the LPC TPM sync or SPI TPM CS# is used.
+ *
+ */
+static void tpm_tis_spi_write(TPMStateSPI *spist, uint32_t addr, uint8_t val)
+{
+ TPMState *tpm_st = &spist->tpm_state;
+
+ trace_tpm_tis_spi_write(addr, val);
+ tpm_tis_write_data(tpm_st, addr, val, 1);
+}
+
+static uint8_t tpm_tis_spi_read(TPMStateSPI *spist, uint32_t addr)
+{
+ TPMState *tpm_st = &spist->tpm_state;
+ uint8_t data;
+
+ data = tpm_tis_read_data(tpm_st, addr, 1);
+ trace_tpm_tis_spi_read(addr, data);
+ return data;
+}
+
+static Property tpm_tis_spi_properties[] = {
+ DEFINE_PROP_TPMBE("tpmdev", TPMStateSPI, tpm_state.be_driver),
+ DEFINE_PROP_UINT32("irq", TPMStateSPI, tpm_state.irq_num, 0),
+ DEFINE_PROP_END_OF_LIST(),
+};
+
+static void tpm_tis_spi_reset(DeviceState *dev)
+{
+ TPMStateSPI *spist = TPM_TIS_SPI(dev);
+ TPMState *s = &spist->tpm_state;
+
+ tpm_tis_spi_clear_data(spist);
+ return tpm_tis_reset(s);
+}
+
+static uint32_t tpm_transfer(SSIPeripheral *ss, uint32_t tx)
+{
+ TPMStateSPI *spist = TPM_TIS_SPI(ss);
+ uint32_t rx = 0;
+ uint8_t byte; /* reversed byte value */
+ uint8_t offset = 0; /* offset of byte in payload */
+ uint8_t index; /* index of data byte in transfer */
+ uint32_t tis_addr; /* tis address including locty */
+
+ /* new transfer or not */
+ if (spist->command) { /* new transfer start */
+ if (spist->spi_state != SPI_STATE_IDLE) {
+ qemu_log_mask(LOG_GUEST_ERROR, "unexpected new transfer\n");
+ }
+ spist->byte_offset = 0;
+ spist->wait_state_cnt = 0;
+ }
+ /*
+ * Explanation of wait_state:
+ * The original TPM model did not have wait state or "flow control" support
+ * built in. If you wanted to read a TPM register through SPI you sent
+ * the first byte with the read/write bit and size, then three address
bytes
+ * and any additional bytes after that were don't care bytes for reads and
+ * the model would begin returning byte data to the SPI reader from the
+ * register address provided. In the real world this would mean that a
+ * TPM device had only the time between the 31st clock and the 32nd clock
+ * to fetch the register data that it had to provide to SPI MISO starting
+ * with the 32nd clock.
+ *
+ * In reality the TPM begins introducing a wait state at the 31st clock
+ * by holding MISO low. This is how it controls the "flow" of the
+ * operation. Once the data the TPM needs to return is ready it will
+ * select bit 31 + (8*N) to send back a 1 which indicates that it will
+ * now start returning data on MISO.
+ *
+ * The same wait states are applied to writes. In either the read or write
+ * case the wait state occurs between the command+address (4 bytes) and the
+ * data (1-n bytes) sections of the SPI frame. The code below introduces
+ * the support for a 32 bit wait state for P10. All reads and writes
+ * through the SPI interface MUST now be aware of the need to do flow
+ * control in order to use the TPM via SPI.
+ *
+ * In conjunction with these changes there were changes made to the SPIM
+ * engine that was introduced in P10 to support the 6x op code which is
+ * used to receive wait state 0s on the MISO line until it sees the b'1'
+ * come back before continuing to read real data from the SPI device(TPM).
+ */
+
+ trace_tpm_tis_spi_transfer_data("Payload byte_offset", spist->byte_offset);
+ /* process payload data */
+ while (offset < 4) {
+ spist->command = false;
+ byte = (tx >> (24 - 8 * offset)) & 0xFF;
+ trace_tpm_tis_spi_transfer_data("Extracted byte", byte);
+ trace_tpm_tis_spi_transfer_data("Payload offset", offset);
+ switch (spist->byte_offset) {
+ case 0: /* command byte */
+ if ((byte & CMD_BYTE_WRITE) == 0) { /* bit-7 */
+ spist->spi_state = SPI_STATE_WRITE;
+ trace_tpm_tis_spi_transfer_event("spi write");
+ } else {
+ spist->spi_state = SPI_STATE_READ;
+ trace_tpm_tis_spi_transfer_event("spi read");
+ }
+ spist->xfer_size = (byte & CMD_BYTE_XFER_SZ_MASK) + 1;
+ trace_tpm_tis_spi_transfer_data("xfer_size", spist->xfer_size);
+ break;
+ case 1: /* 1st address byte */
+ if (byte != TIS_SPI_HIGH_ADDR_BYTE) {
+ qemu_log_mask(LOG_GUEST_ERROR, "incorrect high address 0x%x\n",
+ byte);
+ }
+ spist->reg_addr = byte << 16;
+ trace_tpm_tis_spi_transfer_data("first addr byte", byte);
+ trace_tpm_tis_spi_transfer_addr("reg_addr", spist->reg_addr);
+ break;
+ case 2: /* 2nd address byte */
+ spist->reg_addr |= byte << 8;
+ trace_tpm_tis_spi_transfer_data("second addr byte", byte);
+ trace_tpm_tis_spi_transfer_addr("reg_addr", spist->reg_addr);
+ break;
+ case 3: /* 3rd address byte */
+ spist->reg_addr |= byte;
+ trace_tpm_tis_spi_transfer_data("third addr byte", byte);
+ trace_tpm_tis_spi_transfer_addr("reg_addr", spist->reg_addr);
+ break;
+ default: /* data bytes */
+ if (spist->wait_state_cnt < 4) {
+ spist->wait_state_cnt++;
+ if (spist->wait_state_cnt == 4) {
+ trace_tpm_tis_spi_transfer_data("wait complete, count",
+ spist->wait_state_cnt);
+ rx = rx | (0x01 << (24 - offset * 8));
+ return rx;
+ } else {
+ trace_tpm_tis_spi_transfer_data("in wait state, count",
+ spist->wait_state_cnt);
+ rx = 0;
+ }
+ } else {
+ index = spist->byte_offset - 4;
+ trace_tpm_tis_spi_transfer_data("index", index);
+ trace_tpm_tis_spi_transfer_data("data byte", byte);
+ trace_tpm_tis_spi_transfer_addr("reg_addr", spist->reg_addr);
+ if (index >= spist->xfer_size) {
+ /*
+ * SPI SSI framework limits both rx and tx
+ * to fixed 4-byte with each xfer
+ */
+ trace_tpm_tis_spi_transfer_event("index exceeds
xfer_size");
+ return rx;
+ }
+ tis_addr = spist->reg_addr + (index % 4);
+ if (spist->spi_state == SPI_STATE_WRITE) {
+ tpm_tis_spi_write(spist, tis_addr, byte);
+ } else {
+ byte = tpm_tis_spi_read(spist, tis_addr);
+ rx = rx | (byte << (24 - offset * 8));
+ trace_tpm_tis_spi_transfer_data("byte added to response",
+ byte);
+ trace_tpm_tis_spi_transfer_data("offset", offset);
+ }
+ }
+ break;
+ }
+ if ((spist->wait_state_cnt == 0) || (spist->wait_state_cnt == 4)) {
+ offset++;
+ spist->byte_offset++;
+ } else {
+ break;
+ }
+ }
+ return rx;
+}
+
+static int tpm_cs(SSIPeripheral *ss, bool select)
+{
+ TPMStateSPI *spist = TPM_TIS_SPI(ss);
+
+ if (select) {
+ spist->command = false;
+ spist->spi_state = SPI_STATE_IDLE;
+ } else {
+ spist->command = true;
+ }
+ return 0;
+}
+
+static void tpm_realize(SSIPeripheral *dev, Error **errp)
+{
+ TPMStateSPI *spist = TPM_TIS_SPI(dev);
+ TPMState *s = &spist->tpm_state;
+
+ if (!tpm_find()) {
+ error_setg(errp, "at most one TPM device is permitted");
+ return;
+ }
+
+ s->be_driver = qemu_find_tpm_be("tpm0");
+
+ if (!s->be_driver) {
+ error_setg(errp, "unable to find tpm backend device");
+ return;
+ }
+}
+
+static void tpm_tis_spi_class_init(ObjectClass *klass, void *data)
+{
+ DeviceClass *dc = DEVICE_CLASS(klass);
+ TPMIfClass *tc = TPM_IF_CLASS(klass);
+ SSIPeripheralClass *k = SSI_PERIPHERAL_CLASS(klass);
+
+ k->transfer = tpm_transfer;
+ k->realize = tpm_realize;
+ k->set_cs = tpm_cs;
+ k->cs_polarity = SSI_CS_LOW;
+
+ device_class_set_legacy_reset(dc, tpm_tis_spi_reset);
+ device_class_set_props(dc, tpm_tis_spi_properties);
+ set_bit(DEVICE_CATEGORY_MISC, dc->categories);
+
+ dc->desc = "SPI TPM";
+ dc->vmsd = &vmstate_tpm_tis_spi;
+
+ tc->model = TPM_MODEL_TPM_TIS;
+ tc->request_completed = tpm_tis_spi_request_completed;
+ tc->get_version = tpm_tis_spi_get_tpm_version;
+}
+
+static const TypeInfo tpm_tis_spi_info = {
+ .name = TYPE_TPM_TIS_SPI,
+ .parent = TYPE_SSI_PERIPHERAL,
+ .instance_size = sizeof(TPMStateSPI),
+ .class_init = tpm_tis_spi_class_init,
+ .interfaces = (InterfaceInfo[]) {
+ { TYPE_TPM_IF },
+ { }
+ }
+};
+
+static void tpm_tis_spi_register_types(void)
+{
+ type_register_static(&tpm_tis_spi_info);
+}
+
+type_init(tpm_tis_spi_register_types)
diff --git a/hw/tpm/Kconfig b/hw/tpm/Kconfig
index a46663288c..5951c225cc 100644
--- a/hw/tpm/Kconfig
+++ b/hw/tpm/Kconfig
@@ -5,6 +5,12 @@ config TPM_TIS_I2C
select I2C
select TPM_TIS
+config TPM_TIS_SPI
+ bool
+ depends on TPM
+ select TPM_BACKEND
+ select TPM_TIS
+
config TPM_TIS_ISA
bool
depends on TPM && ISA_BUS
diff --git a/hw/tpm/meson.build b/hw/tpm/meson.build
index 6968e60b3f..e03cfb11b9 100644
--- a/hw/tpm/meson.build
+++ b/hw/tpm/meson.build
@@ -2,6 +2,7 @@ system_ss.add(when: 'CONFIG_TPM_TIS', if_true:
files('tpm_tis_common.c'))
system_ss.add(when: 'CONFIG_TPM_TIS_ISA', if_true: files('tpm_tis_isa.c'))
system_ss.add(when: 'CONFIG_TPM_TIS_SYSBUS', if_true:
files('tpm_tis_sysbus.c'))
system_ss.add(when: 'CONFIG_TPM_TIS_I2C', if_true: files('tpm_tis_i2c.c'))
+system_ss.add(when: 'CONFIG_TPM_TIS_SPI', if_true: files('tpm_tis_spi.c'))
system_ss.add(when: 'CONFIG_TPM_CRB', if_true: files('tpm_crb.c'))
system_ss.add(when: 'CONFIG_TPM_TIS', if_true: files('tpm_ppi.c'))
system_ss.add(when: 'CONFIG_TPM_CRB', if_true: files('tpm_ppi.c'))
diff --git a/hw/tpm/trace-events b/hw/tpm/trace-events
index fa882dfefe..0324ceb6d0 100644
--- a/hw/tpm/trace-events
+++ b/hw/tpm/trace-events
@@ -42,3 +42,10 @@ tpm_tis_i2c_recv(uint8_t data) "TPM I2C read: 0x%X"
tpm_tis_i2c_send(uint8_t data) "TPM I2C write: 0x%X"
tpm_tis_i2c_event(const char *event) "TPM I2C event: %s"
tpm_tis_i2c_send_reg(const char *name, int reg) "TPM I2C write register:
%s(0x%X)"
+
+# tpm_tis_spi.c
+tpm_tis_spi_write(uint32_t addr, uint8_t val) "TPM SPI write - addr:0x%08X
0x%02x"
+tpm_tis_spi_read(uint32_t addr, uint8_t val) "TPM SPI read - addr:0x%08X
0x%02x"
+tpm_tis_spi_transfer_event(const char *event) "TPM SPI XFER event: %s"
+tpm_tis_spi_transfer_data(const char *name, uint8_t val) "TPM SPI XFER: %s =
0x%02x"
+tpm_tis_spi_transfer_addr(const char *name, uint32_t addr) "TPM SPI XFER: %s =
0x%08x"
--
2.39.5