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Enable vTPM 2.0 for the IBM vTPM driver

PATCH Superseded Stefan Berger 2 participants 5 messages Feb 27, 2020 – Feb 28, 2020

Subsystems (3)
PowerPC Keys-trusted TPM device driver

v4 of 7 Superseded Latest is v7 →

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Stefan Berger

author
#0 lore raw

v4 cover Enable vTPM 2.0 for the IBM vTPM driver

From: Stefan Berger <[email protected]>

QEMU 5.0 will support the PAPR vTPM device model for TPM 1.2 and TPM 2.0. This series of patches enables vTPM 2.0 support for the IBM vTPM driver.

Regards,
Stefan

- v3->v4:
- Dropped patch 3; getting command code attributes table in IBM driver

- v2->v3:
- Added fixes tag to patch 2/4; the race seems to have existed since the driver was first added
- Renamed tpm2_init to tpm2_init_commands in 3/4

- v1->v2:
- Addressed comments to v1; added patch 3 to handle case when TPM_OPS_AUTO_STARTUP is not set

Stefan Berger (3):
tpm: of: Handle IBM,vtpm20 case when getting log parameters
tpm: ibmvtpm: Wait for buffer to be set before proceeding
tpm: ibmvtpm: Add support for TPM 2

 drivers/char/tpm/eventlog/of.c |  8 +++++++-
 drivers/char/tpm/tpm.h         |  1 +
 drivers/char/tpm/tpm2-cmd.c    |  2 +-
 drivers/char/tpm/tpm_ibmvtpm.c | 15 +++++++++++++++
 drivers/char/tpm/tpm_ibmvtpm.h |  1 +
 5 files changed, 25 insertions(+), 2 deletions(-)
Signature · 1 line
2.23.0
author
#1 lore raw

PATCH v4 1/3 tpm: of: Handle IBM,vtpm20 case when getting log parameters

From: Stefan Berger <[email protected]>

A vTPM 2.0 is identified by 'IBM,vtpm20' in the 'compatible' node in the device tree. Handle it in the same way as 'IBM,vtpm'.

The vTPM 2.0's log is written in little endian format so that for this aspect we can rely on existing code.

Signed-off-by Stefan Berger <[email protected]>
Acked-by Jarkko Sakkinen <[email protected]>
---
 drivers/char/tpm/eventlog/of.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)
drivers/char/tpm/eventlog/of.c +7 -1
index af347c190819..a31a625ad44e 100644
@@ -17,6 +17,12 @@
 #include "../tpm.h"
 #include "common.h"
 
+static const char * const compatibles[] = {
+	"IBM,vtpm",
+	"IBM,vtpm20",
+	NULL
+};
+
 int tpm_read_log_of(struct tpm_chip *chip)
 {
 	struct device_node *np;

@@ -51,7 +57,7 @@ int tpm_read_log_of(struct tpm_chip *chip)
 	 * endian format. For this reason, vtpm doesn't need conversion
 	 * but physical tpm needs the conversion.
 	 */
-	if (of_property_match_string(np, "compatible", "IBM,vtpm") < 0) {
+	if (!of_device_compatible_match(np, compatibles)) {
 		size = be32_to_cpup((__force __be32 *)sizep);
 		base = be64_to_cpup((__force __be64 *)basep);
 	} else {
Signature · 1 line
2.23.0
author
#2 lore raw

PATCH v4 2/3 tpm: ibmvtpm: Wait for buffer to be set before proceeding

In reply to Stefan Berger

From: Stefan Berger <[email protected]>

Synchronize with the results from the CRQs before continuing with the initialization. This avoids trying to send TPM commands while the rtce buffer has not been allocated, yet.

This patch fixes an existing race condition that may occurr if the hypervisor does not quickly respond to the VTPM_GET_RTCE_BUFFER_SIZE request sent during initialization and therefore the ibmvtpm->rtce_buf has not been allocated at the time the first TPM command is sent.

Fixes 132f76294744 ("Add new device driver to support IBM vTPM")
Signed-off-by Stefan Berger <[email protected]>
---
 drivers/char/tpm/tpm_ibmvtpm.c | 9 +++++++++
 drivers/char/tpm/tpm_ibmvtpm.h | 1 +
 2 files changed, 10 insertions(+)
drivers/char/tpm/tpm_ibmvtpm.c +9 -0
index 78cc52690177..eee566eddb35 100644
@@ -571,6 +571,7 @@ static irqreturn_t ibmvtpm_interrupt(int irq, void *vtpm_instance)
 	 */
 	while ((crq = ibmvtpm_crq_get_next(ibmvtpm)) != NULL) {
 		ibmvtpm_crq_process(crq, ibmvtpm);
+		wake_up_interruptible(&ibmvtpm->crq_queue.wq);
 		crq->valid = 0;
 		smp_wmb();
 	}

@@ -618,6 +619,7 @@ static int tpm_ibmvtpm_probe(struct vio_dev *vio_dev,
 	}
 
 	crq_q->num_entry = CRQ_RES_BUF_SIZE / sizeof(*crq_q->crq_addr);
+	init_waitqueue_head(&crq_q->wq);
 	ibmvtpm->crq_dma_handle = dma_map_single(dev, crq_q->crq_addr,
 						 CRQ_RES_BUF_SIZE,
 						 DMA_BIDIRECTIONAL);

@@ -670,6 +672,13 @@ static int tpm_ibmvtpm_probe(struct vio_dev *vio_dev,
 	if (rc)
 		goto init_irq_cleanup;
 
+	if (!wait_event_timeout(ibmvtpm->crq_queue.wq,
+				ibmvtpm->rtce_buf != NULL,
+				HZ)) {
+		dev_err(dev, "Initialization failed\n");
+		goto init_irq_cleanup;
+	}
+
 	return tpm_chip_register(chip);
 init_irq_cleanup:
 	do {
drivers/char/tpm/tpm_ibmvtpm.h +1 -0
index 7983f1a33267..b92aa7d3e93e 100644
@@ -26,6 +26,7 @@ struct ibmvtpm_crq_queue {
 	struct ibmvtpm_crq *crq_addr;
 	u32 index;
 	u32 num_entry;
+	wait_queue_head_t wq;
 };
 
 struct ibmvtpm_dev {
Signature · 1 line
2.23.0
author
#3 lore raw

PATCH v4 3/3 tpm: ibmvtpm: Add support for TPM 2

In reply to Stefan Berger

From: Stefan Berger <[email protected]>

Support TPM 2 in the IBM vTPM driver. The hypervisor tells us what version of TPM is connected through the vio_device_id.

In case a TPM 2 is found, we set the TPM_CHIP_FLAG_TPM2 flag and get the command codes attributes table. The driver does not need the timeouts and durations, though.

Signed-off-by Stefan Berger <[email protected]>
---
 drivers/char/tpm/tpm.h         | 1 +
 drivers/char/tpm/tpm2-cmd.c    | 2 +-
 drivers/char/tpm/tpm_ibmvtpm.c | 6 ++++++
 3 files changed, 8 insertions(+), 1 deletion(-)
drivers/char/tpm/tpm.h +1 -0
index 5620747da0cf..ad55c9824338 100644
@@ -226,6 +226,7 @@ int tpm2_auto_startup(struct tpm_chip *chip);
 void tpm2_shutdown(struct tpm_chip *chip, u16 shutdown_type);
 unsigned long tpm2_calc_ordinal_duration(struct tpm_chip *chip, u32 ordinal);
 int tpm2_probe(struct tpm_chip *chip);
+int tpm2_get_cc_attrs_tbl(struct tpm_chip *chip);
 int tpm2_find_cc(struct tpm_chip *chip, u32 cc);
 int tpm2_init_space(struct tpm_space *space);
 void tpm2_del_space(struct tpm_chip *chip, struct tpm_space *space);
drivers/char/tpm/tpm2-cmd.c +1 -1
index 13696deceae8..b6a0ee6bb03a 100644
@@ -613,7 +613,7 @@ ssize_t tpm2_get_pcr_allocation(struct tpm_chip *chip)
 	return rc;
 }
 
-static int tpm2_get_cc_attrs_tbl(struct tpm_chip *chip)
+int tpm2_get_cc_attrs_tbl(struct tpm_chip *chip)
 {
 	struct tpm_buf buf;
 	u32 nr_commands;
drivers/char/tpm/tpm_ibmvtpm.c +6 -0
index eee566eddb35..b6e61691a943 100644
@@ -29,6 +29,7 @@ static const char tpm_ibmvtpm_driver_name[] = "tpm_ibmvtpm";
 
 static const struct vio_device_id tpm_ibmvtpm_device_table[] = {
 	{ "IBM,vtpm", "IBM,vtpm"},
+	{ "IBM,vtpm", "IBM,vtpm20"},
 	{ "", "" }
 };
 MODULE_DEVICE_TABLE(vio, tpm_ibmvtpm_device_table);

@@ -672,6 +673,11 @@ static int tpm_ibmvtpm_probe(struct vio_dev *vio_dev,
 	if (rc)
 		goto init_irq_cleanup;
 
+	if (!strcmp(id->compat, "IBM,vtpm20")) {
+		chip->flags |= TPM_CHIP_FLAG_TPM2;
+		tpm2_get_cc_attrs_tbl(chip);
+	}
+
 	if (!wait_event_timeout(ibmvtpm->crq_queue.wq,
 				ibmvtpm->rtce_buf != NULL,
 				HZ)) {
Signature · 1 line
2.23.0
#4 lore raw
In reply to Stefan Berger

Jarkko,

 please ignore v4. Have a look at v5.

  Stefan

Quoted 34 lines

From: Stefan Berger <[email protected]>

QEMU 5.0 will support the PAPR vTPM device model for TPM 1.2 and TPM 2.0. This series of patches enables vTPM 2.0 support for the IBM vTPM driver.

Regards,
Stefan

- v3->v4:
- Dropped patch 3; getting command code attributes table in IBM driver

- v2->v3:
- Added fixes tag to patch 2/4; the race seems to have existed since the driver was first added
- Renamed tpm2_init to tpm2_init_commands in 3/4

- v1->v2:
- Addressed comments to v1; added patch 3 to handle case when TPM_OPS_AUTO_STARTUP is not set

Stefan Berger (3):
tpm: of: Handle IBM,vtpm20 case when getting log parameters
tpm: ibmvtpm: Wait for buffer to be set before proceeding
tpm: ibmvtpm: Add support for TPM 2

  drivers/char/tpm/eventlog/of.c |  8 +++++++-
  drivers/char/tpm/tpm.h         |  1 +
  drivers/char/tpm/tpm2-cmd.c    |  2 +-
  drivers/char/tpm/tpm_ibmvtpm.c | 15 +++++++++++++++
  drivers/char/tpm/tpm_ibmvtpm.h |  1 +
  5 files changed, 25 insertions(+), 2 deletions(-)