| Message ID | 20190530152758.16628-2-sashal@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | fTPM: firmware TPM running in TEE | expand |
On Thu, 30 May 2019 at 20:58, Sasha Levin <sashal@kernel.org> wrote: > > This patch adds support for a software-only implementation of a TPM > running in TEE. > > There is extensive documentation of the design here: > https://www.microsoft.com/en-us/research/publication/ftpm-software-implementation-tpm-chip/ . > > As well as reference code for the firmware available here: > https://github.com/Microsoft/ms-tpm-20-ref/tree/master/Samples/ARM32-FirmwareTPM > > Signed-off-by: Thirupathaiah Annapureddy <thiruan@microsoft.com> > Signed-off-by: Sasha Levin <sashal@kernel.org> > --- > drivers/char/tpm/Kconfig | 5 + > drivers/char/tpm/Makefile | 1 + > drivers/char/tpm/tpm_ftpm_tee.c | 380 ++++++++++++++++++++++++++++++++ > drivers/char/tpm/tpm_ftpm_tee.h | 40 ++++ > 4 files changed, 426 insertions(+) > create mode 100644 drivers/char/tpm/tpm_ftpm_tee.c > create mode 100644 drivers/char/tpm/tpm_ftpm_tee.h > > diff --git a/drivers/char/tpm/Kconfig b/drivers/char/tpm/Kconfig > index f3e4bc490cf05..8bc9a56cade14 100644 > --- a/drivers/char/tpm/Kconfig > +++ b/drivers/char/tpm/Kconfig > @@ -163,6 +163,11 @@ config TCG_VTPM_PROXY > /dev/vtpmX and a server-side file descriptor on which the vTPM > can receive commands. > > +config TCG_FTPM_TEE > + tristate "TEE based fTPM Interface" > + depends on TEE && OPTEE > + ---help--- > + This driver proxies for fTPM running in TEE > > source "drivers/char/tpm/st33zp24/Kconfig" > endif # TCG_TPM > diff --git a/drivers/char/tpm/Makefile b/drivers/char/tpm/Makefile > index a01c4cab902a6..c354cdff9c625 100644 > --- a/drivers/char/tpm/Makefile > +++ b/drivers/char/tpm/Makefile > @@ -33,3 +33,4 @@ obj-$(CONFIG_TCG_TIS_ST33ZP24) += st33zp24/ > obj-$(CONFIG_TCG_XEN) += xen-tpmfront.o > obj-$(CONFIG_TCG_CRB) += tpm_crb.o > obj-$(CONFIG_TCG_VTPM_PROXY) += tpm_vtpm_proxy.o > +obj-$(CONFIG_TCG_FTPM_TEE) += tpm_ftpm_tee.o > diff --git a/drivers/char/tpm/tpm_ftpm_tee.c b/drivers/char/tpm/tpm_ftpm_tee.c > new file mode 100644 > index 0000000000000..f926b1287988b > --- /dev/null > +++ b/drivers/char/tpm/tpm_ftpm_tee.c > @@ -0,0 +1,380 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Copyright (C) Microsoft Corporation > + * > + * Implements a firmware TPM as described here: > + * https://www.microsoft.com/en-us/research/publication/ftpm-software-implementation-tpm-chip/ > + * > + * A reference implementation is available here: > + * https://github.com/microsoft/ms-tpm-20-ref/tree/master/Samples/ARM32-FirmwareTPM/optee_ta/fTPM > + */ > + > +#include <linux/acpi.h> > +#include <linux/of.h> > +#include <linux/of_platform.h> > +#include <linux/platform_device.h> > +#include <linux/tee_drv.h> > +#include <linux/tpm.h> > +#include <linux/uuid.h> > + > +#include "tpm.h" > +#include "tpm_ftpm_tee.h" > + > +#define DRIVER_NAME "ftpm-tee" > + > +/* > + * TA_FTPM_UUID: BC50D971-D4C9-42C4-82CB-343FB7F37896 > + * > + * Randomly generated, and must correspond to the GUID on the TA side. > + * Defined here in the reference implementation: > + * https://github.com/microsoft/ms-tpm-20-ref/blob/master/Samples/ARM32-FirmwareTPM/optee_ta/fTPM/include/fTPM.h#L42 > + */ > + > +static const uuid_t ftpm_ta_uuid = > + UUID_INIT(0xBC50D971, 0xD4C9, 0x42C4, > + 0x82, 0xCB, 0x34, 0x3F, 0xB7, 0xF3, 0x78, 0x96); > + > +/** > + * ftpm_tee_tpm_op_recv - retrieve fTPM response. > + * > + * @chip: the tpm_chip description as specified in driver/char/tpm/tpm.h. > + * @buf: the buffer to store data. > + * @count: the number of bytes to read. > + * > + * Return: > + * In case of success the number of bytes received. > + * On failure, -errno. > + */ > +static int ftpm_tee_tpm_op_recv(struct tpm_chip *chip, u8 *buf, size_t count) > +{ > + struct ftpm_tee_private *pvt_data = dev_get_drvdata(chip->dev.parent); > + size_t len; > + > + len = pvt_data->resp_len; > + if (count < len) { > + dev_err(&chip->dev, > + "%s:Invalid size in recv: count=%zd, resp_len=%zd\n", > + __func__, count, len); > + return -EIO; > + } > + > + memcpy(buf, pvt_data->resp_buf, len); > + pvt_data->resp_len = 0; > + > + return len; > +} > + > +/** > + * ftpm_tee_tpm_op_send - send TPM commands through the TEE shared memory. > + * > + * @chip: the tpm_chip description as specified in driver/char/tpm/tpm.h > + * @buf: the buffer to send. > + * @len: the number of bytes to send. > + * > + * Return: > + * In case of success, returns 0. > + * On failure, -errno > + */ > +static int ftpm_tee_tpm_op_send(struct tpm_chip *chip, u8 *buf, size_t len) > +{ > + struct ftpm_tee_private *pvt_data = dev_get_drvdata(chip->dev.parent); > + size_t resp_len; > + int rc; > + u8 *temp_buf; > + struct tpm_header *resp_header; > + struct tee_ioctl_invoke_arg transceive_args; > + struct tee_param command_params[4]; > + struct tee_shm *shm = pvt_data->shm; > + > + if (len > MAX_COMMAND_SIZE) { > + dev_err(&chip->dev, > + "%s:len=%zd exceeds MAX_COMMAND_SIZE supported by fTPM TA\n", > + __func__, len); > + return -EIO; > + } > + > + memset(&transceive_args, 0, sizeof(transceive_args)); > + memset(command_params, 0, sizeof(command_params)); > + pvt_data->resp_len = 0; > + > + /* Invoke FTPM_OPTEE_TA_SUBMIT_COMMAND function of fTPM TA */ > + transceive_args = (struct tee_ioctl_invoke_arg) { > + .func = FTPM_OPTEE_TA_SUBMIT_COMMAND, > + .session = pvt_data->session, > + .num_params = 4, > + }; > + > + /* Fill FTPM_OPTEE_TA_SUBMIT_COMMAND parameters */ > + command_params[0] = (struct tee_param) { > + .attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT, > + .u.memref = { > + .shm = shm, > + .size = len, > + .shm_offs = 0, > + }, > + }; > + > + temp_buf = tee_shm_get_va(shm, 0); > + if (IS_ERR(temp_buf)) { > + dev_err(&chip->dev, "%s:tee_shm_get_va failed for transmit\n", > + __func__); > + return PTR_ERR(temp_buf); > + } > + memset(temp_buf, 0, (MAX_COMMAND_SIZE + MAX_RESPONSE_SIZE)); > + > + memcpy(temp_buf, buf, len); > + > + command_params[1] = (struct tee_param) { > + .attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT, > + .u.memref = { > + .shm = shm, > + .size = MAX_RESPONSE_SIZE, > + .shm_offs = MAX_COMMAND_SIZE, > + }, > + }; > + > + rc = tee_client_invoke_func(pvt_data->ctx, &transceive_args, > + command_params); > + if ((rc < 0) || (transceive_args.ret != 0)) { > + dev_err(&chip->dev, "%s:SUBMIT_COMMAND invoke error: 0x%x\n", > + __func__, transceive_args.ret); > + return (rc < 0) ? rc : transceive_args.ret; > + } > + > + temp_buf = tee_shm_get_va(shm, command_params[1].u.memref.shm_offs); > + if (IS_ERR(temp_buf)) { > + dev_err(&chip->dev, "%s:tee_shm_get_va failed for receive\n", > + __func__); > + return PTR_ERR(temp_buf); > + } > + > + resp_header = (struct tpm_header *)temp_buf; > + resp_len = be32_to_cpu(resp_header->length); > + > + /* sanity check resp_len */ > + if (resp_len < TPM_HEADER_SIZE) { > + dev_err(&chip->dev, "%s:tpm response header too small\n", > + __func__); > + return -EIO; > + } > + if (resp_len > MAX_RESPONSE_SIZE) { > + dev_err(&chip->dev, > + "%s:resp_len=%zd exceeds MAX_RESPONSE_SIZE\n", > + __func__, resp_len); > + return -EIO; > + } > + > + /* sanity checks look good, cache the response */ > + memcpy(pvt_data->resp_buf, temp_buf, resp_len); > + pvt_data->resp_len = resp_len; > + > + return 0; > +} > + > +static void ftpm_tee_tpm_op_cancel(struct tpm_chip *chip) > +{ > + /* not supported */ > +} > + > +static u8 ftpm_tee_tpm_op_status(struct tpm_chip *chip) > +{ > + return 0; > +} > + > +static bool ftpm_tee_tpm_req_canceled(struct tpm_chip *chip, u8 status) > +{ > + return 0; > +} > + > +static const struct tpm_class_ops ftpm_tee_tpm_ops = { > + .flags = TPM_OPS_AUTO_STARTUP, > + .recv = ftpm_tee_tpm_op_recv, > + .send = ftpm_tee_tpm_op_send, > + .cancel = ftpm_tee_tpm_op_cancel, > + .status = ftpm_tee_tpm_op_status, > + .req_complete_mask = 0, > + .req_complete_val = 0, > + .req_canceled = ftpm_tee_tpm_req_canceled, > +}; > + > +/* > + * Check whether this driver supports the fTPM TA in the TEE instance > + * represented by the params (ver/data) to this function. > + */ > +static int ftpm_tee_match(struct tee_ioctl_version_data *ver, const void *data) > +{ > + /* > + * Currently this driver only support GP Complaint OPTEE based fTPM TA > + */ > + if ((ver->impl_id == TEE_IMPL_ID_OPTEE) && > + (ver->gen_caps & TEE_GEN_CAP_GP)) > + return 1; > + else > + return 0; > +} > + > +/* > + * Undo what has been done in ftpm_tee_probe > + */ > +static void ftpm_tee_deinit(struct ftpm_tee_private *pvt_data) > +{ > + /* Release the chip */ > + tpm_chip_unregister(pvt_data->chip); > + > + /* frees chip */ > + if (pvt_data->chip) > + put_device(&pvt_data->chip->dev); > + > + if (pvt_data->ctx) { > + /* Free the shared memory pool */ > + tee_shm_free(pvt_data->shm); > + > + /* close the existing session with fTPM TA*/ > + tee_client_close_session(pvt_data->ctx, pvt_data->session); > + > + /* close the context with TEE driver */ > + tee_client_close_context(pvt_data->ctx); > + } > + > + /* memory allocated with devm_kzalloc() is freed automatically */ > +} > + > +/** > + * ftpm_tee_probe - initialize the fTPM > + * @pdev: the platform_device description. > + * > + * Return: > + * On success, 0. On failure, -errno. > + */ > +static int ftpm_tee_probe(struct platform_device *pdev) > +{ > + int rc; > + struct tpm_chip *chip; > + struct device *dev = &pdev->dev; > + struct ftpm_tee_private *pvt_data = NULL; > + struct tee_ioctl_open_session_arg sess_arg; > + > + pvt_data = devm_kzalloc(dev, sizeof(struct ftpm_tee_private), > + GFP_KERNEL); > + if (!pvt_data) > + return -ENOMEM; > + > + dev_set_drvdata(dev, pvt_data); > + > + /* Open context with TEE driver */ > + pvt_data->ctx = tee_client_open_context(NULL, ftpm_tee_match, NULL, > + NULL); > + if (IS_ERR(pvt_data->ctx)) { > + dev_err(dev, "%s:tee_client_open_context failed\n", __func__); Is this well tested? I see this misleading error multiple times as follows although TEE driver works pretty well. Module built with "CONFIG_TCG_FTPM_TEE=y" [ 1.436878] ftpm-tee tpm@0: ftpm_tee_probe:tee_client_open_context failed [ 1.509471] ftpm-tee tpm@0: ftpm_tee_probe:tee_client_open_context failed [ 1.517268] ftpm-tee tpm@0: ftpm_tee_probe:tee_client_open_context failed [ 1.525596] ftpm-tee tpm@0: ftpm_tee_probe:tee_client_open_context failed -Sumit > + return -EPROBE_DEFER; > + } > + > + /* Open a session with fTPM TA */ > + memset(&sess_arg, 0, sizeof(sess_arg)); > + memcpy(sess_arg.uuid, ftpm_ta_uuid.b, TEE_IOCTL_UUID_LEN); > + sess_arg.clnt_login = TEE_IOCTL_LOGIN_PUBLIC; > + sess_arg.num_params = 0; > + > + rc = tee_client_open_session(pvt_data->ctx, &sess_arg, NULL); > + if ((rc < 0) || (sess_arg.ret != 0)) { > + dev_err(dev, "%s:tee_client_open_session failed, err=%x\n", > + __func__, sess_arg.ret); > + rc = -EINVAL; > + goto out_tee_session; > + } > + pvt_data->session = sess_arg.session; > + > + /* Allocate dynamic shared memory with fTPM TA */ > + pvt_data->shm = tee_shm_alloc(pvt_data->ctx, > + (MAX_COMMAND_SIZE + MAX_RESPONSE_SIZE), > + TEE_SHM_MAPPED | TEE_SHM_DMA_BUF); > + if (IS_ERR(pvt_data->shm)) { > + dev_err(dev, "%s:tee_shm_alloc failed\n", __func__); > + rc = -ENOMEM; > + goto out_shm_alloc; > + } > + > + /* Allocate new struct tpm_chip instance */ > + chip = tpm_chip_alloc(dev, &ftpm_tee_tpm_ops); > + if (IS_ERR(chip)) { > + dev_err(dev, "%s:tpm_chip_alloc failed\n", __func__); > + rc = PTR_ERR(chip); > + goto out_chip_alloc; > + } > + > + pvt_data->chip = chip; > + pvt_data->chip->flags |= TPM_CHIP_FLAG_TPM2; > + > + /* Create a character device for the fTPM */ > + rc = tpm_chip_register(pvt_data->chip); > + if (rc) { > + dev_err(dev, "%s:tpm_chip_register failed with rc=%d\n", > + __func__, rc); > + goto out_chip; > + } > + > + return 0; > + > +out_chip: > + put_device(&pvt_data->chip->dev); > +out_chip_alloc: > + tee_shm_free(pvt_data->shm); > +out_shm_alloc: > + tee_client_close_session(pvt_data->ctx, pvt_data->session); > +out_tee_session: > + tee_client_close_context(pvt_data->ctx); > + > + return rc; > +} > + > +/** > + * ftpm_tee_remove - remove the TPM device > + * @pdev: the platform_device description. > + * > + * Return: > + * 0 in case of success. > + */ > +static int ftpm_tee_remove(struct platform_device *pdev) > +{ > + struct ftpm_tee_private *pvt_data = dev_get_drvdata(&pdev->dev); > + > + /* Release the chip */ > + tpm_chip_unregister(pvt_data->chip); > + > + /* frees chip */ > + put_device(&pvt_data->chip->dev); > + > + /* Free the shared memory pool */ > + tee_shm_free(pvt_data->shm); > + > + /* close the existing session with fTPM TA*/ > + tee_client_close_session(pvt_data->ctx, pvt_data->session); > + > + /* close the context with TEE driver */ > + tee_client_close_context(pvt_data->ctx); > + > + /* memory allocated with devm_kzalloc() is freed automatically */ > + > + return 0; > +} > + > +static const struct of_device_id of_ftpm_tee_ids[] = { > + { .compatible = "microsoft,ftpm" }, > + { } > +}; > +MODULE_DEVICE_TABLE(of, of_ftpm_tee_ids); > + > +static struct platform_driver ftpm_tee_driver = { > + .driver = { > + .name = DRIVER_NAME, > + .of_match_table = of_match_ptr(of_ftpm_tee_ids), > + }, > + .probe = ftpm_tee_probe, > + .remove = ftpm_tee_remove, > +}; > + > +module_platform_driver(ftpm_tee_driver); > + > +MODULE_AUTHOR("Thirupathaiah Annapureddy <thiruan@microsoft.com>"); > +MODULE_DESCRIPTION("TPM Driver for fTPM TA in TEE"); > +MODULE_LICENSE("GPL v2"); > diff --git a/drivers/char/tpm/tpm_ftpm_tee.h b/drivers/char/tpm/tpm_ftpm_tee.h > new file mode 100644 > index 0000000000000..b09ee7be45459 > --- /dev/null > +++ b/drivers/char/tpm/tpm_ftpm_tee.h > @@ -0,0 +1,40 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > +/* > + * Copyright (C) Microsoft Corporation > + */ > + > +#ifndef __TPM_FTPM_TEE_H__ > +#define __TPM_FTPM_TEE_H__ > + > +#include <linux/tee_drv.h> > +#include <linux/tpm.h> > +#include <linux/uuid.h> > + > +/* The TAFs ID implemented in this TA */ > +#define FTPM_OPTEE_TA_SUBMIT_COMMAND (0) > +#define FTPM_OPTEE_TA_EMULATE_PPI (1) > + > +/* max. buffer size supported by fTPM */ > +#define MAX_COMMAND_SIZE 4096 > +#define MAX_RESPONSE_SIZE 4096 > + > +/** > + * struct ftpm_tee_private - fTPM's private data > + * @chip: struct tpm_chip instance registered with tpm framework. > + * @state: internal state > + * @session: fTPM TA session identifier. > + * @resp_len: cached response buffer length. > + * @resp_buf: cached response buffer. > + * @ctx: TEE context handler. > + * @shm: Memory pool shared with fTPM TA in TEE. > + */ > +struct ftpm_tee_private { > + struct tpm_chip *chip; > + u32 session; > + size_t resp_len; > + u8 resp_buf[MAX_RESPONSE_SIZE]; > + struct tee_context *ctx; > + struct tee_shm *shm; > +}; > + > +#endif /* __TPM_FTPM_TEE_H__ */ > -- > 2.20.1 >
On Tue, Jun 04, 2019 at 11:45:52AM +0530, Sumit Garg wrote: >On Thu, 30 May 2019 at 20:58, Sasha Levin <sashal@kernel.org> wrote: >> + /* Open context with TEE driver */ >> + pvt_data->ctx = tee_client_open_context(NULL, ftpm_tee_match, NULL, >> + NULL); >> + if (IS_ERR(pvt_data->ctx)) { >> + dev_err(dev, "%s:tee_client_open_context failed\n", __func__); > >Is this well tested? I see this misleading error multiple times as >follows although TEE driver works pretty well. Yes, this was all functionally tested. Why is this error message misleading? I'd be happy to fix it. >Module built with "CONFIG_TCG_FTPM_TEE=y" > >[ 1.436878] ftpm-tee tpm@0: ftpm_tee_probe:tee_client_open_context failed >[ 1.509471] ftpm-tee tpm@0: ftpm_tee_probe:tee_client_open_context failed >[ 1.517268] ftpm-tee tpm@0: ftpm_tee_probe:tee_client_open_context failed >[ 1.525596] ftpm-tee tpm@0: ftpm_tee_probe:tee_client_open_context failed Does the TEE have the fTPM implementation and such? Could you provide details about your testing environment (hardware, fTPM verions, etc)? -- Thanks, Sasha
On Wed, 5 Jun 2019 at 01:39, Sasha Levin <sashal@kernel.org> wrote: > > On Tue, Jun 04, 2019 at 11:45:52AM +0530, Sumit Garg wrote: > >On Thu, 30 May 2019 at 20:58, Sasha Levin <sashal@kernel.org> wrote: > >> + /* Open context with TEE driver */ > >> + pvt_data->ctx = tee_client_open_context(NULL, ftpm_tee_match, NULL, > >> + NULL); > >> + if (IS_ERR(pvt_data->ctx)) { > >> + dev_err(dev, "%s:tee_client_open_context failed\n", __func__); > > > >Is this well tested? I see this misleading error multiple times as > >follows although TEE driver works pretty well. > > Yes, this was all functionally tested. Can you share your build instructions and testing approach? > > Why is this error message misleading? I'd be happy to fix it. IIUC, here you are trying to resolve dependency with OP-TEE driver using "-EPROBE_DEFER". So user shouldn't be prompted with error messages until OP-TEE driver comes up. BTW, for me this OP-TEE driver dependency seems not to work, boot is simply stuck waiting for device. Probably the reason being this fTPM driver is a platform driver and OP-TEE NOT a platform driver. > > >Module built with "CONFIG_TCG_FTPM_TEE=y" > > > >[ 1.436878] ftpm-tee tpm@0: ftpm_tee_probe:tee_client_open_context failed > >[ 1.509471] ftpm-tee tpm@0: ftpm_tee_probe:tee_client_open_context failed > >[ 1.517268] ftpm-tee tpm@0: ftpm_tee_probe:tee_client_open_context failed > >[ 1.525596] ftpm-tee tpm@0: ftpm_tee_probe:tee_client_open_context failed > > Does the TEE have the fTPM implementation and such? Could you provide > details about your testing environment (hardware, fTPM verions, etc)? > I just did a sanity check on my arm64 machine (Developerbox), just adding following DT node and enabled CONFIG_TCG_FTPM_TEE=y: + tpm@0 { + compatible = "microsoft,ftpm"; + }; Basically with no fTPM TA, I expected the driver to fail during "tee_client_open_session()" call with TA not found error and boot should continue. But it fails during "tee_client_open_context()" which opens a context with OP-TEE driver and has nothing to do with fTPM TA. -Sumit > -- > Thanks, > Sasha
On Tue, Jun 04, 2019 at 11:45:52AM +0530, Sumit Garg wrote: > Is this well tested? I see this misleading error multiple times as > follows although TEE driver works pretty well. > > Module built with "CONFIG_TCG_FTPM_TEE=y" > > [ 1.436878] ftpm-tee tpm@0: ftpm_tee_probe:tee_client_open_context failed > [ 1.509471] ftpm-tee tpm@0: ftpm_tee_probe:tee_client_open_context failed > [ 1.517268] ftpm-tee tpm@0: ftpm_tee_probe:tee_client_open_context failed > [ 1.525596] ftpm-tee tpm@0: ftpm_tee_probe:tee_client_open_context failed > > -Sumit No testing done from my part. /Jarkko
On Wed, Jun 05, 2019 at 04:39:36PM +0530, Sumit Garg wrote: >On Wed, 5 Jun 2019 at 01:39, Sasha Levin <sashal@kernel.org> wrote: >> >> On Tue, Jun 04, 2019 at 11:45:52AM +0530, Sumit Garg wrote: >> >On Thu, 30 May 2019 at 20:58, Sasha Levin <sashal@kernel.org> wrote: >> >> + /* Open context with TEE driver */ >> >> + pvt_data->ctx = tee_client_open_context(NULL, ftpm_tee_match, NULL, >> >> + NULL); >> >> + if (IS_ERR(pvt_data->ctx)) { >> >> + dev_err(dev, "%s:tee_client_open_context failed\n", __func__); >> > >> >Is this well tested? I see this misleading error multiple times as >> >follows although TEE driver works pretty well. >> >> Yes, this was all functionally tested. > >Can you share your build instructions and testing approach? Yes: it looks like you got all the kernel bits, but not the firmware. There are instructions for it here: https://github.com/microsoft/ms-tpm-20-ref Once it's running, you can test it by running your favorite TPM usecases through /dev/tpm0. -- Thanks, Sasha
Hi Sasha, On Thu, Jun 13, 2019 at 01:11:41PM -0400, Sasha Levin wrote: > On Wed, Jun 05, 2019 at 04:39:36PM +0530, Sumit Garg wrote: > >On Wed, 5 Jun 2019 at 01:39, Sasha Levin <sashal@kernel.org> wrote: > >> > >>On Tue, Jun 04, 2019 at 11:45:52AM +0530, Sumit Garg wrote: > >>>On Thu, 30 May 2019 at 20:58, Sasha Levin <sashal@kernel.org> wrote: > >>>> + /* Open context with TEE driver */ > >>>> + pvt_data->ctx = tee_client_open_context(NULL, ftpm_tee_match, NULL, > >>>> + NULL); > >>>> + if (IS_ERR(pvt_data->ctx)) { > >>>> + dev_err(dev, "%s:tee_client_open_context failed\n", __func__); > >>> > >>>Is this well tested? I see this misleading error multiple times as > >>>follows although TEE driver works pretty well. > >> > >>Yes, this was all functionally tested. I did test as well with a DeveloperBox, i can confirm the driver is loading (but i have no fTPM support on the OP-TEE side for now) apalos@mule:~>sudo dmesg | grep optee [sudo] password for apalos: [ 5.035801] optee: probing for conduit method from DT. [ 5.041045] optee: revision 3.2 (53bf1c38) [ 5.041772] optee: initialized driver apalos@mule:~>sudo dmesg | grep tpm [ 5.000674] ftpm-tee tpm@0: ftpm_tee_probe:tee_client_open_context failed [ 5.101655] ftpm-tee tpm@0: ftpm_tee_probe:tee_client_open_session failed, err=ffff000c [ 5.109703] ftpm-tee: probe of tpm@0 failed with error -22 The error -22 is nice since the probe eventually failed (no fTPM support in secure world). Can we slightly change the 'ftpm_tee_probe:tee_client_open_context failed' and indicate this is not a real error since the probe gets deferred untill Secure world is alive? By the way there is *real* interest for this functionality. I expect to run it on a number of Arm boards once i get some free time. > >Can you share your build instructions and testing approach? > > Yes: it looks like you got all the kernel bits, but not the firmware. > There are instructions for it here: https://github.com/microsoft/ms-tpm-20-ref > > Once it's running, you can test it by running your favorite TPM usecases > through /dev/tpm0. > > -- > Thanks, > Sasha Thanks /Ilias
On Wed, 5 Jun 2019 at 16:39, Sumit Garg <sumit.garg@linaro.org> wrote: > > On Wed, 5 Jun 2019 at 01:39, Sasha Levin <sashal@kernel.org> wrote: > > > > On Tue, Jun 04, 2019 at 11:45:52AM +0530, Sumit Garg wrote: > > >On Thu, 30 May 2019 at 20:58, Sasha Levin <sashal@kernel.org> wrote: > > >> + /* Open context with TEE driver */ > > >> + pvt_data->ctx = tee_client_open_context(NULL, ftpm_tee_match, NULL, > > >> + NULL); > > >> + if (IS_ERR(pvt_data->ctx)) { > > >> + dev_err(dev, "%s:tee_client_open_context failed\n", __func__); > > > > > >Is this well tested? I see this misleading error multiple times as > > >follows although TEE driver works pretty well. > > > > Yes, this was all functionally tested. > > Can you share your build instructions and testing approach? > > > > > Why is this error message misleading? I'd be happy to fix it. > But still this message should be updated to represent correct status. Maybe something like: dev_warn(dev, "waiting for OP-TEE to be alive\n"); > IIUC, here you are trying to resolve dependency with OP-TEE driver > using "-EPROBE_DEFER". So user shouldn't be prompted with error > messages until OP-TEE driver comes up. > > BTW, for me this OP-TEE driver dependency seems not to work, boot is > simply stuck waiting for device. Probably the reason being this fTPM > driver is a platform driver and OP-TEE NOT a platform driver. > Apologies for the noise here. It works as expected. -Sumit > > > > >Module built with "CONFIG_TCG_FTPM_TEE=y" > > > > > >[ 1.436878] ftpm-tee tpm@0: ftpm_tee_probe:tee_client_open_context failed > > >[ 1.509471] ftpm-tee tpm@0: ftpm_tee_probe:tee_client_open_context failed > > >[ 1.517268] ftpm-tee tpm@0: ftpm_tee_probe:tee_client_open_context failed > > >[ 1.525596] ftpm-tee tpm@0: ftpm_tee_probe:tee_client_open_context failed > > > > Does the TEE have the fTPM implementation and such? Could you provide > > details about your testing environment (hardware, fTPM verions, etc)? > > > > I just did a sanity check on my arm64 machine (Developerbox), just > adding following DT node and enabled CONFIG_TCG_FTPM_TEE=y: > > + tpm@0 { > + compatible = "microsoft,ftpm"; > + }; > > Basically with no fTPM TA, I expected the driver to fail during > "tee_client_open_session()" call with TA not found error and boot > should continue. But it fails during "tee_client_open_context()" which > opens a context with OP-TEE driver and has nothing to do with fTPM TA. > > -Sumit > > > -- > > Thanks, > > Sasha
diff --git a/drivers/char/tpm/Kconfig b/drivers/char/tpm/Kconfig index f3e4bc490cf05..8bc9a56cade14 100644 --- a/drivers/char/tpm/Kconfig +++ b/drivers/char/tpm/Kconfig @@ -163,6 +163,11 @@ config TCG_VTPM_PROXY /dev/vtpmX and a server-side file descriptor on which the vTPM can receive commands. +config TCG_FTPM_TEE + tristate "TEE based fTPM Interface" + depends on TEE && OPTEE + ---help--- + This driver proxies for fTPM running in TEE source "drivers/char/tpm/st33zp24/Kconfig" endif # TCG_TPM diff --git a/drivers/char/tpm/Makefile b/drivers/char/tpm/Makefile index a01c4cab902a6..c354cdff9c625 100644 --- a/drivers/char/tpm/Makefile +++ b/drivers/char/tpm/Makefile @@ -33,3 +33,4 @@ obj-$(CONFIG_TCG_TIS_ST33ZP24) += st33zp24/ obj-$(CONFIG_TCG_XEN) += xen-tpmfront.o obj-$(CONFIG_TCG_CRB) += tpm_crb.o obj-$(CONFIG_TCG_VTPM_PROXY) += tpm_vtpm_proxy.o +obj-$(CONFIG_TCG_FTPM_TEE) += tpm_ftpm_tee.o diff --git a/drivers/char/tpm/tpm_ftpm_tee.c b/drivers/char/tpm/tpm_ftpm_tee.c new file mode 100644 index 0000000000000..f926b1287988b --- /dev/null +++ b/drivers/char/tpm/tpm_ftpm_tee.c @@ -0,0 +1,380 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) Microsoft Corporation + * + * Implements a firmware TPM as described here: + * https://www.microsoft.com/en-us/research/publication/ftpm-software-implementation-tpm-chip/ + * + * A reference implementation is available here: + * https://github.com/microsoft/ms-tpm-20-ref/tree/master/Samples/ARM32-FirmwareTPM/optee_ta/fTPM + */ + +#include <linux/acpi.h> +#include <linux/of.h> +#include <linux/of_platform.h> +#include <linux/platform_device.h> +#include <linux/tee_drv.h> +#include <linux/tpm.h> +#include <linux/uuid.h> + +#include "tpm.h" +#include "tpm_ftpm_tee.h" + +#define DRIVER_NAME "ftpm-tee" + +/* + * TA_FTPM_UUID: BC50D971-D4C9-42C4-82CB-343FB7F37896 + * + * Randomly generated, and must correspond to the GUID on the TA side. + * Defined here in the reference implementation: + * https://github.com/microsoft/ms-tpm-20-ref/blob/master/Samples/ARM32-FirmwareTPM/optee_ta/fTPM/include/fTPM.h#L42 + */ + +static const uuid_t ftpm_ta_uuid = + UUID_INIT(0xBC50D971, 0xD4C9, 0x42C4, + 0x82, 0xCB, 0x34, 0x3F, 0xB7, 0xF3, 0x78, 0x96); + +/** + * ftpm_tee_tpm_op_recv - retrieve fTPM response. + * + * @chip: the tpm_chip description as specified in driver/char/tpm/tpm.h. + * @buf: the buffer to store data. + * @count: the number of bytes to read. + * + * Return: + * In case of success the number of bytes received. + * On failure, -errno. + */ +static int ftpm_tee_tpm_op_recv(struct tpm_chip *chip, u8 *buf, size_t count) +{ + struct ftpm_tee_private *pvt_data = dev_get_drvdata(chip->dev.parent); + size_t len; + + len = pvt_data->resp_len; + if (count < len) { + dev_err(&chip->dev, + "%s:Invalid size in recv: count=%zd, resp_len=%zd\n", + __func__, count, len); + return -EIO; + } + + memcpy(buf, pvt_data->resp_buf, len); + pvt_data->resp_len = 0; + + return len; +} + +/** + * ftpm_tee_tpm_op_send - send TPM commands through the TEE shared memory. + * + * @chip: the tpm_chip description as specified in driver/char/tpm/tpm.h + * @buf: the buffer to send. + * @len: the number of bytes to send. + * + * Return: + * In case of success, returns 0. + * On failure, -errno + */ +static int ftpm_tee_tpm_op_send(struct tpm_chip *chip, u8 *buf, size_t len) +{ + struct ftpm_tee_private *pvt_data = dev_get_drvdata(chip->dev.parent); + size_t resp_len; + int rc; + u8 *temp_buf; + struct tpm_header *resp_header; + struct tee_ioctl_invoke_arg transceive_args; + struct tee_param command_params[4]; + struct tee_shm *shm = pvt_data->shm; + + if (len > MAX_COMMAND_SIZE) { + dev_err(&chip->dev, + "%s:len=%zd exceeds MAX_COMMAND_SIZE supported by fTPM TA\n", + __func__, len); + return -EIO; + } + + memset(&transceive_args, 0, sizeof(transceive_args)); + memset(command_params, 0, sizeof(command_params)); + pvt_data->resp_len = 0; + + /* Invoke FTPM_OPTEE_TA_SUBMIT_COMMAND function of fTPM TA */ + transceive_args = (struct tee_ioctl_invoke_arg) { + .func = FTPM_OPTEE_TA_SUBMIT_COMMAND, + .session = pvt_data->session, + .num_params = 4, + }; + + /* Fill FTPM_OPTEE_TA_SUBMIT_COMMAND parameters */ + command_params[0] = (struct tee_param) { + .attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT, + .u.memref = { + .shm = shm, + .size = len, + .shm_offs = 0, + }, + }; + + temp_buf = tee_shm_get_va(shm, 0); + if (IS_ERR(temp_buf)) { + dev_err(&chip->dev, "%s:tee_shm_get_va failed for transmit\n", + __func__); + return PTR_ERR(temp_buf); + } + memset(temp_buf, 0, (MAX_COMMAND_SIZE + MAX_RESPONSE_SIZE)); + + memcpy(temp_buf, buf, len); + + command_params[1] = (struct tee_param) { + .attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT, + .u.memref = { + .shm = shm, + .size = MAX_RESPONSE_SIZE, + .shm_offs = MAX_COMMAND_SIZE, + }, + }; + + rc = tee_client_invoke_func(pvt_data->ctx, &transceive_args, + command_params); + if ((rc < 0) || (transceive_args.ret != 0)) { + dev_err(&chip->dev, "%s:SUBMIT_COMMAND invoke error: 0x%x\n", + __func__, transceive_args.ret); + return (rc < 0) ? rc : transceive_args.ret; + } + + temp_buf = tee_shm_get_va(shm, command_params[1].u.memref.shm_offs); + if (IS_ERR(temp_buf)) { + dev_err(&chip->dev, "%s:tee_shm_get_va failed for receive\n", + __func__); + return PTR_ERR(temp_buf); + } + + resp_header = (struct tpm_header *)temp_buf; + resp_len = be32_to_cpu(resp_header->length); + + /* sanity check resp_len */ + if (resp_len < TPM_HEADER_SIZE) { + dev_err(&chip->dev, "%s:tpm response header too small\n", + __func__); + return -EIO; + } + if (resp_len > MAX_RESPONSE_SIZE) { + dev_err(&chip->dev, + "%s:resp_len=%zd exceeds MAX_RESPONSE_SIZE\n", + __func__, resp_len); + return -EIO; + } + + /* sanity checks look good, cache the response */ + memcpy(pvt_data->resp_buf, temp_buf, resp_len); + pvt_data->resp_len = resp_len; + + return 0; +} + +static void ftpm_tee_tpm_op_cancel(struct tpm_chip *chip) +{ + /* not supported */ +} + +static u8 ftpm_tee_tpm_op_status(struct tpm_chip *chip) +{ + return 0; +} + +static bool ftpm_tee_tpm_req_canceled(struct tpm_chip *chip, u8 status) +{ + return 0; +} + +static const struct tpm_class_ops ftpm_tee_tpm_ops = { + .flags = TPM_OPS_AUTO_STARTUP, + .recv = ftpm_tee_tpm_op_recv, + .send = ftpm_tee_tpm_op_send, + .cancel = ftpm_tee_tpm_op_cancel, + .status = ftpm_tee_tpm_op_status, + .req_complete_mask = 0, + .req_complete_val = 0, + .req_canceled = ftpm_tee_tpm_req_canceled, +}; + +/* + * Check whether this driver supports the fTPM TA in the TEE instance + * represented by the params (ver/data) to this function. + */ +static int ftpm_tee_match(struct tee_ioctl_version_data *ver, const void *data) +{ + /* + * Currently this driver only support GP Complaint OPTEE based fTPM TA + */ + if ((ver->impl_id == TEE_IMPL_ID_OPTEE) && + (ver->gen_caps & TEE_GEN_CAP_GP)) + return 1; + else + return 0; +} + +/* + * Undo what has been done in ftpm_tee_probe + */ +static void ftpm_tee_deinit(struct ftpm_tee_private *pvt_data) +{ + /* Release the chip */ + tpm_chip_unregister(pvt_data->chip); + + /* frees chip */ + if (pvt_data->chip) + put_device(&pvt_data->chip->dev); + + if (pvt_data->ctx) { + /* Free the shared memory pool */ + tee_shm_free(pvt_data->shm); + + /* close the existing session with fTPM TA*/ + tee_client_close_session(pvt_data->ctx, pvt_data->session); + + /* close the context with TEE driver */ + tee_client_close_context(pvt_data->ctx); + } + + /* memory allocated with devm_kzalloc() is freed automatically */ +} + +/** + * ftpm_tee_probe - initialize the fTPM + * @pdev: the platform_device description. + * + * Return: + * On success, 0. On failure, -errno. + */ +static int ftpm_tee_probe(struct platform_device *pdev) +{ + int rc; + struct tpm_chip *chip; + struct device *dev = &pdev->dev; + struct ftpm_tee_private *pvt_data = NULL; + struct tee_ioctl_open_session_arg sess_arg; + + pvt_data = devm_kzalloc(dev, sizeof(struct ftpm_tee_private), + GFP_KERNEL); + if (!pvt_data) + return -ENOMEM; + + dev_set_drvdata(dev, pvt_data); + + /* Open context with TEE driver */ + pvt_data->ctx = tee_client_open_context(NULL, ftpm_tee_match, NULL, + NULL); + if (IS_ERR(pvt_data->ctx)) { + dev_err(dev, "%s:tee_client_open_context failed\n", __func__); + return -EPROBE_DEFER; + } + + /* Open a session with fTPM TA */ + memset(&sess_arg, 0, sizeof(sess_arg)); + memcpy(sess_arg.uuid, ftpm_ta_uuid.b, TEE_IOCTL_UUID_LEN); + sess_arg.clnt_login = TEE_IOCTL_LOGIN_PUBLIC; + sess_arg.num_params = 0; + + rc = tee_client_open_session(pvt_data->ctx, &sess_arg, NULL); + if ((rc < 0) || (sess_arg.ret != 0)) { + dev_err(dev, "%s:tee_client_open_session failed, err=%x\n", + __func__, sess_arg.ret); + rc = -EINVAL; + goto out_tee_session; + } + pvt_data->session = sess_arg.session; + + /* Allocate dynamic shared memory with fTPM TA */ + pvt_data->shm = tee_shm_alloc(pvt_data->ctx, + (MAX_COMMAND_SIZE + MAX_RESPONSE_SIZE), + TEE_SHM_MAPPED | TEE_SHM_DMA_BUF); + if (IS_ERR(pvt_data->shm)) { + dev_err(dev, "%s:tee_shm_alloc failed\n", __func__); + rc = -ENOMEM; + goto out_shm_alloc; + } + + /* Allocate new struct tpm_chip instance */ + chip = tpm_chip_alloc(dev, &ftpm_tee_tpm_ops); + if (IS_ERR(chip)) { + dev_err(dev, "%s:tpm_chip_alloc failed\n", __func__); + rc = PTR_ERR(chip); + goto out_chip_alloc; + } + + pvt_data->chip = chip; + pvt_data->chip->flags |= TPM_CHIP_FLAG_TPM2; + + /* Create a character device for the fTPM */ + rc = tpm_chip_register(pvt_data->chip); + if (rc) { + dev_err(dev, "%s:tpm_chip_register failed with rc=%d\n", + __func__, rc); + goto out_chip; + } + + return 0; + +out_chip: + put_device(&pvt_data->chip->dev); +out_chip_alloc: + tee_shm_free(pvt_data->shm); +out_shm_alloc: + tee_client_close_session(pvt_data->ctx, pvt_data->session); +out_tee_session: + tee_client_close_context(pvt_data->ctx); + + return rc; +} + +/** + * ftpm_tee_remove - remove the TPM device + * @pdev: the platform_device description. + * + * Return: + * 0 in case of success. + */ +static int ftpm_tee_remove(struct platform_device *pdev) +{ + struct ftpm_tee_private *pvt_data = dev_get_drvdata(&pdev->dev); + + /* Release the chip */ + tpm_chip_unregister(pvt_data->chip); + + /* frees chip */ + put_device(&pvt_data->chip->dev); + + /* Free the shared memory pool */ + tee_shm_free(pvt_data->shm); + + /* close the existing session with fTPM TA*/ + tee_client_close_session(pvt_data->ctx, pvt_data->session); + + /* close the context with TEE driver */ + tee_client_close_context(pvt_data->ctx); + + /* memory allocated with devm_kzalloc() is freed automatically */ + + return 0; +} + +static const struct of_device_id of_ftpm_tee_ids[] = { + { .compatible = "microsoft,ftpm" }, + { } +}; +MODULE_DEVICE_TABLE(of, of_ftpm_tee_ids); + +static struct platform_driver ftpm_tee_driver = { + .driver = { + .name = DRIVER_NAME, + .of_match_table = of_match_ptr(of_ftpm_tee_ids), + }, + .probe = ftpm_tee_probe, + .remove = ftpm_tee_remove, +}; + +module_platform_driver(ftpm_tee_driver); + +MODULE_AUTHOR("Thirupathaiah Annapureddy <thiruan@microsoft.com>"); +MODULE_DESCRIPTION("TPM Driver for fTPM TA in TEE"); +MODULE_LICENSE("GPL v2"); diff --git a/drivers/char/tpm/tpm_ftpm_tee.h b/drivers/char/tpm/tpm_ftpm_tee.h new file mode 100644 index 0000000000000..b09ee7be45459 --- /dev/null +++ b/drivers/char/tpm/tpm_ftpm_tee.h @@ -0,0 +1,40 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) Microsoft Corporation + */ + +#ifndef __TPM_FTPM_TEE_H__ +#define __TPM_FTPM_TEE_H__ + +#include <linux/tee_drv.h> +#include <linux/tpm.h> +#include <linux/uuid.h> + +/* The TAFs ID implemented in this TA */ +#define FTPM_OPTEE_TA_SUBMIT_COMMAND (0) +#define FTPM_OPTEE_TA_EMULATE_PPI (1) + +/* max. buffer size supported by fTPM */ +#define MAX_COMMAND_SIZE 4096 +#define MAX_RESPONSE_SIZE 4096 + +/** + * struct ftpm_tee_private - fTPM's private data + * @chip: struct tpm_chip instance registered with tpm framework. + * @state: internal state + * @session: fTPM TA session identifier. + * @resp_len: cached response buffer length. + * @resp_buf: cached response buffer. + * @ctx: TEE context handler. + * @shm: Memory pool shared with fTPM TA in TEE. + */ +struct ftpm_tee_private { + struct tpm_chip *chip; + u32 session; + size_t resp_len; + u8 resp_buf[MAX_RESPONSE_SIZE]; + struct tee_context *ctx; + struct tee_shm *shm; +}; + +#endif /* __TPM_FTPM_TEE_H__ */