diff options
author | Stefan Berger <stefanb@linux.vnet.ibm.com> | 2015-05-26 16:51:06 -0400 |
---|---|---|
committer | Michael S. Tsirkin <mst@redhat.com> | 2015-05-31 20:29:02 +0200 |
commit | 56a3c24ffc11955ddc7bb21362ca8069a3fc8c55 (patch) | |
tree | baca140a842afc89c79ba1724f28877b3737a0ce | |
parent | 116694c34aa794a994051fce55bfee418fe1521d (diff) | |
download | qemu-56a3c24ffc11955ddc7bb21362ca8069a3fc8c55.zip qemu-56a3c24ffc11955ddc7bb21362ca8069a3fc8c55.tar.gz qemu-56a3c24ffc11955ddc7bb21362ca8069a3fc8c55.tar.bz2 |
tpm: Probe for connected TPM 1.2 or TPM 2
In the TPM passthrough backend driver, modify the probing code so
that we can check whether a TPM 1.2 or TPM 2 is being used
and adapt the behavior of the TPM TIS accordingly.
Move the code that tested for a TPM 1.2 into tpm_utils.c
and extend it with test for probing for TPM 2. Have the
function return the version of TPM found.
Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
-rw-r--r-- | hw/tpm/Makefile.objs | 2 | ||||
-rw-r--r-- | hw/tpm/tpm_int.h | 6 | ||||
-rw-r--r-- | hw/tpm/tpm_passthrough.c | 59 | ||||
-rw-r--r-- | hw/tpm/tpm_util.c | 126 | ||||
-rw-r--r-- | hw/tpm/tpm_util.h | 28 |
5 files changed, 167 insertions, 54 deletions
diff --git a/hw/tpm/Makefile.objs b/hw/tpm/Makefile.objs index 99f5983..64cecc3 100644 --- a/hw/tpm/Makefile.objs +++ b/hw/tpm/Makefile.objs @@ -1,2 +1,2 @@ common-obj-$(CONFIG_TPM_TIS) += tpm_tis.o -common-obj-$(CONFIG_TPM_PASSTHROUGH) += tpm_passthrough.o +common-obj-$(CONFIG_TPM_PASSTHROUGH) += tpm_passthrough.o tpm_util.o diff --git a/hw/tpm/tpm_int.h b/hw/tpm/tpm_int.h index 9866c79..f2f285b 100644 --- a/hw/tpm/tpm_int.h +++ b/hw/tpm/tpm_int.h @@ -66,4 +66,10 @@ struct tpm_resp_hdr { #define TPM_ORD_ContinueSelfTest 0x53 #define TPM_ORD_GetTicks 0xf1 + +/* TPM2 defines */ +#define TPM2_ST_NO_SESSIONS 0x8001 + +#define TPM2_CC_ReadClock 0x00000181 + #endif /* TPM_TPM_INT_H */ diff --git a/hw/tpm/tpm_passthrough.c b/hw/tpm/tpm_passthrough.c index f1361d2..8d8523a 100644 --- a/hw/tpm/tpm_passthrough.c +++ b/hw/tpm/tpm_passthrough.c @@ -33,6 +33,7 @@ #include "hw/i386/pc.h" #include "sysemu/tpm_backend_int.h" #include "tpm_tis.h" +#include "tpm_util.h" #define DEBUG_TPM 0 @@ -69,6 +70,8 @@ struct TPMPassthruState { bool tpm_op_canceled; int cancel_fd; bool had_startup_error; + + TPMVersion tpm_version; }; typedef struct TPMPassthruState TPMPassthruState; @@ -333,59 +336,9 @@ static const char *tpm_passthrough_create_desc(void) static TPMVersion tpm_passthrough_get_tpm_version(TPMBackend *tb) { - return TPM_VERSION_1_2; -} - -/* - * A basic test of a TPM device. We expect a well formatted response header - * (error response is fine) within one second. - */ -static int tpm_passthrough_test_tpmdev(int fd) -{ - struct tpm_req_hdr req = { - .tag = cpu_to_be16(TPM_TAG_RQU_COMMAND), - .len = cpu_to_be32(sizeof(req)), - .ordinal = cpu_to_be32(TPM_ORD_GetTicks), - }; - struct tpm_resp_hdr *resp; - fd_set readfds; - int n; - struct timeval tv = { - .tv_sec = 1, - .tv_usec = 0, - }; - unsigned char buf[1024]; - - n = write(fd, &req, sizeof(req)); - if (n < 0) { - return errno; - } - if (n != sizeof(req)) { - return EFAULT; - } - - FD_ZERO(&readfds); - FD_SET(fd, &readfds); - - /* wait for a second */ - n = select(fd + 1, &readfds, NULL, NULL, &tv); - if (n != 1) { - return errno; - } - - n = read(fd, &buf, sizeof(buf)); - if (n < sizeof(struct tpm_resp_hdr)) { - return EFAULT; - } - - resp = (struct tpm_resp_hdr *)buf; - /* check the header */ - if (be16_to_cpu(resp->tag) != TPM_TAG_RSP_COMMAND || - be32_to_cpu(resp->len) != n) { - return EBADMSG; - } + TPMPassthruState *tpm_pt = TPM_PASSTHROUGH(tb); - return 0; + return tpm_pt->tpm_version; } /* @@ -455,7 +408,7 @@ static int tpm_passthrough_handle_device_opts(QemuOpts *opts, TPMBackend *tb) goto err_free_parameters; } - if (tpm_passthrough_test_tpmdev(tpm_pt->tpm_fd)) { + if (tpm_util_test_tpmdev(tpm_pt->tpm_fd, &tpm_pt->tpm_version)) { error_report("'%s' is not a TPM device.", tpm_pt->tpm_dev); goto err_close_tpmdev; diff --git a/hw/tpm/tpm_util.c b/hw/tpm/tpm_util.c new file mode 100644 index 0000000..4ace585 --- /dev/null +++ b/hw/tpm/tpm_util.c @@ -0,0 +1,126 @@ +/* + * TPM utility functions + * + * Copyright (c) 2010 - 2015 IBM Corporation + * Authors: + * Stefan Berger <stefanb@us.ibm.com> + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, see <http://www.gnu.org/licenses/> + */ + +#include "tpm_util.h" +#include "tpm_int.h" + +/* + * A basic test of a TPM device. We expect a well formatted response header + * (error response is fine) within one second. + */ +static int tpm_util_test(int fd, + unsigned char *request, + size_t requestlen, + uint16_t *return_tag) +{ + struct tpm_resp_hdr *resp; + fd_set readfds; + int n; + struct timeval tv = { + .tv_sec = 1, + .tv_usec = 0, + }; + unsigned char buf[1024]; + + n = write(fd, request, requestlen); + if (n < 0) { + return errno; + } + if (n != requestlen) { + return EFAULT; + } + + FD_ZERO(&readfds); + FD_SET(fd, &readfds); + + /* wait for a second */ + n = select(fd + 1, &readfds, NULL, NULL, &tv); + if (n != 1) { + return errno; + } + + n = read(fd, &buf, sizeof(buf)); + if (n < sizeof(struct tpm_resp_hdr)) { + return EFAULT; + } + + resp = (struct tpm_resp_hdr *)buf; + /* check the header */ + if (be32_to_cpu(resp->len) != n) { + return EBADMSG; + } + + *return_tag = be16_to_cpu(resp->tag); + + return 0; +} + +/* + * Probe for the TPM device in the back + * Returns 0 on success with the version of the probed TPM set, 1 on failure. + */ +int tpm_util_test_tpmdev(int tpm_fd, TPMVersion *tpm_version) +{ + /* + * Sending a TPM1.2 command to a TPM2 should return a TPM1.2 + * header (tag = 0xc4) and error code (TPM_BADTAG = 0x1e) + * + * Sending a TPM2 command to a TPM 2 will give a TPM 2 tag in the + * header. + * Sending a TPM2 command to a TPM 1.2 will give a TPM 1.2 tag + * in the header and an error code. + */ + const struct tpm_req_hdr test_req = { + .tag = cpu_to_be16(TPM_TAG_RQU_COMMAND), + .len = cpu_to_be32(sizeof(test_req)), + .ordinal = cpu_to_be32(TPM_ORD_GetTicks), + }; + + const struct tpm_req_hdr test_req_tpm2 = { + .tag = cpu_to_be16(TPM2_ST_NO_SESSIONS), + .len = cpu_to_be32(sizeof(test_req_tpm2)), + .ordinal = cpu_to_be32(TPM2_CC_ReadClock), + }; + uint16_t return_tag; + int ret; + + /* Send TPM 2 command */ + ret = tpm_util_test(tpm_fd, (unsigned char *)&test_req_tpm2, + sizeof(test_req_tpm2), &return_tag); + /* TPM 2 would respond with a tag of TPM2_ST_NO_SESSIONS */ + if (!ret && return_tag == TPM2_ST_NO_SESSIONS) { + *tpm_version = TPM_VERSION_2_0; + return 0; + } + + /* Send TPM 1.2 command */ + ret = tpm_util_test(tpm_fd, (unsigned char *)&test_req, + sizeof(test_req), &return_tag); + if (!ret && return_tag == TPM_TAG_RSP_COMMAND) { + *tpm_version = TPM_VERSION_1_2; + /* this is a TPM 1.2 */ + return 0; + } + + *tpm_version = TPM_VERSION_UNSPEC; + + return 1; +} diff --git a/hw/tpm/tpm_util.h b/hw/tpm/tpm_util.h new file mode 100644 index 0000000..e7f354a --- /dev/null +++ b/hw/tpm/tpm_util.h @@ -0,0 +1,28 @@ +/* + * TPM utility functions + * + * Copyright (c) 2010 - 2015 IBM Corporation + * Authors: + * Stefan Berger <stefanb@us.ibm.com> + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, see <http://www.gnu.org/licenses/> + */ +#ifndef TPM_TPM_UTILS_H +#define TPM_TPM_UTILS_H + +#include "sysemu/tpm_backend.h" + +int tpm_util_test_tpmdev(int tpm_fd, TPMVersion *tpm_version); + +#endif /* TPM_TPM_UTILS_H */ |