From abc5cda097f46bdb86833a38ee0961a0e6a47ae1 Mon Sep 17 00:00:00 2001 From: Stefan Berger Date: Fri, 3 Nov 2017 22:49:23 -0400 Subject: [PATCH] tpm: tpm_passthrough: Read the buffer size from the host device MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Rather than hard coding the buffer size in the tpm_passthrough backend read the TPM I/O buffer size from the host device. Signed-off-by: Stefan Berger Reviewed-by: Marc-André Lureau --- hw/tpm/tpm_int.h | 9 +++ hw/tpm/tpm_passthrough.c | 11 +++- hw/tpm/tpm_util.c | 115 +++++++++++++++++++++++++++++++++++++++ hw/tpm/tpm_util.h | 3 + 4 files changed, 137 insertions(+), 1 deletion(-) diff --git a/hw/tpm/tpm_int.h b/hw/tpm/tpm_int.h index 1df5883f3c..abbca5191a 100644 --- a/hw/tpm/tpm_int.h +++ b/hw/tpm/tpm_int.h @@ -45,11 +45,20 @@ struct tpm_resp_hdr { #define TPM_ORD_ContinueSelfTest 0x53 #define TPM_ORD_GetTicks 0xf1 +#define TPM_ORD_GetCapability 0x65 +#define TPM_CAP_PROPERTY 0x05 + +#define TPM_CAP_PROP_INPUT_BUFFER 0x124 /* TPM2 defines */ #define TPM2_ST_NO_SESSIONS 0x8001 #define TPM2_CC_ReadClock 0x00000181 +#define TPM2_CC_GetCapability 0x0000017a + +#define TPM2_CAP_TPM_PROPERTIES 0x6 + +#define TPM2_PT_MAX_COMMAND_SIZE 0x11e #endif /* TPM_TPM_INT_H */ diff --git a/hw/tpm/tpm_passthrough.c b/hw/tpm/tpm_passthrough.c index daac67d44a..886af9e702 100644 --- a/hw/tpm/tpm_passthrough.c +++ b/hw/tpm/tpm_passthrough.c @@ -57,6 +57,7 @@ struct TPMPassthruState { int cancel_fd; TPMVersion tpm_version; + size_t tpm_buffersize; }; typedef struct TPMPassthruState TPMPassthruState; @@ -201,7 +202,15 @@ static TPMVersion tpm_passthrough_get_tpm_version(TPMBackend *tb) static size_t tpm_passthrough_get_buffer_size(TPMBackend *tb) { - return 4096; + TPMPassthruState *tpm_pt = TPM_PASSTHROUGH(tb); + int ret; + + ret = tpm_util_get_buffer_size(tpm_pt->tpm_fd, tpm_pt->tpm_version, + &tpm_pt->tpm_buffersize); + if (ret < 0) { + tpm_pt->tpm_buffersize = 4096; + } + return tpm_pt->tpm_buffersize; } /* diff --git a/hw/tpm/tpm_util.c b/hw/tpm/tpm_util.c index b852f53b8d..a317243a7e 100644 --- a/hw/tpm/tpm_util.c +++ b/hw/tpm/tpm_util.c @@ -20,10 +20,19 @@ */ #include "qemu/osdep.h" +#include "qemu/error-report.h" #include "tpm_util.h" #include "tpm_int.h" #include "exec/memory.h" +#define DEBUG_TPM 0 + +#define DPRINTF(fmt, ...) do { \ + if (DEBUG_TPM) { \ + fprintf(stderr, "tpm-util:"fmt"\n", ## __VA_ARGS__); \ + } \ +} while (0) + /* * Write an error message in the given output buffer. */ @@ -173,3 +182,109 @@ int tpm_util_test_tpmdev(int tpm_fd, TPMVersion *tpm_version) return 1; } + +int tpm_util_get_buffer_size(int tpm_fd, TPMVersion tpm_version, + size_t *buffersize) +{ + unsigned char buf[1024]; + int ret; + + switch (tpm_version) { + case TPM_VERSION_1_2: { + const struct tpm_req_get_buffer_size { + struct tpm_req_hdr hdr; + uint32_t capability; + uint32_t len; + uint32_t subcap; + } QEMU_PACKED tpm_get_buffer_size = { + .hdr = { + .tag = cpu_to_be16(TPM_TAG_RQU_COMMAND), + .len = cpu_to_be32(sizeof(tpm_get_buffer_size)), + .ordinal = cpu_to_be32(TPM_ORD_GetCapability), + }, + .capability = cpu_to_be32(TPM_CAP_PROPERTY), + .len = cpu_to_be32(sizeof(uint32_t)), + .subcap = cpu_to_be32(TPM_CAP_PROP_INPUT_BUFFER), + }; + struct tpm_resp_get_buffer_size { + struct tpm_resp_hdr hdr; + uint32_t len; + uint32_t buffersize; + } QEMU_PACKED *tpm_resp = (struct tpm_resp_get_buffer_size *)buf; + + ret = tpm_util_request(tpm_fd, (unsigned char *)&tpm_get_buffer_size, + sizeof(tpm_get_buffer_size), buf, sizeof(buf)); + if (ret < 0) { + return ret; + } + + if (be32_to_cpu(tpm_resp->hdr.len) != sizeof(*tpm_resp) || + be32_to_cpu(tpm_resp->len) != sizeof(uint32_t)) { + DPRINTF("tpm_resp->hdr.len = %u, expected = %zu\n", + be32_to_cpu(tpm_resp->hdr.len), sizeof(*tpm_resp)); + DPRINTF("tpm_resp->len = %u, expected = %zu\n", + be32_to_cpu(tpm_resp->len), sizeof(uint32_t)); + error_report("tpm_util: Got unexpected response to " + "TPM_GetCapability; errcode: 0x%x", + be32_to_cpu(tpm_resp->hdr.errcode)); + return -EFAULT; + } + *buffersize = be32_to_cpu(tpm_resp->buffersize); + break; + } + case TPM_VERSION_2_0: { + const struct tpm2_req_get_buffer_size { + struct tpm_req_hdr hdr; + uint32_t capability; + uint32_t property; + uint32_t count; + } QEMU_PACKED tpm2_get_buffer_size = { + .hdr = { + .tag = cpu_to_be16(TPM2_ST_NO_SESSIONS), + .len = cpu_to_be32(sizeof(tpm2_get_buffer_size)), + .ordinal = cpu_to_be32(TPM2_CC_GetCapability), + }, + .capability = cpu_to_be32(TPM2_CAP_TPM_PROPERTIES), + .property = cpu_to_be32(TPM2_PT_MAX_COMMAND_SIZE), + .count = cpu_to_be32(2), /* also get TPM2_PT_MAX_RESPONSE_SIZE */ + }; + struct tpm2_resp_get_buffer_size { + struct tpm_resp_hdr hdr; + uint8_t more; + uint32_t capability; + uint32_t count; + uint32_t property1; + uint32_t value1; + uint32_t property2; + uint32_t value2; + } QEMU_PACKED *tpm2_resp = (struct tpm2_resp_get_buffer_size *)buf; + + ret = tpm_util_request(tpm_fd, (unsigned char *)&tpm2_get_buffer_size, + sizeof(tpm2_get_buffer_size), buf, sizeof(buf)); + if (ret < 0) { + return ret; + } + + if (be32_to_cpu(tpm2_resp->hdr.len) != sizeof(*tpm2_resp) || + be32_to_cpu(tpm2_resp->count) != 2) { + DPRINTF("tpm2_resp->hdr.len = %u, expected = %zu\n", + be32_to_cpu(tpm2_resp->hdr.len), sizeof(*tpm2_resp)); + DPRINTF("tpm2_resp->len = %u, expected = %u\n", + be32_to_cpu(tpm2_resp->count), 2); + error_report("tpm_util: Got unexpected response to " + "TPM2_GetCapability; errcode: 0x%x", + be32_to_cpu(tpm2_resp->hdr.errcode)); + return -EFAULT; + } + *buffersize = MAX(be32_to_cpu(tpm2_resp->value1), + be32_to_cpu(tpm2_resp->value2)); + break; + } + case TPM_VERSION_UNSPEC: + return -EFAULT; + } + + DPRINTF("buffersize of device: %zu\n", *buffersize); + + return 0; +} diff --git a/hw/tpm/tpm_util.h b/hw/tpm/tpm_util.h index aca10c97bf..1c17e3913b 100644 --- a/hw/tpm/tpm_util.h +++ b/hw/tpm/tpm_util.h @@ -36,4 +36,7 @@ static inline uint32_t tpm_cmd_get_size(const void *b) return be32_to_cpu(*(const uint32_t *)(b + 2)); } +int tpm_util_get_buffer_size(int tpm_fd, TPMVersion tpm_version, + size_t *buffersize); + #endif /* TPM_TPM_UTIL_H */