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 <address@hidden>
---
hw/tpm/tpm_int.h | 9 ++++
hw/tpm/tpm_passthrough.c | 11 ++++-
hw/tpm/tpm_util.c | 116 +++++++++++++++++++++++++++++++++++++++++++++++
hw/tpm/tpm_util.h | 3 ++
4 files changed, 138 insertions(+), 1 deletion(-)
diff --git a/hw/tpm/tpm_int.h b/hw/tpm/tpm_int.h
index 1df5883..f838535 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_INPUT_BUFFER 0x10d
#endif /* TPM_TPM_INT_H */
diff --git a/hw/tpm/tpm_passthrough.c b/hw/tpm/tpm_passthrough.c
index 7ff9249..ec755fe 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;
+ uint32_t tpm_buffersize;
};
typedef struct TPMPassthruState TPMPassthruState;
@@ -201,7 +202,15 @@ static TPMVersion
tpm_passthrough_get_tpm_version(TPMBackend *tb)
static uint32_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 396e793..3c861ab 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.
*/
@@ -170,3 +179,110 @@ 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,
+ uint32_t *buffersize)
+{
+ unsigned char buf[1024];
+ 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),
+ };
+ 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_INPUT_BUFFER),
+ .count = cpu_to_be32(1),
+ };
+ 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;
+ struct tpm2_resp_get_buffer_size {
+ struct tpm_resp_hdr hdr;
+ uint8_t more;
+ uint32_t capability;
+ uint32_t count;
+ uint32_t property;
+ uint32_t value;
+ } QEMU_PACKED *tpm2_resp = (struct tpm2_resp_get_buffer_size *)buf;
+ unsigned char *request = NULL;
+ size_t requestlen;
+ int ret;
+
+ switch (tpm_version) {
+ case TPM_VERSION_1_2:
+ request = (unsigned char *)&tpm_get_buffer_size;
+ requestlen = sizeof(tpm_get_buffer_size);
+ break;
+ case TPM_VERSION_2_0:
+ request = (unsigned char *)&tpm2_get_buffer_size;
+ requestlen = sizeof(tpm2_get_buffer_size);
+ break;
+ case TPM_VERSION_UNSPEC:
+ return -EFAULT;
+ }
+
+ ret = tpm_util_tx(tpm_fd, request, requestlen, buf, sizeof(buf));
+ if (ret < 0) {
+ return ret;
+ }
+
+ switch (tpm_version) {
+ case TPM_VERSION_1_2:
+ 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 malformed 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:
+ if (be32_to_cpu(tpm2_resp->hdr.len) != sizeof(*tpm2_resp) ||
+ be32_to_cpu(tpm2_resp->count) != 1) {
+ 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), 1);
+ error_report("tpm_util: Got malformed response to "
+ "TPM2_GetCapability; errcode: 0x%x",
+ be32_to_cpu(tpm2_resp->hdr.errcode));
+ return -EFAULT;
+ }
+ *buffersize = be32_to_cpu(tpm2_resp->value);
+ break;
+ case TPM_VERSION_UNSPEC:
+ break;
+ }
+
+ DPRINTF("buffersize of device: %u\n", *buffersize);
+
+ return 0;
+}
diff --git a/hw/tpm/tpm_util.h b/hw/tpm/tpm_util.h
index aca10c9..e4fba32 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,
+ uint32_t *buffersize);
+
#endif /* TPM_TPM_UTIL_H */