[1/2] backends/tpm: Record the last command sent to the TPM

Commit Message

Stefan Berger May 27, 2022, 5:30 p.m. UTC

Record the last command sent to the TPM. Knowing the last command sent
to a TPM 2 will allow us to determine whether we need to send a
TPM2_Shutdown() command when the VM is reset.

Signed-off-by: Stefan Berger <[e-mail]>
---
 backends/tpm/tpm_emulator.c | 9 +++++++++
 backends/tpm/tpm_util.c     | 9 +++++++++
 include/sysemu/tpm_util.h   | 3 +++
 3 files changed, 21 insertions(+)

Patch

diff --git a/backends/tpm/tpm_emulator.c b/backends/tpm/tpm_emulator.c
index 87d061e9bb..89ecb04a2a 100644
--- a/backends/tpm/tpm_emulator.c
+++ b/backends/tpm/tpm_emulator.c
@@ -81,6 +81,8 @@  struct TPMEmulator {
     unsigned int established_flag_cached:1;
 
     TPMBlobBuffers state_blobs;
+
+    uint32_t last_command; /* last command sent to TPM */
 };
 
 struct tpm_error {
@@ -155,6 +157,12 @@  static int tpm_emulator_unix_tx_bufs(TPMEmulator *tpm_emu,
 {
     ssize_t ret;
     bool is_selftest = false;
+    uint32_t command;
+
+    command = tpm_util_get_ordinal(in, in_len);
+    if (command != TPM_ORDINAL_NONE) {
+        tpm_emu->last_command = command;
+    }
 
     if (selftest_done) {
         *selftest_done = false;
@@ -910,6 +918,7 @@  static void tpm_emulator_inst_init(Object *obj)
 
     tpm_emu->options = g_new0(TPMEmulatorOptions, 1);
     tpm_emu->cur_locty_number = ~0;
+    tpm_emu->last_command = TPM_ORDINAL_NONE;
     qemu_mutex_init(&tpm_emu->mutex);
 
     vmstate_register(NULL, VMSTATE_INSTANCE_ID_ANY,
diff --git a/backends/tpm/tpm_util.c b/backends/tpm/tpm_util.c
index a6e6d3e72f..28284940f0 100644
--- a/backends/tpm/tpm_util.c
+++ b/backends/tpm/tpm_util.c
@@ -103,6 +103,15 @@  bool tpm_util_is_selftest(const uint8_t *in, uint32_t in_len)
     return false;
 }
 
+uint32_t tpm_util_get_ordinal(const uint8_t *in, uint32_t in_len)
+{
+    if (in_len >= sizeof(struct tpm_req_hdr)) {
+        return tpm_cmd_get_ordinal(in);
+    }
+
+    return TPM_ORDINAL_NONE;
+}
+
 /*
  * Send request to a TPM device. We expect a response within one second.
  */
diff --git a/include/sysemu/tpm_util.h b/include/sysemu/tpm_util.h
index 08f05172a7..7fc238b2a0 100644
--- a/include/sysemu/tpm_util.h
+++ b/include/sysemu/tpm_util.h
@@ -29,6 +29,9 @@  void tpm_util_write_fatal_error_response(uint8_t *out, uint32_t out_len);
 
 bool tpm_util_is_selftest(const uint8_t *in, uint32_t in_len);
 
+uint32_t tpm_util_get_ordinal(const uint8_t *in, uint32_t in_len);
+#define TPM_ORDINAL_NONE 0x0
+
 int tpm_util_test_tpmdev(int tpm_fd, TPMVersion *tpm_version);
 
 static inline uint16_t tpm_cmd_get_tag(const void *b)