tpm_emulator: Avoid double initialization during migration

When resuming after a migration, the backend sends CMD_INIT to the
emulator from the startup callback, then it sends the migration state
from the vmstate to the emulator, then it sends CMD_INIT again. Skip the
first CMD_INIT during a migration to avoid initializing the TPM twice.

Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Tested-by: Stefan Berger <stefanb@linux.ibm.com>
Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>

1 files changed, 10 insertions, 0 deletions

diff --git a/backends/tpm/tpm_emulator.c b/backends/tpm/tpm_emulator.c
index 87d061e9bb..9b50c5b3e2 100644
--- a/backends/tpm/tpm_emulator.c
+++ b/backends/tpm/tpm_emulator.c
@@ -32,6 +32,7 @@
 #include "qemu/sockets.h"
 #include "qemu/lockable.h"
 #include "io/channel-socket.h"
+#include "sysemu/runstate.h"
 #include "sysemu/tpm_backend.h"
 #include "sysemu/tpm_util.h"
 #include "tpm_int.h"
@@ -383,6 +384,15 @@ err_exit:
 
 static int tpm_emulator_startup_tpm(TPMBackend *tb, size_t buffersize)
 {
+    /* TPM startup will be done from post_load hook */
+    if (runstate_check(RUN_STATE_INMIGRATE)) {
+        if (buffersize != 0) {
+            return tpm_emulator_set_buffer_size(tb, buffersize, NULL);
+        }
+
+        return 0;
+    }
+
     return tpm_emulator_startup_tpm_resume(tb, buffersize, false);
 }