Using swtpm v0.7.0 we can run swtpm_setup to create default config files
for swtpm_setup and swtpm-localca in session mode. Now a user can start
a VM with an attached TPM without having to run this program on the
command line before. This program needs to run once.

This patch addresses the issue raised in
https://bugzilla.redhat.com/show_bug.cgi?id=2010649

Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>

v2:
  - fixed return code if swtpm_setup doesn't support the option
---
 src/qemu/qemu_tpm.c | 43 +++++++++++++++++++++++++++++++++++++++++++
 src/util/virtpm.c   |  1 +
 src/util/virtpm.h   |  1 +
 3 files changed, 45 insertions(+)

diff --git a/src/qemu/qemu_tpm.c b/src/qemu/qemu_tpm.c
index 100481503c..bf6c8e5ad5 100644
--- a/src/qemu/qemu_tpm.c
+++ b/src/qemu/qemu_tpm.c
@@ -385,6 +385,46 @@ qemuTPMSetupEncryption(const unsigned char *secretuuid,
     return virCommandSetSendBuffer(cmd, g_steal_pointer(&secret), secret_len);
 }

+
+/*
+ * qemuTPMCreateConfigFiles: run swtpm_setup --create-config-files skip-if-exist
+ *
+ * @logfile: The file to write the log into; it must be writable
+ *           for the user given by userid or 'tss'
+ */
+static int
+qemuTPMCreateConfigFiles(const char *logfile)
+{
+    g_autofree char *swtpm_setup = virTPMGetSwtpmSetup();
+    g_autoptr(virCommand) cmd = NULL;
+    int exitstatus;
+
+    if (!swtpm_setup)
+        return -1;
+
+    if (!virTPMSwtpmSetupCapsGet(
+            VIR_TPM_SWTPM_SETUP_FEATURE_CMDARG_CREATE_CONFIG_FILES))
+        return 0;
+
+    cmd = virCommandNew(swtpm_setup);
+    if (!cmd)
+        return -1;
+
+    virCommandAddArgList(cmd, "--create-config-files", "skip-if-exist", NULL);
+    virCommandClearCaps(cmd);
+
+    if (virCommandRun(cmd, &exitstatus) < 0 || exitstatus != 0) {
+        virReportError(VIR_ERR_INTERNAL_ERROR,
+                       _("Could not run '%s' to create config files. exitstatus: %d; "
+                         "Check error log '%s' for details."),
+                          swtpm_setup, exitstatus, logfile);

+        return -1;
+    }
+
+    return 0;
+}
+
+
 /*
  * qemuTPMEmulatorRunSetup
  *
@@ -432,6 +472,9 @@ qemuTPMEmulatorRunSetup(const char *storagepath,
                                  "this requires privileged mode for a "
                                  "TPM 1.2\n"), 0600);

+    if (!privileged && qemuTPMCreateConfigFiles(logfile))
+        return -1;
+
     cmd = virCommandNew(swtpm_setup);
     if (!cmd)
         return -1;
diff --git a/src/util/virtpm.c b/src/util/virtpm.c
index 1a567139b4..0f50de866c 100644
--- a/src/util/virtpm.c
+++ b/src/util/virtpm.c
@@ -45,6 +45,7 @@ VIR_ENUM_IMPL(virTPMSwtpmFeature,
 VIR_ENUM_IMPL(virTPMSwtpmSetupFeature,
               VIR_TPM_SWTPM_SETUP_FEATURE_LAST,
               "cmdarg-pwdfile-fd",
+              "cmdarg-create-config-files",
 );

 /**
diff --git a/src/util/virtpm.h b/src/util/virtpm.h
index d021a083b4..3bb03b3b33 100644
--- a/src/util/virtpm.h
+++ b/src/util/virtpm.h
@@ -38,6 +38,7 @@ typedef enum {

 typedef enum {
     VIR_TPM_SWTPM_SETUP_FEATURE_CMDARG_PWDFILE_FD,
+    VIR_TPM_SWTPM_SETUP_FEATURE_CMDARG_CREATE_CONFIG_FILES,

     VIR_TPM_SWTPM_SETUP_FEATURE_LAST
 } virTPMSwtpmSetupFeature;
--
2.31.1