tpm-backend: Add new API to read backend TpmInfo

TPM configuration options are backend implementation details and shall not be
part of base TPMBackend object, and these shall not be accessed directly outside
of the class, hence added a new interface method, get_tpm_options() to
TPMDriverOps., which shall be implemented by the derived classes to return
configured tpm options.

A new tpm backend api - tpm_backend_query_tpm() which uses _get_tpm_options() to
prepare TpmInfo.

Signed-off-by: Amarnath Valluri <amarnath.valluri@intel.com>
Reviewed-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>

4 files changed, 59 insertions, 54 deletions

diff --git a/backends/tpm.c b/backends/tpm.c
index 8911597fab..de313c9d5a 100644
--- a/backends/tpm.c
+++ b/backends/tpm.c
@@ -142,6 +142,19 @@ TPMVersion tpm_backend_get_tpm_version(TPMBackend *s)
     return k->ops->get_tpm_version(s);
 }
 
+TPMInfo *tpm_backend_query_tpm(TPMBackend *s)
+{
+    TPMInfo *info = g_new0(TPMInfo, 1);
+    TPMBackendClass *k = TPM_BACKEND_GET_CLASS(s);
+
+    info->id = g_strdup(s->id);
+    info->model = s->fe_model;
+    info->options = k->ops->get_tpm_options ?
+                    k->ops->get_tpm_options(s) : NULL;
+
+    return info;
+}
+
 static bool tpm_backend_prop_get_opened(Object *obj, Error **errp)
 {
     TPMBackend *s = TPM_BACKEND(obj);
@@ -196,8 +209,6 @@ static void tpm_backend_instance_finalize(Object *obj)
     TPMBackend *s = TPM_BACKEND(obj);
 
     g_free(s->id);
-    g_free(s->path);
-    g_free(s->cancel_path);
     tpm_backend_thread_end(s);
 }
 
diff --git a/hw/tpm/tpm_passthrough.c b/hw/tpm/tpm_passthrough.c
index 4c21e52b7c..84fc49a4d3 100644
--- a/hw/tpm/tpm_passthrough.c
+++ b/hw/tpm/tpm_passthrough.c
@@ -30,6 +30,7 @@
 #include "tpm_int.h"
 #include "hw/hw.h"
 #include "hw/i386/pc.h"
+#include "qapi/clone-visitor.h"
 #include "tpm_tis.h"
 #include "tpm_util.h"
 
@@ -49,7 +50,8 @@
 struct TPMPassthruState {
     TPMBackend parent;
 
-    char *tpm_dev;
+    TPMPassthroughOptions *options;
+    const char *tpm_dev;
     int tpm_fd;
     bool tpm_executing;
     bool tpm_op_canceled;
@@ -296,15 +298,14 @@ static TPMVersion tpm_passthrough_get_tpm_version(TPMBackend *tb)
  * in Documentation/ABI/stable/sysfs-class-tpm.
  * From /dev/tpm0 create /sys/class/misc/tpm0/device/cancel
  */
-static int tpm_passthrough_open_sysfs_cancel(TPMBackend *tb)
+static int tpm_passthrough_open_sysfs_cancel(TPMPassthruState *tpm_pt)
 {
-    TPMPassthruState *tpm_pt = TPM_PASSTHROUGH(tb);
     int fd = -1;
     char *dev;
     char path[PATH_MAX];
 
-    if (tb->cancel_path) {
-        fd = qemu_open(tb->cancel_path, O_WRONLY);
+    if (tpm_pt->options->cancel_path) {
+        fd = qemu_open(tpm_pt->options->cancel_path, O_WRONLY);
         if (fd < 0) {
             error_report("Could not open TPM cancel path : %s",
                          strerror(errno));
@@ -319,7 +320,7 @@ static int tpm_passthrough_open_sysfs_cancel(TPMBackend *tb)
                      dev) < sizeof(path)) {
             fd = qemu_open(path, O_WRONLY);
             if (fd >= 0) {
-                tb->cancel_path = g_strdup(path);
+                tpm_pt->options->cancel_path = g_strdup(path);
             } else {
                 error_report("tpm_passthrough: Could not open TPM cancel "
                              "path %s : %s", path, strerror(errno));
@@ -339,17 +340,18 @@ static int tpm_passthrough_handle_device_opts(QemuOpts *opts, TPMBackend *tb)
     const char *value;
 
     value = qemu_opt_get(opts, "cancel-path");
-    tb->cancel_path = g_strdup(value);
+    if (value) {
+        tpm_pt->options->cancel_path = g_strdup(value);
+        tpm_pt->options->has_cancel_path = true;
+    }
 
     value = qemu_opt_get(opts, "path");
-    if (!value) {
-        value = TPM_PASSTHROUGH_DEFAULT_DEVICE;
+    if (value) {
+        tpm_pt->options->has_path = true;
+        tpm_pt->options->path = g_strdup(value);
     }
 
-    tpm_pt->tpm_dev = g_strdup(value);
-
-    tb->path = g_strdup(tpm_pt->tpm_dev);
-
+    tpm_pt->tpm_dev = value ? value : TPM_PASSTHROUGH_DEFAULT_DEVICE;
     tpm_pt->tpm_fd = qemu_open(tpm_pt->tpm_dev, O_RDWR);
     if (tpm_pt->tpm_fd < 0) {
         error_report("Cannot access TPM device using '%s': %s",
@@ -370,10 +372,8 @@ static int tpm_passthrough_handle_device_opts(QemuOpts *opts, TPMBackend *tb)
     tpm_pt->tpm_fd = -1;
 
  err_free_parameters:
-    g_free(tb->path);
-    tb->path = NULL;
-
-    g_free(tpm_pt->tpm_dev);
+    qapi_free_TPMPassthroughOptions(tpm_pt->options);
+    tpm_pt->options = NULL;
     tpm_pt->tpm_dev = NULL;
 
     return 1;
@@ -391,7 +391,7 @@ static TPMBackend *tpm_passthrough_create(QemuOpts *opts, const char *id)
         goto err_exit;
     }
 
-    tpm_pt->cancel_fd = tpm_passthrough_open_sysfs_cancel(tb);
+    tpm_pt->cancel_fd = tpm_passthrough_open_sysfs_cancel(tpm_pt);
     if (tpm_pt->cancel_fd < 0) {
         goto err_exit;
     }
@@ -404,6 +404,17 @@ err_exit:
     return NULL;
 }
 
+static TpmTypeOptions *tpm_passthrough_get_tpm_options(TPMBackend *tb)
+{
+    TpmTypeOptions *options = g_new0(TpmTypeOptions, 1);
+
+    options->type = TPM_TYPE_OPTIONS_KIND_PASSTHROUGH;
+    options->u.passthrough.data = QAPI_CLONE(TPMPassthroughOptions,
+                                             TPM_PASSTHROUGH(tb)->options);
+
+    return options;
+}
+
 static const QemuOptDesc tpm_passthrough_cmdline_opts[] = {
     TPM_STANDARD_CMDLINE_OPTS,
     {
@@ -430,12 +441,14 @@ static const TPMDriverOps tpm_passthrough_driver = {
     .get_tpm_established_flag = tpm_passthrough_get_tpm_established_flag,
     .reset_tpm_established_flag = tpm_passthrough_reset_tpm_established_flag,
     .get_tpm_version          = tpm_passthrough_get_tpm_version,
+    .get_tpm_options          = tpm_passthrough_get_tpm_options,
 };
 
 static void tpm_passthrough_inst_init(Object *obj)
 {
     TPMPassthruState *tpm_pt = TPM_PASSTHROUGH(obj);
 
+    tpm_pt->options = g_new0(TPMPassthroughOptions, 1);
     tpm_pt->tpm_fd = -1;
     tpm_pt->cancel_fd = -1;
 }
@@ -448,7 +461,7 @@ static void tpm_passthrough_inst_finalize(Object *obj)
 
     qemu_close(tpm_pt->tpm_fd);
     qemu_close(tpm_pt->cancel_fd);
-    g_free(tpm_pt->tpm_dev);
+    qapi_free_TPMPassthroughOptions(tpm_pt->options);
 }
 
 static void tpm_passthrough_class_init(ObjectClass *klass, void *data)
diff --git a/include/sysemu/tpm_backend.h b/include/sysemu/tpm_backend.h
index 9ea707253a..e96c1918cc 100644
--- a/include/sysemu/tpm_backend.h
+++ b/include/sysemu/tpm_backend.h
@@ -49,10 +49,9 @@ struct TPMBackend {
     TPMRecvDataCB *recv_data_callback;
     bool had_startup_error;
 
+    /* <public> */
     char *id;
     enum TpmModel fe_model;
-    char *path;
-    char *cancel_path;
 
     QLIST_ENTRY(TPMBackend) list;
 };
@@ -96,6 +95,8 @@ struct TPMDriverOps {
     int (*reset_tpm_established_flag)(TPMBackend *t, uint8_t locty);
 
     TPMVersion (*get_tpm_version)(TPMBackend *t);
+
+    TpmTypeOptions *(*get_tpm_options)(TPMBackend *t);
 };
 
 
@@ -214,6 +215,16 @@ void tpm_backend_open(TPMBackend *s, Error **errp);
  */
 TPMVersion tpm_backend_get_tpm_version(TPMBackend *s);
 
+/**
+ * tpm_backend_query_tpm:
+ * @s: the backend
+ *
+ * Query backend tpm info
+ *
+ * Returns newly allocated TPMInfo
+ */
+TPMInfo *tpm_backend_query_tpm(TPMBackend *s);
+
 TPMBackend *qemu_find_tpm(const char *id);
 
 const TPMDriverOps *tpm_get_backend_driver(const char *type);
diff --git a/tpm.c b/tpm.c
index db14849b20..3b8c7ed3b6 100644
--- a/tpm.c
+++ b/tpm.c
@@ -202,36 +202,6 @@ static const TPMDriverOps *tpm_driver_find_by_type(enum TpmType type)
     return be_drivers[type];
 }
 
-static TPMInfo *qmp_query_tpm_inst(TPMBackend *drv)
-{
-    TPMInfo *res = g_new0(TPMInfo, 1);
-    TPMPassthroughOptions *tpo;
-
-    res->id = g_strdup(drv->id);
-    res->model = drv->fe_model;
-    res->options = g_new0(TpmTypeOptions, 1);
-
-    switch (tpm_backend_get_type(drv)) {
-    case TPM_TYPE_PASSTHROUGH:
-        res->options->type = TPM_TYPE_OPTIONS_KIND_PASSTHROUGH;
-        tpo = g_new0(TPMPassthroughOptions, 1);
-        res->options->u.passthrough.data = tpo;
-        if (drv->path) {
-            tpo->path = g_strdup(drv->path);
-            tpo->has_path = true;
-        }
-        if (drv->cancel_path) {
-            tpo->cancel_path = g_strdup(drv->cancel_path);
-            tpo->has_cancel_path = true;
-        }
-        break;
-    case TPM_TYPE__MAX:
-        break;
-    }
-
-    return res;
-}
-
 /*
  * Walk the list of active TPM backends and collect information about them
  * following the schema description in qapi-schema.json.
@@ -246,7 +216,7 @@ TPMInfoList *qmp_query_tpm(Error **errp)
             continue;
         }
         info = g_new0(TPMInfoList, 1);
-        info->value = qmp_query_tpm_inst(drv);
+        info->value = tpm_backend_query_tpm(drv);
 
         if (!cur_item) {
             head = cur_item = info;