[PATCH v2 13/18] migration: Use keyval input visitor in HMP set command

[Fabiano Rosas <farosas@suse.de>]

Change the hmp_migrate_set_parameter command to use a keyval input
visitor.

Currently a string visitor is used and due to limitations of that
particular visitor's implementation it's necessary to consult the QAPI
type enum (MigrationParameter_lookup) and call each visit_type_*
function individually. Which makes using a visitor pointless.

Since there are other visitors implemented properly and generated code
to iterate the QAPI object, prefer using one of those. The keyval
input visitor is adequate because HMP provides basically one key and
one value for each migrate_set_parameter command.

To switch from string_input_visitor to keyval_input_visitor simply put
the parameter name and value into a dict and invoke
visit_type_MigrationParameters().

Note that it's not necessary to go through any of the keyval_* code
because due to the nature of HMP, there's no parsing to do (no '=', no
',', etc).

With this the migrate_set_parameters HMP commands will be
automatically updated anytime a new migration parameter is added.

One parameter, "cpr-exec-command", takes the strList type which needs
to be built manually. This moves to a "legacy" suffixed function.

Signed-off-by: Fabiano Rosas <farosas@suse.de>
---
 migration/migration-hmp-cmds.c     | 195 +++++++----------------------
 tests/qtest/migration/misc-tests.c |   2 +-
 2 files changed, 49 insertions(+), 148 deletions(-)

diff --git a/migration/migration-hmp-cmds.c b/migration/migration-hmp-cmds.c
index 5d754414c4..0d93d38b05 100644
--- a/migration/migration-hmp-cmds.c
+++ b/migration/migration-hmp-cmds.c
@@ -25,7 +25,9 @@
 #include "qapi/error.h"
 #include "qapi/qapi-commands-migration.h"
 #include "qapi/qapi-visit-migration.h"
+#include "qapi/qobject-input-visitor.h"
 #include "qobject/qdict.h"
+#include "qobject/qstring.h"
 #include "qapi/string-input-visitor.h"
 #include "qapi/string-output-visitor.h"
 #include "qemu/cutils.h"
@@ -600,154 +602,14 @@ end:
     hmp_handle_error(hmp, err);
 }
 
-void hmp_migrate_set_parameter(MonitorHMP *hmp, const QDict *qdict)
+static void hmp_migrate_set_parameter_legacy(MonitorHMP *hmp, const QDict *qdict)
 {
     const char *param = qdict_get_str(qdict, "parameter");
     const char *valuestr = qdict_get_str(qdict, "value");
-    Visitor *v = string_input_visitor_new(valuestr);
     MigrationParameters *p = g_new0(MigrationParameters, 1);
-    uint64_t cache_size;
     Error *err = NULL;
-    int val;
 
-    val = qapi_enum_parse(&MigrationParameter_lookup, param, -1, &err);
-    if (val < 0) {
-        goto cleanup;
-    }
-
-    switch (val) {
-    case MIGRATION_PARAMETER_THROTTLE_TRIGGER_THRESHOLD:
-        p->has_throttle_trigger_threshold = true;
-        visit_type_uint8(v, param, &p->throttle_trigger_threshold, &err);
-        break;
-    case MIGRATION_PARAMETER_CPU_THROTTLE_INITIAL:
-        p->has_cpu_throttle_initial = true;
-        visit_type_uint8(v, param, &p->cpu_throttle_initial, &err);
-        break;
-    case MIGRATION_PARAMETER_CPU_THROTTLE_INCREMENT:
-        p->has_cpu_throttle_increment = true;
-        visit_type_uint8(v, param, &p->cpu_throttle_increment, &err);
-        break;
-    case MIGRATION_PARAMETER_CPU_THROTTLE_TAILSLOW:
-        p->has_cpu_throttle_tailslow = true;
-        visit_type_bool(v, param, &p->cpu_throttle_tailslow, &err);
-        break;
-    case MIGRATION_PARAMETER_MAX_CPU_THROTTLE:
-        p->has_max_cpu_throttle = true;
-        visit_type_uint8(v, param, &p->max_cpu_throttle, &err);
-        break;
-    case MIGRATION_PARAMETER_TLS_CREDS:
-        p->tls_creds = g_new0(StrOrNull, 1);
-        p->tls_creds->type = QTYPE_QSTRING;
-        visit_type_str(v, param, &p->tls_creds->u.s, &err);
-        break;
-    case MIGRATION_PARAMETER_TLS_HOSTNAME:
-        p->tls_hostname = g_new0(StrOrNull, 1);
-        p->tls_hostname->type = QTYPE_QSTRING;
-        visit_type_str(v, param, &p->tls_hostname->u.s, &err);
-        break;
-    case MIGRATION_PARAMETER_TLS_AUTHZ:
-        p->tls_authz = g_new0(StrOrNull, 1);
-        p->tls_authz->type = QTYPE_QSTRING;
-        visit_type_str(v, param, &p->tls_authz->u.s, &err);
-        break;
-    case MIGRATION_PARAMETER_MAX_BANDWIDTH:
-        p->has_max_bandwidth = true;
-        visit_type_size(v, param, &p->max_bandwidth, &err);
-        break;
-    case MIGRATION_PARAMETER_AVAIL_SWITCHOVER_BANDWIDTH:
-        p->has_avail_switchover_bandwidth = true;
-        visit_type_size(v, param, &p->avail_switchover_bandwidth, &err);
-        break;
-    case MIGRATION_PARAMETER_DOWNTIME_LIMIT:
-        p->has_downtime_limit = true;
-        visit_type_size(v, param, &p->downtime_limit, &err);
-        break;
-    case MIGRATION_PARAMETER_X_CHECKPOINT_DELAY:
-        p->has_x_checkpoint_delay = true;
-        visit_type_uint32(v, param, &p->x_checkpoint_delay, &err);
-        break;
-    case MIGRATION_PARAMETER_MULTIFD_CHANNELS:
-        p->has_multifd_channels = true;
-        visit_type_uint8(v, param, &p->multifd_channels, &err);
-        break;
-    case MIGRATION_PARAMETER_MULTIFD_COMPRESSION:
-        p->has_multifd_compression = true;
-        visit_type_MultiFDCompression(v, param, &p->multifd_compression,
-                                      &err);
-        break;
-    case MIGRATION_PARAMETER_MULTIFD_ZLIB_LEVEL:
-        p->has_multifd_zlib_level = true;
-        visit_type_uint8(v, param, &p->multifd_zlib_level, &err);
-        break;
-    case MIGRATION_PARAMETER_MULTIFD_QATZIP_LEVEL:
-        p->has_multifd_qatzip_level = true;
-        visit_type_uint8(v, param, &p->multifd_qatzip_level, &err);
-        break;
-    case MIGRATION_PARAMETER_MULTIFD_ZSTD_LEVEL:
-        p->has_multifd_zstd_level = true;
-        visit_type_uint8(v, param, &p->multifd_zstd_level, &err);
-        break;
-    case MIGRATION_PARAMETER_ZERO_PAGE_DETECTION:
-        p->has_zero_page_detection = true;
-        visit_type_ZeroPageDetection(v, param, &p->zero_page_detection, &err);
-        break;
-    case MIGRATION_PARAMETER_XBZRLE_CACHE_SIZE:
-        p->has_xbzrle_cache_size = true;
-        if (!visit_type_size(v, param, &cache_size, &err)) {
-            break;
-        }
-        if (cache_size > INT64_MAX || (size_t)cache_size != cache_size) {
-            error_setg(&err, "Invalid size %s", valuestr);
-            break;
-        }
-        p->xbzrle_cache_size = cache_size;
-        break;
-    case MIGRATION_PARAMETER_MAX_POSTCOPY_BANDWIDTH:
-        p->has_max_postcopy_bandwidth = true;
-        visit_type_size(v, param, &p->max_postcopy_bandwidth, &err);
-        break;
-    case MIGRATION_PARAMETER_ANNOUNCE_INITIAL:
-        p->has_announce_initial = true;
-        visit_type_size(v, param, &p->announce_initial, &err);
-        break;
-    case MIGRATION_PARAMETER_ANNOUNCE_MAX:
-        p->has_announce_max = true;
-        visit_type_size(v, param, &p->announce_max, &err);
-        break;
-    case MIGRATION_PARAMETER_ANNOUNCE_ROUNDS:
-        p->has_announce_rounds = true;
-        visit_type_size(v, param, &p->announce_rounds, &err);
-        break;
-    case MIGRATION_PARAMETER_ANNOUNCE_STEP:
-        p->has_announce_step = true;
-        visit_type_size(v, param, &p->announce_step, &err);
-        break;
-    case MIGRATION_PARAMETER_BLOCK_BITMAP_MAPPING:
-        error_setg(&err, "The block-bitmap-mapping parameter can only be set "
-                   "through QMP");
-        break;
-    case MIGRATION_PARAMETER_X_VCPU_DIRTY_LIMIT_PERIOD:
-        p->has_x_vcpu_dirty_limit_period = true;
-        visit_type_size(v, param, &p->x_vcpu_dirty_limit_period, &err);
-        break;
-    case MIGRATION_PARAMETER_VCPU_DIRTY_LIMIT:
-        p->has_vcpu_dirty_limit = true;
-        visit_type_size(v, param, &p->vcpu_dirty_limit, &err);
-        break;
-    case MIGRATION_PARAMETER_MODE:
-        p->has_mode = true;
-        visit_type_MigMode(v, param, &p->mode, &err);
-        break;
-    case MIGRATION_PARAMETER_DIRECT_IO:
-        p->has_direct_io = true;
-        visit_type_bool(v, param, &p->direct_io, &err);
-        break;
-    case MIGRATION_PARAMETER_X_RDMA_CHUNK_SIZE:
-        p->has_x_rdma_chunk_size = true;
-        visit_type_size(v, param, &p->x_rdma_chunk_size, &err);
-        break;
-    case MIGRATION_PARAMETER_CPR_EXEC_COMMAND: {
+    if (g_str_equal(param, "cpr-exec-command")) {
         /*
          * NOTE: g_autofree will only auto g_free() the strv array when
          * needed, it will not free the strings within the array. It's
@@ -760,15 +622,14 @@ void hmp_migrate_set_parameter(MonitorHMP *hmp, const QDict *qdict)
 
         if (!g_shell_parse_argv(valuestr, NULL, &strv, &gerr)) {
             error_setg(&err, "%s", gerr->message);
-            break;
+            goto cleanup;
         }
         for (int i = 0; strv[i]; i++) {
             QAPI_LIST_APPEND(tail, strv[i]);
         }
         p->has_cpr_exec_command = true;
-        break;
-    }
-    default:
+
+    } else {
         g_assert_not_reached();
     }
 
@@ -778,12 +639,52 @@ void hmp_migrate_set_parameter(MonitorHMP *hmp, const QDict *qdict)
 
     qmp_migrate_set_parameters(p, &err);
 
- cleanup:
+cleanup:
     qapi_free_MigrationParameters(p);
+    hmp_handle_error(hmp, err);
+}
+
+static void hmp_migrate_set_parameter_qapi(MonitorHMP *hmp, const QDict *qdict)
+{
+    const char *param = qdict_get_str(qdict, "parameter");
+    const char *valuestr = qdict_get_str(qdict, "value");
+    g_autoptr(QDict) input = qdict_new();
+    g_autoptr(MigrationParameters) p = NULL;
+    Visitor *v;
+    Error *err = NULL;
+
+    /* the same as keyval_parse(), but here there's no need to parse */
+    qdict_put_obj(input, param, QOBJECT(qstring_from_str(valuestr)));
+
+    v = qobject_input_visitor_new_keyval(QOBJECT(input));
+    if (visit_type_MigrationParameters(v, NULL, &p, &err)) {
+        qmp_migrate_set_parameters(p, &err);
+    }
+
     visit_free(v);
     hmp_handle_error(hmp, err);
 }
 
+void hmp_migrate_set_parameter(MonitorHMP *hmp, const QDict *qdict)
+{
+    const char *param = qdict_get_str(qdict, "parameter");
+
+    if (g_str_equal(param, "block-bitmap-mapping")) {
+        Error *err = NULL;
+
+        error_setg(&err, "The %s parameter can only be set through QMP", param);
+        hmp_handle_error(hmp, err);
+        return;
+    }
+
+    /* this has a non-standard setter */
+    if (g_str_equal(param, "cpr-exec-command")) {
+        return hmp_migrate_set_parameter_legacy(hmp, qdict);
+    }
+
+    hmp_migrate_set_parameter_qapi(hmp, qdict);
+}
+
 void hmp_migrate_start_postcopy(MonitorHMP *hmp, const QDict *qdict)
 {
     Error *err = NULL;
diff --git a/tests/qtest/migration/misc-tests.c b/tests/qtest/migration/misc-tests.c
index 2261ae7c89..4ac2f42a5a 100644
--- a/tests/qtest/migration/misc-tests.c
+++ b/tests/qtest/migration/misc-tests.c
@@ -50,7 +50,7 @@ typedef struct HMPTestData {
 HMPTestData test_cases[] = {
     TEST("", "", "migrate_set_parameter: string expected"),
     TEST("foo", "", "migrate_set_parameter: string expected"),
-    TEST("foo", "on", "Error: invalid parameter value: foo"),
+    TEST("foo", "on", "Error: Parameter 'foo' is unexpected"),
 
     /* bool */
     TEST("cpu-throttle-tailslow", "on", "on"),
-- 
2.53.0