[PATCH v4 3/3] replay: do not build if TCG is not available

[Claudio Fontana]

this fixes non-TCG builds broken recently by replay reverse debugging.

stub the needed functions in stub/, including errors for hmp and qmp.
This includes duplicating some code in replay/, and puts the logic
for non-replay related events in the replay/ module (+ the stubs),
so this should be revisited in the future.

Surprisingly, only _one_ qtest was affected by this, ide-test.c, which
resulted in a buzz as the bh events were never delivered, and the bh
never executed.

Many other subsystems _should_ have been affected.

This fixes the immediate issue, however a better way to group replay
functionality to TCG-only code could be developed in the long term.

Signed-off-by: Claudio Fontana <cfontana@suse.de>
---
 block/meson.build          |  3 +-
 migration/savevm.c         | 11 +++--
 net/meson.build            |  3 +-
 replay/meson.build         |  2 +-
 replay/replay-input.c      |  4 +-
 stubs/meson.build          |  1 -
 stubs/replay-user.c        |  9 ----
 stubs/replay.c             | 98 ++++++++++++++++++++++++++++++++++++++
 tests/ptimer-test-stubs.c  |  5 --
 tests/qtest/qmp-cmd-test.c |  3 ++
 ui/input.c                 | 12 ++++-
 11 files changed, 125 insertions(+), 26 deletions(-)
 delete mode 100644 stubs/replay-user.c

diff --git a/block/meson.build b/block/meson.build
index 78e8b25232..01fe6f84d2 100644
--- a/block/meson.build
+++ b/block/meson.build
@@ -7,7 +7,6 @@ block_ss.add(files(
   'backup-top.c',
   'blkdebug.c',
   'blklogwrites.c',
-  'blkreplay.c',
   'blkverify.c',
   'block-backend.c',
   'block-copy.c',
@@ -42,6 +41,8 @@ block_ss.add(files(
   'write-threshold.c',
 ), zstd, zlib)
 
+block_ss.add(when: 'CONFIG_TCG', if_true: files('blkreplay.c'))
+
 block_ss.add(when: 'CONFIG_QCOW1', if_true: files('qcow.c'))
 block_ss.add(when: 'CONFIG_VDI', if_true: files('vdi.c'))
 block_ss.add(when: 'CONFIG_CLOOP', if_true: files('cloop.c'))
diff --git a/migration/savevm.c b/migration/savevm.c
index d2e141f7b1..d9181ca520 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -63,6 +63,7 @@
 #include "migration/colo.h"
 #include "qemu/bitmap.h"
 #include "net/announce.h"
+#include "sysemu/tcg.h"
 
 const unsigned int postcopy_ram_discard_version = 0;
 
@@ -2674,10 +2675,12 @@ int save_snapshot(const char *name, Error **errp)
         return ret;
     }
 
-    if (!replay_can_snapshot()) {
-        error_setg(errp, "Record/replay does not allow making snapshot "
-                   "right now. Try once more later.");
-        return ret;
+    if (tcg_enabled()) {
+        if (!replay_can_snapshot()) {
+            error_setg(errp, "Record/replay does not allow making snapshot "
+                       "right now. Try once more later.");
+            return ret;
+        }
     }
 
     if (!bdrv_all_can_snapshot(&bs)) {
diff --git a/net/meson.build b/net/meson.build
index 1c7e3a3cb9..1076b0a7ab 100644
--- a/net/meson.build
+++ b/net/meson.build
@@ -7,7 +7,6 @@ softmmu_ss.add(files(
   'eth.c',
   'filter-buffer.c',
   'filter-mirror.c',
-  'filter-replay.c',
   'filter-rewriter.c',
   'filter.c',
   'hub.c',
@@ -17,6 +16,8 @@ softmmu_ss.add(files(
   'util.c',
 ))
 
+softmmu_ss.add(when: 'CONFIG_TCG', if_true: files('filter-replay.c'))
+
 softmmu_ss.add(when: 'CONFIG_L2TPV3', if_true: files('l2tpv3.c'))
 softmmu_ss.add(when: slirp, if_true: files('slirp.c'))
 softmmu_ss.add(when: ['CONFIG_VDE', vde], if_true: files('vde.c'))
diff --git a/replay/meson.build b/replay/meson.build
index f91163fb1e..cb3207740a 100644
--- a/replay/meson.build
+++ b/replay/meson.build
@@ -1,4 +1,4 @@
-softmmu_ss.add(files(
+softmmu_ss.add(when: 'CONFIG_TCG', if_true: files(
   'replay.c',
   'replay-internal.c',
   'replay-events.c',
diff --git a/replay/replay-input.c b/replay/replay-input.c
index 1147e3d34e..5d1fd92e79 100644
--- a/replay/replay-input.c
+++ b/replay/replay-input.c
@@ -124,7 +124,7 @@ void replay_input_event(QemuConsole *src, InputEvent *evt)
     } else if (replay_mode == REPLAY_MODE_RECORD) {
         replay_add_input_event(QAPI_CLONE(InputEvent, evt));
     } else {
-        qemu_input_event_send_impl(src, evt);
+        g_assert_not_reached();
     }
 }
 
@@ -135,6 +135,6 @@ void replay_input_sync_event(void)
     } else if (replay_mode == REPLAY_MODE_RECORD) {
         replay_add_input_sync_event();
     } else {
-        qemu_input_event_sync_impl();
+        g_assert_not_reached();
     }
 }
diff --git a/stubs/meson.build b/stubs/meson.build
index 67f2a8c069..bbd2230d69 100644
--- a/stubs/meson.build
+++ b/stubs/meson.build
@@ -32,7 +32,6 @@ stub_ss.add(files('qtest.c'))
 stub_ss.add(files('ram-block.c'))
 stub_ss.add(files('ramfb.c'))
 stub_ss.add(files('replay.c'))
-stub_ss.add(files('replay-user.c'))
 stub_ss.add(files('runstate-check.c'))
 stub_ss.add(files('set-fd-handler.c'))
 stub_ss.add(files('sysbus.c'))
diff --git a/stubs/replay-user.c b/stubs/replay-user.c
deleted file mode 100644
index 2ad9e27203..0000000000
--- a/stubs/replay-user.c
+++ /dev/null
@@ -1,9 +0,0 @@
-#include "qemu/osdep.h"
-#include "sysemu/replay.h"
-#include "sysemu/sysemu.h"
-
-void replay_bh_schedule_oneshot_event(AioContext *ctx,
-    QEMUBHFunc *cb, void *opaque)
-{
-    aio_bh_schedule_oneshot(ctx, cb, opaque);
-}
diff --git a/stubs/replay.c b/stubs/replay.c
index 45ebe77fb9..34b7975b2d 100644
--- a/stubs/replay.c
+++ b/stubs/replay.c
@@ -103,3 +103,101 @@ bool replay_reverse_continue(void)
 {
     return false;
 }
+
+void replay_input_event(QemuConsole *src, InputEvent *evt)
+{
+}
+void replay_input_sync_event(void)
+{
+}
+void replay_bh_schedule_event(QEMUBH *bh)
+{
+    qemu_bh_schedule(bh);
+}
+void replay_bh_schedule_oneshot_event(AioContext *ctx,
+     QEMUBHFunc *cb, void *opaque)
+{
+    aio_bh_schedule_oneshot(ctx, cb, opaque);
+}
+void replay_add_blocker(Error *reason)
+{
+}
+void replay_audio_in(size_t *recorded, void *samples, size_t *wpos, size_t 
size)
+{
+}
+void replay_audio_out(size_t *played)
+{
+}
+void replay_breakpoint(void)
+{
+}
+bool replay_can_snapshot(void)
+{
+    return false;
+}
+void replay_configure(struct QemuOpts *opts)
+{
+}
+void replay_flush_events(void)
+{
+}
+void replay_gdb_attached(void)
+{
+}
+bool replay_running_debug(void)
+{
+    return false;
+}
+void replay_shutdown_request(ShutdownCause cause)
+{
+}
+void replay_start(void)
+{
+}
+void replay_vmstate_init(void)
+{
+}
+
+#include "monitor/monitor.h"
+#include "monitor/hmp.h"
+#include "qapi/qapi-commands-replay.h"
+#include "qapi/error.h"
+#include "qemu/error-report.h"
+
+void hmp_info_replay(Monitor *mon, const QDict *qdict)
+{
+    error_report("replay support not available");
+}
+void hmp_replay_break(Monitor *mon, const QDict *qdict)
+{
+    error_report("replay support not available");
+}
+void hmp_replay_delete_break(Monitor *mon, const QDict *qdict)
+{
+    error_report("replay support not available");
+}
+void hmp_replay_seek(Monitor *mon, const QDict *qdict)
+{
+    error_report("replay support not available");
+}
+ReplayInfo *qmp_query_replay(Error **errp)
+{
+    error_set(errp, ERROR_CLASS_COMMAND_NOT_FOUND,
+              "replay support not available");
+    return NULL;
+}
+void qmp_replay_break(int64_t icount, Error **errp)
+{
+    error_set(errp, ERROR_CLASS_COMMAND_NOT_FOUND,
+              "replay support not available");
+}
+void qmp_replay_delete_break(Error **errp)
+{
+    error_set(errp, ERROR_CLASS_COMMAND_NOT_FOUND,
+              "replay support not available");
+}
+void qmp_replay_seek(int64_t icount, Error **errp)
+{
+    error_set(errp, ERROR_CLASS_COMMAND_NOT_FOUND,
+              "replay support not available");
+}
diff --git a/tests/ptimer-test-stubs.c b/tests/ptimer-test-stubs.c
index e935a1395e..7f801a4d09 100644
--- a/tests/ptimer-test-stubs.c
+++ b/tests/ptimer-test-stubs.c
@@ -122,8 +122,3 @@ void qemu_bh_delete(QEMUBH *bh)
 {
     g_free(bh);
 }
-
-void replay_bh_schedule_event(QEMUBH *bh)
-{
-    bh->cb(bh->opaque);
-}
diff --git a/tests/qtest/qmp-cmd-test.c b/tests/qtest/qmp-cmd-test.c
index 8a4c570e83..1c7186e53c 100644
--- a/tests/qtest/qmp-cmd-test.c
+++ b/tests/qtest/qmp-cmd-test.c
@@ -31,6 +31,9 @@ static int query_error_class(const char *cmd)
 #ifndef CONFIG_SPICE
         { "query-spice", ERROR_CLASS_COMMAND_NOT_FOUND },
 #endif
+#ifndef CONFIG_TCG
+        { "query-replay", ERROR_CLASS_COMMAND_NOT_FOUND },
+#endif
 #ifndef CONFIG_VNC
         { "query-vnc", ERROR_CLASS_GENERIC_ERROR },
         { "query-vnc-servers", ERROR_CLASS_GENERIC_ERROR },
diff --git a/ui/input.c b/ui/input.c
index 4791b089c7..8675e8ad09 100644
--- a/ui/input.c
+++ b/ui/input.c
@@ -375,7 +375,11 @@ void qemu_input_event_send(QemuConsole *src, InputEvent 
*evt)
         return;
     }
 
-    replay_input_event(src, evt);
+    if (replay_events_enabled()) {
+        replay_input_event(src, evt);
+    } else {
+        qemu_input_event_send_impl(src, evt);
+    }
 }
 
 void qemu_input_event_sync_impl(void)
@@ -401,7 +405,11 @@ void qemu_input_event_sync(void)
         return;
     }
 
-    replay_input_sync_event();
+    if (replay_events_enabled()) {
+        replay_input_sync_event();
+    } else {
+        qemu_input_event_sync_impl();
+    }
 }
 
 static InputEvent *qemu_input_event_new_key(KeyValue *key, bool down)
-- 
2.26.2