replay: do not build if TCG is not available

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

Stub the needed functions in stub/, splitting roughly between functions
needed only by system emulation, by system emulation and tools,
and by everyone.  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>
Message-Id: <20201013192123.22632-4-cfontana@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

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)
 
+softmmu_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'))

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'))

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',
@@ -10,4 +10,4 @@ softmmu_ss.add(files(
   'replay-audio.c',
   'replay-random.c',
   'replay-debugging.c',
-))
+), if_false: files('stubs-system.c'))

replay/stubs-system.c

@@ -0,0 +1,96 @@
+#include "qemu/osdep.h"
+#include "sysemu/replay.h"
+#include "ui/input.h"
+
+void replay_input_event(QemuConsole *src, InputEvent *evt)
+{
+    qemu_input_event_send_impl(src, evt);
+}
+
+void replay_input_sync_event(void)
+{
+    qemu_input_event_sync_impl();
+}
+
+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 true;
+}
+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");
+}

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'))
@@ -46,6 +45,9 @@ stub_ss.add(files('vmstate.c'))
 stub_ss.add(files('vm-stop.c'))
 stub_ss.add(files('win32-kbd-hook.c'))
 stub_ss.add(files('cpu-synchronize-state.c'))
+if have_block
+  stub_ss.add(files('replay-tools.c'))
+endif
 if have_system
   stub_ss.add(files('semihost.c'))
   stub_ss.add(files('xen-hw-stub.c'))

stubs/replay-tools.c

@@ -0,0 +1,83 @@
+#include "qemu/osdep.h"
+#include "sysemu/replay.h"
+#include "block/aio.h"
+
+bool replay_events_enabled(void)
+{
+    return false;
+}
+
+int64_t replay_save_clock(unsigned int kind, int64_t clock, int64_t raw_icount)
+{
+    abort();
+    return 0;
+}
+
+int64_t replay_read_clock(unsigned int kind)
+{
+    abort();
+    return 0;
+}
+
+uint64_t replay_get_current_icount(void)
+{
+    return 0;
+}
+
+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);
+}
+
+bool replay_checkpoint(ReplayCheckpoint checkpoint)
+{
+    return true;
+}
+
+void replay_mutex_lock(void)
+{
+}
+
+void replay_mutex_unlock(void)
+{
+}
+
+void replay_register_char_driver(Chardev *chr)
+{
+}
+
+void replay_chr_be_write(Chardev *s, uint8_t *buf, int len)
+{
+    abort();
+}
+
+void replay_char_write_event_save(int res, int offset)
+{
+    abort();
+}
+
+void replay_char_write_event_load(int *res, int *offset)
+{
+    abort();
+}
+
+int replay_char_read_all_load(uint8_t *buf)
+{
+    abort();
+}
+
+void replay_char_read_all_save_error(int res)
+{
+    abort();
+}
+
+void replay_char_read_all_save_buf(uint8_t *buf, int offset)
+{
+    abort();
+}

stubs/replay-user.c

@@ -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);
-}

stubs/replay.c

@@ -3,83 +3,10 @@
 
 ReplayMode replay_mode;
 
-int64_t replay_save_clock(unsigned int kind, int64_t clock, int64_t raw_icount)
-{
-    abort();
-    return 0;
-}
-
-int64_t replay_read_clock(unsigned int kind)
-{
-    abort();
-    return 0;
-}
-
-bool replay_checkpoint(ReplayCheckpoint checkpoint)
-{
-    return true;
-}
-
-bool replay_events_enabled(void)
-{
-    return false;
-}
-
 void replay_finish(void)
 {
 }
 
-void replay_register_char_driver(Chardev *chr)
-{
-}
-
-void replay_chr_be_write(Chardev *s, uint8_t *buf, int len)
-{
-    abort();
-}
-
-void replay_char_write_event_save(int res, int offset)
-{
-    abort();
-}
-
-void replay_char_write_event_load(int *res, int *offset)
-{
-    abort();
-}
-
-int replay_char_read_all_load(uint8_t *buf)
-{
-    abort();
-}
-
-void replay_char_read_all_save_error(int res)
-{
-    abort();
-}
-
-void replay_char_read_all_save_buf(uint8_t *buf, int offset)
-{
-    abort();
-}
-
-void replay_block_event(QEMUBH *bh, uint64_t id)
-{
-}
-
-uint64_t blkreplay_next_id(void)
-{
-    return 0;
-}
-
-void replay_mutex_lock(void)
-{
-}
-
-void replay_mutex_unlock(void)
-{
-}
-
 void replay_save_random(int ret, void *buf, size_t len)
 {
 }
@@ -89,11 +16,6 @@ int replay_read_random(void *buf, size_t len)
     return 0;
 }
 
-uint64_t replay_get_current_icount(void)
-{
-    return 0;
-}
-
 bool replay_reverse_step(void)
 {
     return false;

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);
-}

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 },