[Qemu-devel] [RFC PATCH v2 37/49] replay: initialization and deinitialization

[Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru>]

This patch introduces the functions for enabling the record/replay and for
freeing the resources when simulator closes.

Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru>
---
 exec.c                   |    1 
 replay/replay-internal.h |    2 +
 replay/replay.c          |  127 ++++++++++++++++++++++++++++++++++++++++++++++
 replay/replay.h          |   11 ++++
 vl.c                     |    5 ++
 5 files changed, 146 insertions(+), 0 deletions(-)

diff --git a/exec.c b/exec.c
index 36adb62..050e0a8 100644
--- a/exec.c
+++ b/exec.c
@@ -732,6 +732,7 @@ void cpu_abort(CPUState *cpu, const char *fmt, ...)
     }
     va_end(ap2);
     va_end(ap);
+    replay_finish();
 #if defined(CONFIG_USER_ONLY)
     {
         struct sigaction act;
diff --git a/replay/replay-internal.h b/replay/replay-internal.h
index 3f97fd7..7e5b3af 100755
--- a/replay/replay-internal.h
+++ b/replay/replay-internal.h
@@ -36,6 +36,8 @@
 
 /* for checkpoint event */
 #define EVENT_CHECKPOINT            96
+/* end of log event */
+#define EVENT_END                   127
 
 /* Asynchronous events IDs */
 
diff --git a/replay/replay.c b/replay/replay.c
index 225d8ec..c583bb4 100755
--- a/replay/replay.c
+++ b/replay/replay.c
@@ -13,10 +13,18 @@
 #include "replay.h"
 #include "replay-internal.h"
 
+/* Current version of the replay mechanism.
+   Increase it when file format changes. */
+#define REPLAY_VERSION              0xe02001
+/* Size of replay log header */
+#define HEADER_SIZE                 (sizeof(uint32_t) + sizeof(uint64_t))
+
 int replay_mode = REPLAY_NONE;
 /*! Stores current submode for PLAY mode */
 int play_submode = REPLAY_PLAY_UNKNOWN;
 
+/* Name of replay file  */
+static char *replay_filename;
 /* Suffix for the disk images filenames */
 char *replay_image_suffix;
 
@@ -240,3 +248,122 @@ int replay_checkpoint(unsigned int checkpoint)
 
     return 1;
 }
+
+static void replay_enable(const char *fname, int mode)
+{
+    const char *fmode = NULL;
+    if (replay_file) {
+        fprintf(stderr, "Replay: some record/replay operation is already started\n");
+        return;
+    }
+
+    switch (mode) {
+    case REPLAY_SAVE:
+        fmode = "wb";
+        break;
+    case REPLAY_PLAY:
+        fmode = "rb";
+        play_submode = REPLAY_PLAY_NORMAL;
+        break;
+    default:
+        fprintf(stderr, "Replay: internal error: invalid replay mode\n");
+        exit(1);
+    }
+
+    atexit(replay_finish);
+
+    replay_file = fopen(fname, fmode);
+    if (replay_file == NULL) {
+        fprintf(stderr, "Replay: open %s: %s\n", fname, strerror(errno));
+        exit(1);
+    }
+
+    replay_filename = g_strdup(fname);
+
+    replay_mode = mode;
+    replay_has_unread_data = 0;
+    replay_data_kind = -1;
+    replay_state.skipping_instruction = 0;
+    replay_state.current_step = 0;
+
+    /* skip file header for SAVE and check it for PLAY */
+    if (replay_mode == REPLAY_SAVE) {
+        fseek(replay_file, HEADER_SIZE, SEEK_SET);
+    } else if (replay_mode == REPLAY_PLAY) {
+        unsigned int version = replay_get_dword();
+        uint64_t offset = replay_get_qword();
+        if (version != REPLAY_VERSION) {
+            fprintf(stderr, "Replay: invalid input log file version\n");
+            exit(1);
+        }
+        /* go to the beginning */
+        fseek(replay_file, 12, SEEK_SET);
+    }
+
+    replay_init_events();
+}
+
+void replay_configure(QemuOpts *opts, int mode)
+{
+    const char *fname;
+    
+    fname = qemu_opt_get(opts, "fname");
+    if (!fname) {
+        fprintf(stderr, "File name not specified for replay\n");
+        exit(1);
+    }
+
+    const char *suffix = qemu_opt_get(opts, "suffix");
+    if (suffix) {
+        replay_image_suffix = g_strdup(suffix);
+    } else {
+        replay_image_suffix = g_strdup("replay_qcow");
+    }
+
+    replay_enable(fname, mode);
+}
+
+void replay_init_timer(void)
+{
+    if (replay_mode == REPLAY_NONE) {
+        return;
+    }
+
+    replay_enable_events();
+}
+
+void replay_finish(void)
+{
+    if (replay_mode == REPLAY_NONE) {
+        return;
+    }
+
+    replay_save_instructions();
+
+    /* finalize the file */
+    if (replay_file) {
+        if (replay_mode == REPLAY_SAVE) {
+            uint64_t offset = 0;
+            /* write end event */
+            replay_put_event(EVENT_END);
+
+            /* write header */
+            fseek(replay_file, 0, SEEK_SET);
+            replay_put_dword(REPLAY_VERSION);
+            replay_put_qword(offset);
+        }
+
+        fclose(replay_file);
+        replay_file = NULL;
+    }
+    if (replay_filename) {
+        g_free(replay_filename);
+        replay_filename = NULL;
+    }
+    if (replay_image_suffix) {
+        g_free(replay_image_suffix);
+        replay_image_suffix = NULL;
+    }
+
+    replay_finish_events();
+}
diff --git a/replay/replay.h b/replay/replay.h
index e96c74f..e066cb2 100755
--- a/replay/replay.h
+++ b/replay/replay.h
@@ -16,6 +16,8 @@
 #include <stdint.h>
 #include <time.h>
 
+struct QemuOpts;
+
 /* replay modes */
 #define REPLAY_NONE 0
 #define REPLAY_SAVE 1
@@ -43,6 +45,15 @@ extern int replay_icount;
 /*! Returns replay play submode */
 int replay_get_play_submode(void);
 
+/* Replay process control functions */
+
+/*! Enables recording or saving event log with specified parameters */
+void replay_configure(struct QemuOpts *opts, int mode);
+/*! Initializes timers used for snapshotting and enables events recording */
+void replay_init_timer(void);
+/*! Closes replay log file and frees other resources. */
+void replay_finish(void);
+
 /* Processing the instructions */
 
 /*! Returns number of executed instructions. */
diff --git a/vl.c b/vl.c
index 053b2ba..6050faf 100644
--- a/vl.c
+++ b/vl.c
@@ -4544,7 +4544,12 @@ int main(int argc, char **argv, char **envp)
         }
     }
 
+    replay_init_timer();
+
     main_loop();
+    if (replay_mode != REPLAY_NONE) {
+        replay_disable_events();
+    }
     bdrv_close_all();
     pause_all_vcpus();
     res_free();