[Qemu-devel] [RFC PATCH v2 21/49] sysemu: system functions for replay

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

This patch removes "static" specifier from several qemu function to make
them visible to the replay module. It also invents several system functions
that will be used by replay.

Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru>
---
 arch_init.c             |    8 ++++++++
 cpu-exec.c              |    6 ++++--
 cpus.c                  |    4 ++--
 include/exec/exec-all.h |    4 +++-
 include/sysemu/cpus.h   |    1 +
 include/sysemu/sysemu.h |    1 +
 savevm.c                |   32 ++++++++++++++++++++++++++------
 translate-all.c         |    8 ++++++++
 8 files changed, 53 insertions(+), 11 deletions(-)

diff --git a/arch_init.c b/arch_init.c
index 8ddaf35..5ee33d9 100644
--- a/arch_init.c
+++ b/arch_init.c
@@ -52,6 +52,7 @@
 #include "exec/ram_addr.h"
 #include "hw/acpi/acpi.h"
 #include "qemu/host-utils.h"
+#include "replay/replay.h"
 
 #ifdef DEBUG_ARCH_INIT
 #define DPRINTF(fmt, ...) \
@@ -1092,6 +1093,13 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id)
 
                 total_ram_bytes -= length;
             }
+            if (replay_mode == REPLAY_PLAY) {
+                RAMBlock *block;
+                /* Clear the blocks' memory instead of resetting the machine */
+                QTAILQ_FOREACH(block, &ram_list.blocks, next) {
+                    memset(block->host, 0, block->length);
+                }
+            }
         } else if (flags & RAM_SAVE_FLAG_COMPRESS) {
             void *host;
             uint8_t ch;
diff --git a/cpu-exec.c b/cpu-exec.c
index 38e5f02..66a693c 100644
--- a/cpu-exec.c
+++ b/cpu-exec.c
@@ -189,12 +189,14 @@ static inline TranslationBlock *tb_find_fast(CPUArchState *env)
 
 static CPUDebugExcpHandler *debug_excp_handler;
 
-void cpu_set_debug_excp_handler(CPUDebugExcpHandler *handler)
+CPUDebugExcpHandler *cpu_set_debug_excp_handler(CPUDebugExcpHandler *handler)
 {
+    CPUDebugExcpHandler *old = debug_excp_handler;
     debug_excp_handler = handler;
+    return old;
 }
 
-static void cpu_handle_debug_exception(CPUArchState *env)
+void cpu_handle_debug_exception(CPUArchState *env)
 {
     CPUState *cpu = ENV_GET_CPU(env);
     CPUWatchpoint *wp;
diff --git a/cpus.c b/cpus.c
index 5e7f2cf..bbad529 100644
--- a/cpus.c
+++ b/cpus.c
@@ -85,7 +85,7 @@ static bool cpu_thread_is_idle(CPUState *cpu)
     return true;
 }
 
-static bool all_cpu_threads_idle(void)
+bool all_cpu_threads_idle(void)
 {
     CPUState *cpu;
 
@@ -1033,7 +1033,7 @@ bool qemu_cpu_is_self(CPUState *cpu)
     return qemu_thread_is_self(cpu->thread);
 }
 
-static bool qemu_in_vcpu_thread(void)
+bool qemu_in_vcpu_thread(void)
 {
     return current_cpu && qemu_cpu_is_self(current_cpu);
 }
diff --git a/include/exec/exec-all.h b/include/exec/exec-all.h
index 528928f..4b7a241 100644
--- a/include/exec/exec-all.h
+++ b/include/exec/exec-all.h
@@ -212,6 +212,7 @@ static inline unsigned int tb_phys_hash_func(tb_page_addr_t pc)
 
 void tb_free(TranslationBlock *tb);
 void tb_flush(CPUArchState *env);
+void tb_flush_all(void);
 void tb_phys_invalidate(TranslationBlock *tb, tb_page_addr_t page_addr);
 
 #if defined(USE_DIRECT_JUMP)
@@ -385,7 +386,8 @@ tb_page_addr_t get_page_addr_code(CPUArchState *env1, target_ulong addr);
 
 typedef void (CPUDebugExcpHandler)(CPUArchState *env);
 
-void cpu_set_debug_excp_handler(CPUDebugExcpHandler *handler);
+CPUDebugExcpHandler *cpu_set_debug_excp_handler(CPUDebugExcpHandler *handler);
+void cpu_handle_debug_exception(CPUArchState *env);
 
 /* vl.c */
 extern int singlestep;
diff --git a/include/sysemu/cpus.h b/include/sysemu/cpus.h
index 4f79081..8455e0e 100644
--- a/include/sysemu/cpus.h
+++ b/include/sysemu/cpus.h
@@ -6,6 +6,7 @@ void qemu_init_cpu_loop(void);
 void resume_all_vcpus(void);
 void pause_all_vcpus(void);
 void cpu_stop_current(void);
+bool all_cpu_threads_idle(void);
 
 void cpu_synchronize_all_states(void);
 void cpu_synchronize_all_post_reset(void);
diff --git a/include/sysemu/sysemu.h b/include/sysemu/sysemu.h
index d8539fd..1ebfef9 100644
--- a/include/sysemu/sysemu.h
+++ b/include/sysemu/sysemu.h
@@ -76,6 +76,7 @@ void qemu_add_machine_init_done_notifier(Notifier *notify);
 
 void do_savevm(Monitor *mon, const QDict *qdict);
 int load_vmstate(const char *name);
+int save_vmstate(Monitor *mon, const char *name);
 void do_delvm(Monitor *mon, const QDict *qdict);
 void do_info_snapshots(Monitor *mon, const QDict *qdict);
 
diff --git a/savevm.c b/savevm.c
index e19ae0a..9136778 100644
--- a/savevm.c
+++ b/savevm.c
@@ -42,7 +42,7 @@
 #include "qemu/iov.h"
 #include "block/snapshot.h"
 #include "block/qapi.h"
-
+#include "replay/replay.h"
 
 #ifndef ETH_P_RARP
 #define ETH_P_RARP 0x8035
@@ -1039,7 +1039,7 @@ static int del_existing_snapshots(Monitor *mon, const char *name)
     return 0;
 }
 
-void do_savevm(Monitor *mon, const QDict *qdict)
+int save_vmstate(Monitor *mon, const char *name)
 {
     BlockDriverState *bs, *bs1;
     QEMUSnapshotInfo sn1, *sn = &sn1, old_sn1, *old_sn = &old_sn1;
@@ -1049,7 +1049,7 @@ void do_savevm(Monitor *mon, const QDict *qdict)
     uint64_t vm_state_size;
     qemu_timeval tv;
     struct tm tm;
-    const char *name = qdict_get_try_str(qdict, "name");
+    int success = 0;
 
     /* Verify if there is a device that doesn't support snapshots and is writable */
     bs = NULL;
@@ -1062,14 +1062,18 @@ void do_savevm(Monitor *mon, const QDict *qdict)
         if (!bdrv_can_snapshot(bs)) {
             monitor_printf(mon, "Device '%s' is writable but does not support snapshots.\n",
                                bdrv_get_device_name(bs));
-            return;
+            return success;
         }
     }
 
     bs = find_vmstate_bs();
     if (!bs) {
         monitor_printf(mon, "No block device can accept snapshots\n");
-        return;
+        if (replay_mode != REPLAY_NONE) {
+            fprintf(stderr, "At least one hdd should be attached to QEMU for replay\n");
+            exit(1);
+        }
+        return success;
     }
 
     saved_vm_running = runstate_is_running();
@@ -1118,6 +1122,7 @@ void do_savevm(Monitor *mon, const QDict *qdict)
 
     /* create the snapshots */
 
+    success = 1;
     bs1 = NULL;
     while ((bs1 = bdrv_next(bs1))) {
         if (bdrv_can_snapshot(bs1)) {
@@ -1127,6 +1132,7 @@ void do_savevm(Monitor *mon, const QDict *qdict)
             if (ret < 0) {
                 monitor_printf(mon, "Error while creating snapshot on '%s'\n",
                                bdrv_get_device_name(bs1));
+                success = 0;
             }
         }
     }
@@ -1135,6 +1141,14 @@ void do_savevm(Monitor *mon, const QDict *qdict)
     if (saved_vm_running) {
         vm_start();
     }
+
+    return success;
+}
+
+void do_savevm(Monitor *mon, const QDict *qdict)
+{
+    const char *name = qdict_get_try_str(qdict, "name");
+    save_vmstate(mon, name);
 }
 
 void qmp_xen_save_devices_state(const char *filename, Error **errp)
@@ -1231,7 +1245,13 @@ int load_vmstate(const char *name)
         return -EINVAL;
     }
 
-    qemu_system_reset(VMRESET_SILENT);
+    /* Do not reset in replay mode.
+       1. Reset will alter the behavior in play mode compared to save one
+       2. Timers read by reset handlers are not correct, because
+          replay reads them from the unknown part of the log */
+    if (replay_mode == REPLAY_NONE) {
+        qemu_system_reset(VMRESET_SILENT);
+    }
     ret = qemu_loadvm_state(f);
 
     qemu_fclose(f);
diff --git a/translate-all.c b/translate-all.c
index 8f7e11b..fcb0697 100644
--- a/translate-all.c
+++ b/translate-all.c
@@ -803,6 +803,14 @@ void tb_flush(CPUArchState *env1)
     tcg_ctx.tb_ctx.tb_flush_count++;
 }
 
+void tb_flush_all(void)
+{
+    CPUState *cpu;
+    for (cpu = first_cpu ; cpu != NULL ; cpu = CPU_NEXT(cpu)) {
+        tb_flush(cpu->env_ptr);
+    }
+}
+
 #ifdef DEBUG_TB_CHECK
 
 static void tb_invalidate_check(target_ulong address)