diff --git a/accel/tcg/tcg-runtime.c b/accel/tcg/tcg-runtime.c
index d852381c60..7a1a189cdd 100644
--- a/accel/tcg/tcg-runtime.c
+++ b/accel/tcg/tcg-runtime.c
@@ -39,99 +39,6 @@
 
 #include "libafl/exit.h"
 
-#ifndef CONFIG_USER_ONLY
-
-#include "sysemu/runstate.h"
-#include "migration/snapshot.h"
-#include "qapi/error.h"
-#include "qemu/error-report.h"
-#include "qemu/main-loop.h"
-#include "hw/core/cpu.h"
-#include "sysemu/hw_accel.h"
-#include <stdlib.h>
-#include <string.h>
-
-void libafl_save_qemu_snapshot(char *name, bool sync);
-void libafl_load_qemu_snapshot(char *name, bool sync);
-
-static void save_snapshot_cb(void* opaque)
-{
-    char* name = (char*)opaque;
-    Error *err = NULL;
-    if(!save_snapshot(name, true, NULL, false, NULL, &err)) {
-        error_report_err(err);
-        error_report("Could not save snapshot");
-    }
-    free(opaque);
-}
-
-void libafl_save_qemu_snapshot(char *name, bool sync)
-{
-    // use snapshots synchronously, use if main loop is not running
-    if (sync) {
-        //TODO: eliminate this code duplication
-        //by passing a heap-allocated buffer from rust to c,
-        //which c needs to free
-        Error *err = NULL;
-        if(!save_snapshot(name, true, NULL, false, NULL, &err)) {
-            error_report_err(err);
-            error_report("Could not save snapshot");
-        }
-        return;
-    }
-    char* name_buffer = malloc(strlen(name)+1);
-    strcpy(name_buffer, name);
-    aio_bh_schedule_oneshot_full(qemu_get_aio_context(), save_snapshot_cb, (void*)name_buffer, "save_snapshot");
-}
-
-static void load_snapshot_cb(void* opaque)
-{
-    char* name = (char*)opaque;
-    Error *err = NULL;
-
-    int saved_vm_running = runstate_is_running();
-    vm_stop(RUN_STATE_RESTORE_VM);
-
-    bool loaded = load_snapshot(name, NULL, false, NULL, &err);
-
-    if(!loaded) {
-        error_report_err(err);
-        error_report("Could not load snapshot");
-    }
-    if (loaded && saved_vm_running) {
-        vm_start();
-    }
-    free(opaque);
-}
-
-void libafl_load_qemu_snapshot(char *name, bool sync)
-{
-    // use snapshots synchronously, use if main loop is not running
-    if (sync) {
-        //TODO: see libafl_save_qemu_snapshot
-        Error *err = NULL;
-
-        int saved_vm_running = runstate_is_running();
-        vm_stop(RUN_STATE_RESTORE_VM);
-
-        bool loaded = load_snapshot(name, NULL, false, NULL, &err);
-
-        if(!loaded) {
-            error_report_err(err);
-            error_report("Could not load snapshot");
-        }
-        if (loaded && saved_vm_running) {
-            vm_start();
-        }
-        return;
-    }
-    char* name_buffer = malloc(strlen(name)+1);
-    strcpy(name_buffer, name);
-    aio_bh_schedule_oneshot_full(qemu_get_aio_context(), load_snapshot_cb, (void*)name_buffer, "load_snapshot");
-}
-
-#endif
-
 void HELPER(libafl_qemu_handle_breakpoint)(CPUArchState *env, uint64_t pc)
 {
     CPUState* cpu = env_cpu(env);
diff --git a/cpu-target.c b/cpu-target.c
index b6233f6bd1..a6a4f73abb 100644
--- a/cpu-target.c
+++ b/cpu-target.c
@@ -47,139 +47,10 @@
 
 //// --- Begin LibAFL code ---
 
-#include "exec/gdbstub.h"
-
-#include "libafl/exit.h"
-#include "libafl/hook.h"
-
-int gdb_write_register(CPUState *cpu, uint8_t *mem_buf, int reg);
-
-static __thread GByteArray *libafl_qemu_mem_buf = NULL;
-
-target_ulong libafl_page_from_addr(target_ulong addr);
-
-CPUState* libafl_qemu_get_cpu(int cpu_index);
-int libafl_qemu_num_cpus(void);
-CPUState* libafl_qemu_current_cpu(void);
-int libafl_qemu_cpu_index(CPUState*);
-
-int libafl_qemu_write_reg(CPUState* cpu, int reg, uint8_t* val);
-int libafl_qemu_read_reg(CPUState* cpu, int reg, uint8_t* val);
-int libafl_qemu_num_regs(CPUState* cpu);
-
 #ifndef CONFIG_USER_ONLY
-hwaddr libafl_qemu_current_paging_id(CPUState* cpu);
+#include "libafl/syx-snapshot/device-save.h"
 #endif
 
-void libafl_flush_jit(void);
-
-extern int libafl_restoring_devices;
-
-/*
-void* libafl_qemu_g2h(CPUState *cpu, target_ulong x);
-target_ulong libafl_qemu_h2g(CPUState *cpu, void* x);
-
-void* libafl_qemu_g2h(CPUState *cpu, target_ulong x)
-{
-    return g2h(cpu, x);
-}
-
-target_ulong libafl_qemu_h2g(CPUState *cpu, void* x)
-{
-    return h2g(cpu, x);
-}
-*/
-
-target_ulong libafl_page_from_addr(target_ulong addr) {
-    return addr & TARGET_PAGE_MASK;
-}
-
-CPUState* libafl_qemu_get_cpu(int cpu_index)
-{
-    CPUState *cpu;
-    CPU_FOREACH(cpu) {
-        if (cpu->cpu_index == cpu_index)
-            return cpu;
-    }
-    return NULL;
-}
-
-int libafl_qemu_num_cpus(void)
-{
-    CPUState *cpu;
-    int num = 0;
-    CPU_FOREACH(cpu) {
-        num++;
-    }
-    return num;
-}
-
-CPUState* libafl_qemu_current_cpu(void)
-{
-#ifndef CONFIG_USER_ONLY
-    if (current_cpu == NULL) {
-        return libafl_last_exit_cpu();
-    }
-#endif
-    return current_cpu;
-}
-
-int libafl_qemu_cpu_index(CPUState* cpu)
-{
-    if (cpu) return cpu->cpu_index;
-    return -1;
-}
-
-int libafl_qemu_write_reg(CPUState* cpu, int reg, uint8_t* val)
-{
-    return gdb_write_register(cpu, val, reg);
-}
-
-int libafl_qemu_read_reg(CPUState* cpu, int reg, uint8_t* val)
-{
-    int len;
-
-    if (libafl_qemu_mem_buf == NULL) {
-        libafl_qemu_mem_buf = g_byte_array_sized_new(64);
-    }
-
-    g_byte_array_set_size(libafl_qemu_mem_buf, 0);
-
-    len = gdb_read_register(cpu, libafl_qemu_mem_buf, reg);
-
-    if (len > 0) {
-        memcpy(val, libafl_qemu_mem_buf->data, len);
-    }
-
-    return len;
-}
-
-int libafl_qemu_num_regs(CPUState* cpu)
-{
-    CPUClass *cc = CPU_GET_CLASS(cpu);
-    return cc->gdb_num_core_regs;
-}
-
-#ifndef CONFIG_USER_ONLY
-hwaddr libafl_qemu_current_paging_id(CPUState* cpu)
-{
-    CPUClass* cc = CPU_GET_CLASS(cpu);
-    if (cc->sysemu_ops && cc->sysemu_ops->get_paging_id) {
-        return cc->sysemu_ops->get_paging_id(cpu);
-    } else {
-        return 0;
-    }
-}
-#endif
-
-void libafl_flush_jit(void)
-{
-    CPUState *cpu;
-    CPU_FOREACH(cpu) {
-        tb_flush(cpu);
-    }
-}
-
 //// --- End LibAFL code ---
 
 #ifndef CONFIG_USER_ONLY
@@ -203,7 +74,9 @@ static int cpu_common_post_load(void *opaque, int version_id)
 
     // flushing the TBs every restore makes it really slow
     // TODO handle writes to X code with specific calls to tb_invalidate_phys_addr
-    if (!libafl_restoring_devices) tb_flush(cpu);
+    if (!libafl_devices_is_restoring()) {
+        tb_flush(cpu);
+    }
 
 //// --- End LibAFL code ---
 
@@ -462,23 +335,6 @@ void list_cpus(void)
     cpu_list();
 }
 
-//// --- Begin LibAFL code ---
-#if defined(CONFIG_USER_ONLY)
-void libafl_breakpoint_invalidate(CPUState *cpu, target_ulong pc)
-{
-  mmap_lock();
-  tb_invalidate_phys_range(pc, pc + 1);
-  mmap_unlock();
-}
-#else
-void libafl_breakpoint_invalidate(CPUState *cpu, target_ulong pc)
-{
-  // TODO invalidate only the virtual pages related to the TB
-  tb_flush(cpu);
-}
-#endif
-//// --- End LibAFL code ---
-
 /* enable or disable single step mode. EXCP_DEBUG is returned by the
    CPU loop after each instruction */
 void cpu_single_step(CPUState *cpu, int enabled)
diff --git a/gdbstub/gdbstub.c b/gdbstub/gdbstub.c
index 0e10f53fad..2e6efe4d76 100644
--- a/gdbstub/gdbstub.c
+++ b/gdbstub/gdbstub.c
@@ -1648,30 +1648,6 @@ static void handle_query_thread_extra(GArray *params, void *user_ctx)
     gdb_put_strbuf();
 }
 
-//// --- Begin LibAFL code ---
-
-struct libafl_custom_gdb_cmd* libafl_qemu_gdb_cmds;
-
-void libafl_qemu_add_gdb_cmd(int (*callback)(void*, uint8_t*, size_t), void* data);
-void libafl_qemu_add_gdb_cmd(int (*callback)(void*, uint8_t*, size_t), void* data)
-{
-    struct libafl_custom_gdb_cmd* c = malloc(sizeof(struct libafl_custom_gdb_cmd));
-    c->callback = callback;
-    c->data = data;
-    c->next = libafl_qemu_gdb_cmds;
-    libafl_qemu_gdb_cmds = c;
-}
-
-void libafl_qemu_gdb_reply(const char* buf, size_t len);
-void libafl_qemu_gdb_reply(const char* buf, size_t len)
-{
-    g_autoptr(GString) hex_buf = g_string_new("O");
-    gdb_memtohex(hex_buf, (const uint8_t *) buf, len);
-    gdb_put_packet(hex_buf->str);
-}
-
-//// --- End LibAFL code ---
-
 static void handle_query_supported(GArray *params, void *user_ctx)
 {
     CPUClass *cc;
diff --git a/gdbstub/internals.h b/gdbstub/internals.h
index 79148ab542..32f9f63297 100644
--- a/gdbstub/internals.h
+++ b/gdbstub/internals.h
@@ -240,16 +240,4 @@ void gdb_breakpoint_remove_all(CPUState *cs);
 int gdb_target_memory_rw_debug(CPUState *cs, hwaddr addr,
                                uint8_t *buf, int len, bool is_write);
 
-//// --- Begin LibAFL code ---
-
-struct libafl_custom_gdb_cmd {
-    int (*callback)(void*, uint8_t*, size_t);
-    void* data;
-    struct libafl_custom_gdb_cmd* next;
-};
-
-extern struct libafl_custom_gdb_cmd* libafl_qemu_gdb_cmds;
-
-//// --- End LibAFL code ---
-
 #endif /* GDBSTUB_INTERNALS_H */
diff --git a/gdbstub/system.c b/gdbstub/system.c
index 0d126569b3..de0ae3fce6 100644
--- a/gdbstub/system.c
+++ b/gdbstub/system.c
@@ -30,6 +30,10 @@
 #include "trace.h"
 #include "internals.h"
 
+//// --- Begin LibAFL code ---
+#include "libafl/gdb.h"
+//// --- End LibAFL code ---
+
 /* System emulation specific state */
 typedef struct {
     CharBackend chr;
@@ -531,14 +535,7 @@ void gdb_handle_query_rcmd(GArray *params, void *ctx)
     
     //// --- Begin LibAFL code ---
 
-    struct libafl_custom_gdb_cmd** c = &libafl_qemu_gdb_cmds;
-    int recognized = 0;
-    while (*c) {
-        recognized |= (*c)->callback((*c)->data, gdbserver_state.mem_buf->data, gdbserver_state.mem_buf->len);
-        c = &(*c)->next;
-    }
-
-    if (recognized) {
+    if (libafl_qemu_gdb_exec()) {
         gdb_put_packet("OK");
         return;
     }
diff --git a/gdbstub/user-target.c b/gdbstub/user-target.c
index 6ef29ecbee..d8e0f01866 100644
--- a/gdbstub/user-target.c
+++ b/gdbstub/user-target.c
@@ -14,6 +14,11 @@
 #ifdef CONFIG_LINUX
 #include "linux-user/loader.h"
 #include "linux-user/qemu.h"
+
+//// --- Begin LibAFL code ---
+#include "libafl/gdb.h"
+//// --- End LibAFL code ---
+
 #endif
 
 /*
@@ -305,27 +310,17 @@ void gdb_handle_query_rcmd(GArray *params, void *user_ctx)
     g_assert(gdbserver_state.mem_buf->len == 0);
     len = len / 2;
     gdb_hextomem(gdbserver_state.mem_buf, get_param(params, 0)->data, len);
-    
-    //// --- Begin LibAFL code ---
-
-    struct libafl_custom_gdb_cmd** c = &libafl_qemu_gdb_cmds;
-    int recognized = 0;
-    while (*c) {
-        recognized |= (*c)->callback((*c)->data, gdbserver_state.mem_buf->data, gdbserver_state.mem_buf->len);
-        c = &(*c)->next;
-    }
 
-    if (recognized) {
+    if (libafl_qemu_gdb_exec()) {
         gdb_put_packet("OK");
     } else {
         gdb_put_packet("");
     }
 }
+#endif
 
 //// --- End LibAFL code ---
 
-#endif
-
 static const char *get_filename_param(GArray *params, int i)
 {
     const char *hex_filename = get_param(params, i)->data;
diff --git a/include/libafl/cpu.h b/include/libafl/cpu.h
new file mode 100644
index 0000000000..856a745593
--- /dev/null
+++ b/include/libafl/cpu.h
@@ -0,0 +1,31 @@
+#pragma once
+
+#include "qemu/osdep.h"
+
+#ifndef CONFIG_USER_ONLY
+#include "exec/memory.h"
+#include "qemu/rcu.h"
+#include "cpu.h"
+#endif
+
+#ifndef CONFIG_USER_ONLY
+uint8_t* libafl_paddr2host(CPUState* cpu, hwaddr addr, bool is_write);
+hwaddr libafl_qemu_current_paging_id(CPUState* cpu);
+#endif
+
+target_ulong libafl_page_from_addr(target_ulong addr);
+CPUState* libafl_qemu_get_cpu(int cpu_index);
+int libafl_qemu_num_cpus(void);
+CPUState* libafl_qemu_current_cpu(void);
+int libafl_qemu_cpu_index(CPUState*);
+int libafl_qemu_write_reg(CPUState* cpu, int reg, uint8_t* val);
+int libafl_qemu_read_reg(CPUState* cpu, int reg, uint8_t* val);
+int libafl_qemu_num_regs(CPUState* cpu);
+void libafl_flush_jit(void);
+void libafl_breakpoint_invalidate(CPUState* cpu, target_ulong pc);
+
+#ifdef CONFIG_USER_ONLY
+int libafl_qemu_main(void);
+int libafl_qemu_run(void);
+void libafl_set_qemu_env(CPUArchState* env);
+#endif
diff --git a/include/libafl/exit.h b/include/libafl/exit.h
index 55d6b8324e..839d26d9cd 100644
--- a/include/libafl/exit.h
+++ b/include/libafl/exit.h
@@ -12,9 +12,6 @@ struct libafl_breakpoint {
     struct libafl_breakpoint* next;
 };
 
-// in cpu-target.c
-void libafl_breakpoint_invalidate(CPUState* cpu, target_ulong pc);
-
 int libafl_qemu_set_breakpoint(target_ulong pc);
 int libafl_qemu_remove_breakpoint(target_ulong pc);
 void libafl_qemu_trigger_breakpoint(CPUState* cpu);
diff --git a/include/libafl/gdb.h b/include/libafl/gdb.h
new file mode 100644
index 0000000000..94e7debffb
--- /dev/null
+++ b/include/libafl/gdb.h
@@ -0,0 +1,14 @@
+#pragma once
+
+#include "qemu/osdep.h"
+
+struct libafl_custom_gdb_cmd {
+    bool (*callback)(void*, uint8_t*, size_t);
+    void* data;
+    struct libafl_custom_gdb_cmd* next;
+};
+
+void libafl_qemu_add_gdb_cmd(bool (*callback)(void*, uint8_t*, size_t),
+                             void* data);
+void libafl_qemu_gdb_reply(const uint8_t* buf, size_t len);
+bool libafl_qemu_gdb_exec(void);
diff --git a/include/libafl/qemu_snapshot.h b/include/libafl/qemu_snapshot.h
new file mode 100644
index 0000000000..b7f53a4247
--- /dev/null
+++ b/include/libafl/qemu_snapshot.h
@@ -0,0 +1,6 @@
+#pragma once
+
+#include "qemu/osdep.h"
+
+void libafl_save_qemu_snapshot(char* name, bool sync);
+void libafl_load_qemu_snapshot(char* name, bool sync);
diff --git a/include/libafl/syx-snapshot/device-save.h b/include/libafl/syx-snapshot/device-save.h
index c0ec400613..275cabad7a 100644
--- a/include/libafl/syx-snapshot/device-save.h
+++ b/include/libafl/syx-snapshot/device-save.h
@@ -24,3 +24,5 @@ void device_restore_all(DeviceSaveState* device_save_state);
 void device_free_all(DeviceSaveState* dss);
 
 char** device_list_all(void);
+
+bool libafl_devices_is_restoring(void);
diff --git a/include/libafl/user.h b/include/libafl/user.h
index b7b8f6a5bd..69eba3995f 100644
--- a/include/libafl/user.h
+++ b/include/libafl/user.h
@@ -2,6 +2,9 @@
 
 #include "qapi/error.h"
 #include "qemu/osdep.h"
+#include "qemu/interval-tree.h"
+
+#include "exec/cpu-defs.h"
 
 struct libafl_mapinfo {
     target_ulong start;
@@ -13,9 +16,17 @@ struct libafl_mapinfo {
     bool is_valid;
 };
 
+void libafl_dump_core_exec(int signal);
+
 void libafl_qemu_handle_crash(int host_sig, siginfo_t* info, void* puc);
 
 IntervalTreeNode* libafl_maps_first(IntervalTreeRoot* map_info);
 IntervalTreeNode* libafl_maps_next(IntervalTreeNode* pageflags_maps_node,
                                    IntervalTreeRoot* proc_maps_node,
                                    struct libafl_mapinfo* ret);
+
+uint64_t libafl_load_addr(void);
+struct image_info* libafl_get_image_info(void);
+
+uint64_t libafl_get_brk(void);
+uint64_t libafl_set_brk(uint64_t new_brk);
diff --git a/include/libafl/utils.h b/include/libafl/utils.h
index 9bcc1f2ea6..a4dd40f8c0 100644
--- a/include/libafl/utils.h
+++ b/include/libafl/utils.h
@@ -1,15 +1,3 @@
 #pragma once
 
-#include "qemu/osdep.h"
-
-#ifndef CONFIG_USER_ONLY
-#include "exec/memory.h"
-#include "qemu/rcu.h"
-#include "cpu.h"
-#endif
-
 uintptr_t libafl_qemu_host_page_size(void);
-
-#ifndef CONFIG_USER_ONLY
-uint8_t* libafl_paddr2host(CPUState* cpu, hwaddr addr, bool is_write);
-#endif
diff --git a/libafl/cpu.c b/libafl/cpu.c
new file mode 100644
index 0000000000..55b699c45e
--- /dev/null
+++ b/libafl/cpu.c
@@ -0,0 +1,160 @@
+#include "qemu/osdep.h"
+
+#ifdef CONFIG_USER_ONLY
+#include "qemu.h"
+#include "user-internals.h"
+#endif
+
+#include "exec/gdbstub.h"
+#include "exec/cpu-defs.h"
+#include "exec/tb-flush.h"
+#include "exec/exec-all.h"
+#include "hw/core/sysemu-cpu-ops.h"
+
+#include "libafl/cpu.h"
+
+#include "libafl/exit.h"
+#include "libafl/hook.h"
+
+int gdb_write_register(CPUState* cpu, uint8_t* mem_buf, int reg);
+
+static __thread GByteArray* libafl_qemu_mem_buf = NULL;
+
+#ifdef CONFIG_USER_ONLY
+static __thread CPUArchState* libafl_qemu_env;
+#endif
+
+#ifndef CONFIG_USER_ONLY
+uint8_t* libafl_paddr2host(CPUState* cpu, hwaddr addr, bool is_write)
+{
+    if (addr == -1) {
+        return NULL;
+    }
+
+    hwaddr xlat;
+    MemoryRegion* mr;
+    WITH_RCU_READ_LOCK_GUARD()
+    {
+        mr = address_space_translate(cpu->as, addr, &xlat, NULL, is_write,
+                                     MEMTXATTRS_UNSPECIFIED);
+    }
+
+    return qemu_map_ram_ptr(mr->ram_block, xlat);
+}
+
+hwaddr libafl_qemu_current_paging_id(CPUState* cpu)
+{
+    CPUClass* cc = CPU_GET_CLASS(cpu);
+    if (cc->sysemu_ops && cc->sysemu_ops->get_paging_id) {
+        return cc->sysemu_ops->get_paging_id(cpu);
+    } else {
+        return 0;
+    }
+}
+
+void libafl_breakpoint_invalidate(CPUState* cpu, target_ulong pc)
+{
+    // TODO invalidate only the virtual pages related to the TB
+    tb_flush(cpu);
+}
+#else
+void libafl_breakpoint_invalidate(CPUState* cpu, target_ulong pc)
+{
+    mmap_lock();
+    tb_invalidate_phys_range(pc, pc + 1);
+    mmap_unlock();
+}
+#endif
+
+target_ulong libafl_page_from_addr(target_ulong addr)
+{
+    return addr & TARGET_PAGE_MASK;
+}
+
+CPUState* libafl_qemu_get_cpu(int cpu_index)
+{
+    CPUState* cpu;
+    CPU_FOREACH(cpu)
+    {
+        if (cpu->cpu_index == cpu_index)
+            return cpu;
+    }
+    return NULL;
+}
+
+int libafl_qemu_num_cpus(void)
+{
+    CPUState* cpu;
+    int num = 0;
+    CPU_FOREACH(cpu) { num++; }
+    return num;
+}
+
+CPUState* libafl_qemu_current_cpu(void)
+{
+#ifndef CONFIG_USER_ONLY
+    if (current_cpu == NULL) {
+        return libafl_last_exit_cpu();
+    }
+#endif
+    return current_cpu;
+}
+
+int libafl_qemu_cpu_index(CPUState* cpu)
+{
+    if (cpu)
+        return cpu->cpu_index;
+    return -1;
+}
+
+int libafl_qemu_write_reg(CPUState* cpu, int reg, uint8_t* val)
+{
+    return gdb_write_register(cpu, val, reg);
+}
+
+int libafl_qemu_read_reg(CPUState* cpu, int reg, uint8_t* val)
+{
+    int len;
+
+    if (libafl_qemu_mem_buf == NULL) {
+        libafl_qemu_mem_buf = g_byte_array_sized_new(64);
+    }
+
+    g_byte_array_set_size(libafl_qemu_mem_buf, 0);
+
+    len = gdb_read_register(cpu, libafl_qemu_mem_buf, reg);
+
+    if (len > 0) {
+        memcpy(val, libafl_qemu_mem_buf->data, len);
+    }
+
+    return len;
+}
+
+int libafl_qemu_num_regs(CPUState* cpu)
+{
+    CPUClass* cc = CPU_GET_CLASS(cpu);
+    return cc->gdb_num_core_regs;
+}
+
+void libafl_flush_jit(void)
+{
+    CPUState* cpu;
+    CPU_FOREACH(cpu) { tb_flush(cpu); }
+}
+
+#ifdef CONFIG_USER_ONLY
+__attribute__((weak)) int libafl_qemu_main(void)
+{
+    libafl_qemu_run();
+    return 0;
+}
+
+int libafl_qemu_run(void)
+{
+    cpu_loop(libafl_qemu_env);
+    return 1;
+}
+
+void libafl_set_qemu_env(CPUArchState* env) { libafl_qemu_env = env; }
+#endif
diff --git a/libafl/exit.c b/libafl/exit.c
index 52a9534d6f..921800a20d 100644
--- a/libafl/exit.c
+++ b/libafl/exit.c
@@ -7,6 +7,7 @@
 #include "exec/translator.h"
 
 #include "cpu.h"
+#include "libafl/cpu.h"
 
 #ifdef CONFIG_USER_ONLY
 #define THREAD_MODIFIER __thread
diff --git a/libafl/gdb.c b/libafl/gdb.c
new file mode 100644
index 0000000000..9745287c46
--- /dev/null
+++ b/libafl/gdb.c
@@ -0,0 +1,35 @@
+#include "qemu/osdep.h"
+#include "libafl/gdb.h"
+#include "gdbstub/internals.h"
+
+static struct libafl_custom_gdb_cmd* libafl_qemu_gdb_cmds;
+
+void libafl_qemu_add_gdb_cmd(bool (*callback)(void*, uint8_t*, size_t),
+                             void* data)
+{
+    struct libafl_custom_gdb_cmd* c =
+        malloc(sizeof(struct libafl_custom_gdb_cmd));
+    c->callback = callback;
+    c->data = data;
+    c->next = libafl_qemu_gdb_cmds;
+    libafl_qemu_gdb_cmds = c;
+}
+
+void libafl_qemu_gdb_reply(const uint8_t* buf, size_t len)
+{
+    g_autoptr(GString) hex_buf = g_string_new("O");
+    gdb_memtohex(hex_buf, buf, len);
+    gdb_put_packet(hex_buf->str);
+}
+
+bool libafl_qemu_gdb_exec(void)
+{
+    struct libafl_custom_gdb_cmd** c = &libafl_qemu_gdb_cmds;
+    bool recognized = false;
+    while (*c) {
+        recognized |= (*c)->callback((*c)->data, gdbserver_state.mem_buf->data,
+                                     gdbserver_state.mem_buf->len);
+        c = &(*c)->next;
+    }
+    return recognized;
+}
diff --git a/libafl/hooks/tcg/instruction.c b/libafl/hooks/tcg/instruction.c
index 1e0fdbc650..21e6fa4cbe 100644
--- a/libafl/hooks/tcg/instruction.c
+++ b/libafl/hooks/tcg/instruction.c
@@ -1,5 +1,7 @@
 #include "libafl/hooks/tcg/instruction.h"
 
+#include "libafl/cpu.h"
+
 target_ulong libafl_gen_cur_pc;
 struct libafl_instruction_hook*
     libafl_qemu_instruction_hooks[LIBAFL_TABLES_SIZE];
diff --git a/libafl/hooks/thread.c b/libafl/hooks/thread.c
index bc5f19e668..b58ca8b57a 100644
--- a/libafl/hooks/thread.c
+++ b/libafl/hooks/thread.c
@@ -1,9 +1,8 @@
 #include "libafl/hooks/thread.h"
+#include "libafl/cpu.h"
 
 #include <linux/unistd.h>
 
-extern __thread CPUArchState* libafl_qemu_env;
-
 struct libafl_new_thread_hook* libafl_new_thread_hooks;
 size_t libafl_new_thread_hooks_num = 0;
 
@@ -27,7 +26,7 @@ size_t libafl_add_new_thread_hook(bool (*callback)(uint64_t data,
 
 bool libafl_hook_new_thread_run(CPUArchState* env)
 {
-    libafl_qemu_env = env;
+    libafl_set_qemu_env(env);
 
     if (libafl_new_thread_hooks) {
         bool continue_execution = true;
diff --git a/libafl/meson.build b/libafl/meson.build
index 9db973199e..3f4d2f5aad 100644
--- a/libafl/meson.build
+++ b/libafl/meson.build
@@ -1,8 +1,10 @@
 specific_ss.add(files(
+                    'cpu.c',
                     'exit.c',
                     'hook.c',
                     'jit.c',
                     'utils.c',
+                    'gdb.c',
 
                     # TCG-related hooks
                     'hooks/tcg/backdoor.c',
@@ -17,6 +19,7 @@ specific_ss.add(files(
                 ))
 
 specific_ss.add(when : 'CONFIG_SOFTMMU', if_true : [files(
+                                                        'qemu_snapshot.c',
                                                         'syx-snapshot/device-save.c',
                                                         'syx-snapshot/syx-snapshot.c',
                                                         'syx-snapshot/syx-cow-cache.c',
@@ -24,6 +27,7 @@ specific_ss.add(when : 'CONFIG_SOFTMMU', if_true : [files(
                                                     )])
 
 specific_ss.add(when : 'CONFIG_USER_ONLY', if_true : [files(
+                                                          'user.c',
                                                           'hooks/syscall.c',
                                                           'hooks/thread.c',
                                                     )])
diff --git a/libafl/qemu_snapshot.c b/libafl/qemu_snapshot.c
new file mode 100644
index 0000000000..b742465fa6
--- /dev/null
+++ b/libafl/qemu_snapshot.c
@@ -0,0 +1,89 @@
+#include "libafl/qemu_snapshot.h"
+
+#include "sysemu/runstate.h"
+#include "migration/snapshot.h"
+#include "qapi/error.h"
+#include "qemu/error-report.h"
+#include "qemu/main-loop.h"
+#include "hw/core/cpu.h"
+#include "sysemu/hw_accel.h"
+#include <stdlib.h>
+#include <string.h>
+
+static void save_snapshot_cb(void* opaque)
+{
+    char* name = (char*)opaque;
+    Error* err = NULL;
+    if (!save_snapshot(name, true, NULL, false, NULL, &err)) {
+        error_report_err(err);
+        error_report("Could not save snapshot");
+    }
+    free(opaque);
+}
+
+static void load_snapshot_cb(void* opaque)
+{
+    char* name = (char*)opaque;
+    Error* err = NULL;
+
+    int saved_vm_running = runstate_is_running();
+    vm_stop(RUN_STATE_RESTORE_VM);
+
+    bool loaded = load_snapshot(name, NULL, false, NULL, &err);
+
+    if (!loaded) {
+        error_report_err(err);
+        error_report("Could not load snapshot");
+    }
+    if (loaded && saved_vm_running) {
+        vm_start();
+    }
+    free(opaque);
+}
+
+void libafl_save_qemu_snapshot(char* name, bool sync)
+{
+    // use snapshots synchronously, use if main loop is not running
+    if (sync) {
+        // TODO: eliminate this code duplication
+        // by passing a heap-allocated buffer from rust to c,
+        // which c needs to free
+        Error* err = NULL;
+        if (!save_snapshot(name, true, NULL, false, NULL, &err)) {
+            error_report_err(err);
+            error_report("Could not save snapshot");
+        }
+        return;
+    }
+    char* name_buffer = malloc(strlen(name) + 1);
+    strcpy(name_buffer, name);
+    aio_bh_schedule_oneshot_full(qemu_get_aio_context(), save_snapshot_cb,
+                                 (void*)name_buffer, "save_snapshot");
+}
+
+void libafl_load_qemu_snapshot(char* name, bool sync)
+{
+    // use snapshots synchronously, use if main loop is not running
+    if (sync) {
+        // TODO: see libafl_save_qemu_snapshot
+        Error* err = NULL;
+
+        int saved_vm_running = runstate_is_running();
+        vm_stop(RUN_STATE_RESTORE_VM);
+
+        bool loaded = load_snapshot(name, NULL, false, NULL, &err);
+
+        if (!loaded) {
+            error_report_err(err);
+            error_report("Could not load snapshot");
+        }
+        if (loaded && saved_vm_running) {
+            vm_start();
+        }
+        return;
+    }
+    char* name_buffer = malloc(strlen(name) + 1);
+    strcpy(name_buffer, name);
+    aio_bh_schedule_oneshot_full(qemu_get_aio_context(), load_snapshot_cb,
+                                 (void*)name_buffer, "load_snapshot");
+}
diff --git a/libafl/syx-snapshot/device-save.c b/libafl/syx-snapshot/device-save.c
index 53140ec31d..1b12e231c0 100644
--- a/libafl/syx-snapshot/device-save.c
+++ b/libafl/syx-snapshot/device-save.c
@@ -11,12 +11,13 @@
 
 #include "migration/savevm.h"
 
-int libafl_restoring_devices;
-
 extern SaveState savevm_state;
-
 extern int vmstate_save(QEMUFile* f, SaveStateEntry* se, JSONWriter* vmdesc);
 
+static bool libafl_restoring_devices = false;
+
+bool libafl_devices_is_restoring(void) { return libafl_restoring_devices; }
+
 // iothread must be locked
 DeviceSaveState* device_save_all(void)
 {
@@ -101,8 +102,8 @@ void device_restore_all(DeviceSaveState* dss)
 
     QEMUFile* f = qemu_file_new_input(ioc);
 
-    int save_libafl_restoring_devices = libafl_restoring_devices;
-    libafl_restoring_devices = 1;
+    bool save_libafl_restoring_devices = libafl_restoring_devices;
+    libafl_restoring_devices = true;
 
     qemu_load_device_state(f);
 
diff --git a/libafl/user.c b/libafl/user.c
new file mode 100644
index 0000000000..e259361b97
--- /dev/null
+++ b/libafl/user.c
@@ -0,0 +1,37 @@
+#include "qemu/osdep.h"
+#include "qemu.h"
+#include "loader.h"
+
+#include "libafl/user.h"
+
+void (*libafl_dump_core_hook)(int host_sig) = NULL;
+static struct image_info libafl_image_info;
+
+extern abi_ulong target_brk, initial_target_brk;
+
+void host_signal_handler(int host_sig, siginfo_t* info, void* puc);
+
+void libafl_qemu_handle_crash(int host_sig, siginfo_t* info, void* puc)
+{
+    host_signal_handler(host_sig, info, puc);
+}
+
+void libafl_dump_core_exec(int signal)
+{
+    if (libafl_dump_core_hook) {
+        libafl_dump_core_hook(signal);
+    }
+}
+
+uint64_t libafl_load_addr(void) { return libafl_image_info.load_addr; }
+
+struct image_info* libafl_get_image_info(void) { return &libafl_image_info; }
+
+uint64_t libafl_get_brk(void) { return (uint64_t)target_brk; }
+
+uint64_t libafl_set_brk(uint64_t new_brk)
+{
+    uint64_t old_brk = (uint64_t)target_brk;
+    target_brk = (abi_ulong)new_brk;
+    return old_brk;
+}
diff --git a/libafl/utils.c b/libafl/utils.c
index de8b06aa66..427b0a44d5 100644
--- a/libafl/utils.c
+++ b/libafl/utils.c
@@ -5,24 +5,3 @@ uintptr_t libafl_qemu_host_page_size(void)
 {
     return qemu_real_host_page_size();
 }
-
-#ifndef CONFIG_USER_ONLY
-
-uint8_t* libafl_paddr2host(CPUState* cpu, hwaddr addr, bool is_write)
-{
-    if (addr == -1) {
-        return NULL;
-    }
-
-    hwaddr xlat;
-    MemoryRegion* mr;
-    WITH_RCU_READ_LOCK_GUARD()
-    {
-        mr = address_space_translate(cpu->as, addr, &xlat, NULL, is_write,
-                                     MEMTXATTRS_UNSPECIFIED);
-    }
-
-    return qemu_map_ram_ptr(mr->ram_block, xlat);
-}
-
-#endif
diff --git a/linux-user/main.c b/linux-user/main.c
index 31d14192c5..c46e7696b9 100644
--- a/linux-user/main.c
+++ b/linux-user/main.c
@@ -57,6 +57,11 @@
 #include "tcg/perf.h"
 #include "exec/page-vary.h"
 
+//// --- End LibAFL code ---
+#include "libafl/cpu.h"
+#include "libafl/user.h"
+//// --- Begin LibAFL code ---
+
 #ifdef CONFIG_SEMIHOSTING
 #include "semihosting/semihost.h"
 #endif
@@ -685,45 +690,22 @@ static int parse_args(int argc, char **argv)
 }
 
 //// --- Begin LibAFL code ---
-
-uint64_t libafl_load_addr(void);
-int libafl_qemu_main(void);
-int libafl_qemu_run(void);
-
-__thread CPUArchState *libafl_qemu_env;
-
-struct image_info libafl_image_info;
 struct linux_binprm bprm;
 
-uint64_t libafl_load_addr(void) {
-    return libafl_image_info.load_addr;
-}
-
-__attribute__((weak)) int libafl_qemu_main(void)
-{
-    libafl_qemu_run();
-    return 0;
-}
-
-int libafl_qemu_run(void)
-{
-    cpu_loop(libafl_qemu_env);
-    return 1;
-}
-
-//// --- End LibAFL code ---
-
 #ifdef AS_LIB
 int qemu_user_init(int argc, char **argv, char **envp);
 int qemu_user_init(int argc, char **argv, char **envp)
 #else
+//// --- End LibAFL code ---
 int main(int argc, char **argv, char **envp)
+//// --- Begin LibAFL code ---
 #endif
+//// --- End LibAFL code ---
 {
     struct target_pt_regs regs1, *regs = &regs1;
 //// --- Begin LibAFL code ---
     //struct image_info info1, *info = &info1;
-    struct image_info *info = &libafl_image_info;
+    struct image_info *info = libafl_get_image_info();
     // struct linux_binprm bprm;
 //// --- End LibAFL code ---
     TaskState *ts;
@@ -1076,7 +1058,7 @@ int main(int argc, char **argv, char **envp)
 
     //// --- Begin LibAFL code ---
 
-    libafl_qemu_env = env;
+    libafl_set_qemu_env(env);
 
 #ifndef AS_LIB
     return libafl_qemu_main();
diff --git a/linux-user/signal.c b/linux-user/signal.c
index d3df87dd59..15a2669e96 100644
--- a/linux-user/signal.c
+++ b/linux-user/signal.c
@@ -34,12 +34,21 @@
 #include "user/safe-syscall.h"
 #include "tcg/tcg.h"
 
+//// --- Begin LibAFL code ---
+
+#include "libafl/user.h"
+
+//// --- End LibAFL code ---
+
 /* target_siginfo_t must fit in gdbstub's siginfo save area. */
 QEMU_BUILD_BUG_ON(sizeof(target_siginfo_t) > MAX_SIGINFO_LENGTH);
 
 static struct target_sigaction sigact_table[TARGET_NSIG];
 
-static void host_signal_handler(int host_signum, siginfo_t *info,
+//// --- Begin LibAFL code ---
+/* static */
+//// --- End LibAFL code ---
+void host_signal_handler(int host_signum, siginfo_t *info,
                                 void *puc);
 
 /* Fallback addresses into sigtramp page. */
@@ -729,7 +738,6 @@ void die_with_signal(int host_sig)
 
 //// --- Begin LibAFL code ---
 
-void (*libafl_dump_core_hook)(int host_sig);
 
 //// --- End LibAFL code ---
 
@@ -770,8 +778,8 @@ void dump_core_and_abort(CPUArchState *env, int target_sig)
     
     //// --- Begin LibAFL code ---
 
-    if (libafl_dump_core_hook) libafl_dump_core_hook(host_sig);
-    
+    libafl_dump_core_exec(host_sig);
+
     // die_with_signal_nodfl(host_sig); // to trigger LibAFL sig handler
 
     //// --- End LibAFL code ---
@@ -890,9 +898,9 @@ void die_from_signal(siginfo_t *info)
                  sig, code, info->si_addr);
 
     //// --- Begin LibAFL code ---
-    
-    if (libafl_dump_core_hook) libafl_dump_core_hook(info->si_signo);
-    
+
+    libafl_dump_core_exec(info->si_signo);
+
     //// --- End LibAFL code ---
 
     die_with_signal(info->si_signo);
@@ -997,15 +1005,12 @@ static uintptr_t host_sigbus_handler(CPUState *cpu, siginfo_t *info,
                                        pc, guest_addr);
 } */
 
-#include "libafl/user.h"
-
-void libafl_qemu_handle_crash(int host_sig, siginfo_t *info, void *puc) {
-    host_signal_handler(host_sig, info, puc);
-}
-
 //// --- End LibAFL code ---
 
-static void host_signal_handler(int host_sig, siginfo_t *info, void *puc)
+//// --- Begin LibAFL code ---
+/* static */
+//// --- End LibAFL code ---
+void host_signal_handler(int host_sig, siginfo_t *info, void *puc)
 {
     CPUState *cpu = thread_cpu;
     CPUArchState *env = cpu_env(cpu);
diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index 82338df63c..a1479e77fe 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -805,7 +805,10 @@ static inline int host_to_target_sock_type(int host_type)
     return target_type;
 }
 
-static abi_ulong target_brk, initial_target_brk;
+//// --- Begin LibAFL code ---
+/* static */
+//// --- End LibAFL code ---
+abi_ulong target_brk, initial_target_brk;
 
 void target_set_brk(abi_ulong new_brk)
 {
@@ -813,23 +816,6 @@ void target_set_brk(abi_ulong new_brk)
     initial_target_brk = target_brk;
 }
 
-//// --- Begin LibAFL code ---
-
-uint64_t libafl_get_brk(void);
-uint64_t libafl_set_brk(uint64_t new_brk);
-
-uint64_t libafl_get_brk(void) {
-  return (uint64_t)target_brk;
-}
-
-uint64_t libafl_set_brk(uint64_t new_brk) {
-  uint64_t old_brk = (uint64_t)target_brk;
-  target_brk = (abi_ulong)new_brk;
-  return old_brk;
-}
-
-//// --- End LibAFL code ---
-
 /* do_brk() must return target values and target errnos. */
 abi_long do_brk(abi_ulong brk_val)
 {