Merge tag 'pull-gdbstub-070323-3' of https://gitlab.com/stsquad/qemu into staging

gdbstub refactor:

  - split user and softmmu code
  - use cleaner headers for tb_flush, target_ulong
  - probe for gdb multiarch support at configure
  - make syscall handling target independent
  - add update guest debug of accel ops

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# gpg: Good signature from "Alex Bennée (Master Work Key) <alex.bennee@linaro.org>" [full]
# Primary key fingerprint: 6685 AE99 E751 67BC AFC8  DF35 FBD0 DB09 5A9E 2A44

* tag 'pull-gdbstub-070323-3' of https://gitlab.com/stsquad/qemu: (30 commits)
  gdbstub: move update guest debug to accel ops
  gdbstub: Build syscall.c once
  stubs: split semihosting_get_target from system only stubs
  gdbstub: Adjust gdb_do_syscall to only use uint32_t and uint64_t
  gdbstub: Remove gdb_do_syscallv
  gdbstub: split out softmmu/user specifics for syscall handling
  include: split target_long definition from cpu-defs
  testing: probe gdb for supported architectures ahead of time
  gdbstub: only compile gdbstub twice for whole build
  gdbstub: move syscall handling to new file
  gdbstub: move register helpers into standalone include
  gdbstub: don't use target_ulong while handling registers
  gdbstub: fix address type of gdb_set_cpu_pc
  gdbstub: specialise stub_can_reverse
  gdbstub: introduce gdb_get_max_cpus
  gdbstub: specialise target_memory_rw_debug
  gdbstub: specialise handle_query_attached
  gdbstub: abstract target specific details from gdb_put_packet_binary
  gdbstub: rationalise signal mapping in softmmu
  gdbstub: move chunks of user code into own files
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

9 files changed, 329 insertions, 227 deletions

diff --git a/include/exec/cpu-defs.h b/include/exec/cpu-defs.h
index be920d4208..cd8aa177cc 100644
--- a/include/exec/cpu-defs.h
+++ b/include/exec/cpu-defs.h
@@ -55,24 +55,7 @@
 # endif
 #endif
 
-#define TARGET_LONG_SIZE (TARGET_LONG_BITS / 8)
-
-/* target_ulong is the type of a virtual address */
-#if TARGET_LONG_SIZE == 4
-typedef int32_t target_long;
-typedef uint32_t target_ulong;
-#define TARGET_FMT_lx "%08x"
-#define TARGET_FMT_ld "%d"
-#define TARGET_FMT_lu "%u"
-#elif TARGET_LONG_SIZE == 8
-typedef int64_t target_long;
-typedef uint64_t target_ulong;
-#define TARGET_FMT_lx "%016" PRIx64
-#define TARGET_FMT_ld "%" PRId64
-#define TARGET_FMT_lu "%" PRIu64
-#else
-#error TARGET_LONG_SIZE undefined
-#endif
+#include "exec/target_long.h"
 
 #if !defined(CONFIG_USER_ONLY) && defined(CONFIG_TCG)
 
diff --git a/include/exec/exec-all.h b/include/exec/exec-all.h
index e09254333d..ad9eb6067b 100644
--- a/include/exec/exec-all.h
+++ b/include/exec/exec-all.h
@@ -677,7 +677,6 @@ void tb_invalidate_phys_addr(target_ulong addr);
 #else
 void tb_invalidate_phys_addr(AddressSpace *as, hwaddr addr, MemTxAttrs attrs);
 #endif
-void tb_flush(CPUState *cpu);
 void tb_phys_invalidate(TranslationBlock *tb, tb_page_addr_t page_addr);
 void tb_invalidate_phys_range(tb_page_addr_t start, tb_page_addr_t end);
 void tb_set_jmp_target(TranslationBlock *tb, int n, uintptr_t addr);
diff --git a/include/exec/gdbstub.h b/include/exec/gdbstub.h
index f667014888..7d743fe1e9 100644
--- a/include/exec/gdbstub.h
+++ b/include/exec/gdbstub.h
@@ -10,122 +10,7 @@
 #define GDB_WATCHPOINT_READ      3
 #define GDB_WATCHPOINT_ACCESS    4
 
-/* For gdb file i/o remote protocol open flags. */
-#define GDB_O_RDONLY  0
-#define GDB_O_WRONLY  1
-#define GDB_O_RDWR    2
-#define GDB_O_APPEND  8
-#define GDB_O_CREAT   0x200
-#define GDB_O_TRUNC   0x400
-#define GDB_O_EXCL    0x800
 
-/* For gdb file i/o remote protocol errno values */
-#define GDB_EPERM           1
-#define GDB_ENOENT          2
-#define GDB_EINTR           4
-#define GDB_EBADF           9
-#define GDB_EACCES         13
-#define GDB_EFAULT         14
-#define GDB_EBUSY          16
-#define GDB_EEXIST         17
-#define GDB_ENODEV         19
-#define GDB_ENOTDIR        20
-#define GDB_EISDIR         21
-#define GDB_EINVAL         22
-#define GDB_ENFILE         23
-#define GDB_EMFILE         24
-#define GDB_EFBIG          27
-#define GDB_ENOSPC         28
-#define GDB_ESPIPE         29
-#define GDB_EROFS          30
-#define GDB_ENAMETOOLONG   91
-#define GDB_EUNKNOWN       9999
-
-/* For gdb file i/o remote protocol lseek whence. */
-#define GDB_SEEK_SET  0
-#define GDB_SEEK_CUR  1
-#define GDB_SEEK_END  2
-
-/* For gdb file i/o stat/fstat. */
-typedef uint32_t gdb_mode_t;
-typedef uint32_t gdb_time_t;
-
-struct gdb_stat {
-  uint32_t    gdb_st_dev;     /* device */
-  uint32_t    gdb_st_ino;     /* inode */
-  gdb_mode_t  gdb_st_mode;    /* protection */
-  uint32_t    gdb_st_nlink;   /* number of hard links */
-  uint32_t    gdb_st_uid;     /* user ID of owner */
-  uint32_t    gdb_st_gid;     /* group ID of owner */
-  uint32_t    gdb_st_rdev;    /* device type (if inode device) */
-  uint64_t    gdb_st_size;    /* total size, in bytes */
-  uint64_t    gdb_st_blksize; /* blocksize for filesystem I/O */
-  uint64_t    gdb_st_blocks;  /* number of blocks allocated */
-  gdb_time_t  gdb_st_atime;   /* time of last access */
-  gdb_time_t  gdb_st_mtime;   /* time of last modification */
-  gdb_time_t  gdb_st_ctime;   /* time of last change */
-} QEMU_PACKED;
-
-struct gdb_timeval {
-  gdb_time_t tv_sec;  /* second */
-  uint64_t tv_usec;   /* microsecond */
-} QEMU_PACKED;
-
-#ifdef NEED_CPU_H
-#include "cpu.h"
-
-typedef void (*gdb_syscall_complete_cb)(CPUState *cpu, uint64_t ret, int err);
-
-/**
- * gdb_do_syscall:
- * @cb: function to call when the system call has completed
- * @fmt: gdb syscall format string
- * ...: list of arguments to interpolate into @fmt
- *
- * Send a GDB syscall request. This function will return immediately;
- * the callback function will be called later when the remote system
- * call has completed.
- *
- * @fmt should be in the 'call-id,parameter,parameter...' format documented
- * for the F request packet in the GDB remote protocol. A limited set of
- * printf-style format specifiers is supported:
- *   %x  - target_ulong argument printed in hex
- *   %lx - 64-bit argument printed in hex
- *   %s  - string pointer (target_ulong) and length (int) pair
- */
-void gdb_do_syscall(gdb_syscall_complete_cb cb, const char *fmt, ...);
-/**
- * gdb_do_syscallv:
- * @cb: function to call when the system call has completed
- * @fmt: gdb syscall format string
- * @va: arguments to interpolate into @fmt
- *
- * As gdb_do_syscall, but taking a va_list rather than a variable
- * argument list.
- */
-void gdb_do_syscallv(gdb_syscall_complete_cb cb, const char *fmt, va_list va);
-int use_gdb_syscalls(void);
-
-#ifdef CONFIG_USER_ONLY
-/**
- * gdb_handlesig: yield control to gdb
- * @cpu: CPU
- * @sig: if non-zero, the signal number which caused us to stop
- *
- * This function yields control to gdb, when a user-mode-only target
- * needs to stop execution. If @sig is non-zero, then we will send a
- * stop packet to tell gdb that we have stopped because of this signal.
- *
- * This function will block (handling protocol requests from gdb)
- * until gdb tells us to continue target execution. When it does
- * return, the return value is a signal to deliver to the target,
- * or 0 if no signal should be delivered, ie the signal that caused
- * us to stop should be ignored.
- */
-int gdb_handlesig(CPUState *, int);
-void gdb_signalled(CPUArchState *, int);
-void gdbserver_fork(CPUState *);
-#endif
 /* Get or set a register.  Returns the size of the register.  */
 typedef int (*gdb_get_reg_cb)(CPUArchState *env, GByteArray *buf, int reg);
 typedef int (*gdb_set_reg_cb)(CPUArchState *env, uint8_t *buf, int reg);
@@ -133,89 +18,6 @@ void gdb_register_coprocessor(CPUState *cpu,
                               gdb_get_reg_cb get_reg, gdb_set_reg_cb set_reg,
                               int num_regs, const char *xml, int g_pos);
 
-/*
- * The GDB remote protocol transfers values in target byte order. As
- * the gdbstub may be batching up several register values we always
- * append to the array.
- */
-
-static inline int gdb_get_reg8(GByteArray *buf, uint8_t val)
-{
-    g_byte_array_append(buf, &val, 1);
-    return 1;
-}
-
-static inline int gdb_get_reg16(GByteArray *buf, uint16_t val)
-{
-    uint16_t to_word = tswap16(val);
-    g_byte_array_append(buf, (uint8_t *) &to_word, 2);
-    return 2;
-}
-
-static inline int gdb_get_reg32(GByteArray *buf, uint32_t val)
-{
-    uint32_t to_long = tswap32(val);
-    g_byte_array_append(buf, (uint8_t *) &to_long, 4);
-    return 4;
-}
-
-static inline int gdb_get_reg64(GByteArray *buf, uint64_t val)
-{
-    uint64_t to_quad = tswap64(val);
-    g_byte_array_append(buf, (uint8_t *) &to_quad, 8);
-    return 8;
-}
-
-static inline int gdb_get_reg128(GByteArray *buf, uint64_t val_hi,
-                                 uint64_t val_lo)
-{
-    uint64_t to_quad;
-#if TARGET_BIG_ENDIAN
-    to_quad = tswap64(val_hi);
-    g_byte_array_append(buf, (uint8_t *) &to_quad, 8);
-    to_quad = tswap64(val_lo);
-    g_byte_array_append(buf, (uint8_t *) &to_quad, 8);
-#else
-    to_quad = tswap64(val_lo);
-    g_byte_array_append(buf, (uint8_t *) &to_quad, 8);
-    to_quad = tswap64(val_hi);
-    g_byte_array_append(buf, (uint8_t *) &to_quad, 8);
-#endif
-    return 16;
-}
-
-static inline int gdb_get_zeroes(GByteArray *array, size_t len)
-{
-    guint oldlen = array->len;
-    g_byte_array_set_size(array, oldlen + len);
-    memset(array->data + oldlen, 0, len);
-
-    return len;
-}
-
-/**
- * gdb_get_reg_ptr: get pointer to start of last element
- * @len: length of element
- *
- * This is a helper function to extract the pointer to the last
- * element for additional processing. Some front-ends do additional
- * dynamic swapping of the elements based on CPU state.
- */
-static inline uint8_t * gdb_get_reg_ptr(GByteArray *buf, int len)
-{
-    return buf->data + buf->len - len;
-}
-
-#if TARGET_LONG_BITS == 64
-#define gdb_get_regl(buf, val) gdb_get_reg64(buf, val)
-#define ldtul_p(addr) ldq_p(addr)
-#else
-#define gdb_get_regl(buf, val) gdb_get_reg32(buf, val)
-#define ldtul_p(addr) ldl_p(addr)
-#endif
-
-#endif /* NEED_CPU_H */
-
 /**
  * gdbserver_start: start the gdb server
  * @port_or_device: connection spec for gdb
@@ -226,16 +28,6 @@ static inline uint8_t * gdb_get_reg_ptr(GByteArray *buf, int len)
  */
 int gdbserver_start(const char *port_or_device);
 
-/**
- * gdb_exit: exit gdb session, reporting inferior status
- * @code: exit code reported
- *
- * This closes the session and sends a final packet to GDB reporting
- * the exit status of the program. It also cleans up any connections
- * detritus before returning.
- */
-void gdb_exit(int code);
-
 void gdb_set_stop_cpu(CPUState *cpu);
 
 /**
diff --git a/include/exec/target_long.h b/include/exec/target_long.h
new file mode 100644
index 0000000000..93c9472971
--- /dev/null
+++ b/include/exec/target_long.h
@@ -0,0 +1,42 @@
+/*
+ * Target Long Definitions
+ *
+ * Copyright (c) 2003 Fabrice Bellard
+ * Copyright (c) 2023 Linaro Ltd
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#ifndef _TARGET_LONG_H_
+#define _TARGET_LONG_H_
+
+/*
+ * Usually this should only be included via cpu-defs.h however for
+ * certain cases where we want to build only two versions of a binary
+ * object we can include directly. However the build-system must
+ * ensure TARGET_LONG_BITS is defined directly.
+ */
+#ifndef TARGET_LONG_BITS
+#error TARGET_LONG_BITS not defined
+#endif
+
+#define TARGET_LONG_SIZE (TARGET_LONG_BITS / 8)
+
+/* target_ulong is the type of a virtual address */
+#if TARGET_LONG_SIZE == 4
+typedef int32_t target_long;
+typedef uint32_t target_ulong;
+#define TARGET_FMT_lx "%08x"
+#define TARGET_FMT_ld "%d"
+#define TARGET_FMT_lu "%u"
+#elif TARGET_LONG_SIZE == 8
+typedef int64_t target_long;
+typedef uint64_t target_ulong;
+#define TARGET_FMT_lx "%016" PRIx64
+#define TARGET_FMT_ld "%" PRId64
+#define TARGET_FMT_lu "%" PRIu64
+#else
+#error TARGET_LONG_SIZE undefined
+#endif
+
+#endif /* _TARGET_LONG_H_ */
diff --git a/include/exec/tb-flush.h b/include/exec/tb-flush.h
new file mode 100644
index 0000000000..d92d06565b
--- /dev/null
+++ b/include/exec/tb-flush.h
@@ -0,0 +1,26 @@
+/*
+ * tb-flush prototype for use by the rest of the system.
+ *
+ * Copyright (c) 2022 Linaro Ltd
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+#ifndef _TB_FLUSH_H_
+#define _TB_FLUSH_H_
+
+/**
+ * tb_flush() - flush all translation blocks
+ * @cs: CPUState (must be valid, but treated as anonymous pointer)
+ *
+ * Used to flush all the translation blocks in the system. Sometimes
+ * it is simpler to flush everything than work out which individual
+ * translations are now invalid and ensure they are not called
+ * anymore.
+ *
+ * tb_flush() takes care of running the flush in an exclusive context
+ * if it is not already running in one. This means no guest code will
+ * run until this complete.
+ */
+void tb_flush(CPUState *cs);
+
+#endif /* _TB_FLUSH_H_ */
diff --git a/include/gdbstub/helpers.h b/include/gdbstub/helpers.h
new file mode 100644
index 0000000000..c573aef2dc
--- /dev/null
+++ b/include/gdbstub/helpers.h
@@ -0,0 +1,103 @@
+/*
+ * gdbstub helpers
+ *
+ * These are all used by the various frontends and have to be host
+ * aware to ensure things are store in target order.
+ *
+ * Copyright (c) 2022 Linaro Ltd
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#ifndef _GDBSTUB_HELPERS_H_
+#define _GDBSTUB_HELPERS_H_
+
+#ifdef NEED_CPU_H
+#include "cpu.h"
+
+/*
+ * The GDB remote protocol transfers values in target byte order. As
+ * the gdbstub may be batching up several register values we always
+ * append to the array.
+ */
+
+static inline int gdb_get_reg8(GByteArray *buf, uint8_t val)
+{
+    g_byte_array_append(buf, &val, 1);
+    return 1;
+}
+
+static inline int gdb_get_reg16(GByteArray *buf, uint16_t val)
+{
+    uint16_t to_word = tswap16(val);
+    g_byte_array_append(buf, (uint8_t *) &to_word, 2);
+    return 2;
+}
+
+static inline int gdb_get_reg32(GByteArray *buf, uint32_t val)
+{
+    uint32_t to_long = tswap32(val);
+    g_byte_array_append(buf, (uint8_t *) &to_long, 4);
+    return 4;
+}
+
+static inline int gdb_get_reg64(GByteArray *buf, uint64_t val)
+{
+    uint64_t to_quad = tswap64(val);
+    g_byte_array_append(buf, (uint8_t *) &to_quad, 8);
+    return 8;
+}
+
+static inline int gdb_get_reg128(GByteArray *buf, uint64_t val_hi,
+                                 uint64_t val_lo)
+{
+    uint64_t to_quad;
+#if TARGET_BIG_ENDIAN
+    to_quad = tswap64(val_hi);
+    g_byte_array_append(buf, (uint8_t *) &to_quad, 8);
+    to_quad = tswap64(val_lo);
+    g_byte_array_append(buf, (uint8_t *) &to_quad, 8);
+#else
+    to_quad = tswap64(val_lo);
+    g_byte_array_append(buf, (uint8_t *) &to_quad, 8);
+    to_quad = tswap64(val_hi);
+    g_byte_array_append(buf, (uint8_t *) &to_quad, 8);
+#endif
+    return 16;
+}
+
+static inline int gdb_get_zeroes(GByteArray *array, size_t len)
+{
+    guint oldlen = array->len;
+    g_byte_array_set_size(array, oldlen + len);
+    memset(array->data + oldlen, 0, len);
+
+    return len;
+}
+
+/**
+ * gdb_get_reg_ptr: get pointer to start of last element
+ * @len: length of element
+ *
+ * This is a helper function to extract the pointer to the last
+ * element for additional processing. Some front-ends do additional
+ * dynamic swapping of the elements based on CPU state.
+ */
+static inline uint8_t *gdb_get_reg_ptr(GByteArray *buf, int len)
+{
+    return buf->data + buf->len - len;
+}
+
+#if TARGET_LONG_BITS == 64
+#define gdb_get_regl(buf, val) gdb_get_reg64(buf, val)
+#define ldtul_p(addr) ldq_p(addr)
+#else
+#define gdb_get_regl(buf, val) gdb_get_reg32(buf, val)
+#define ldtul_p(addr) ldl_p(addr)
+#endif
+
+#else
+#error "gdbstub helpers should only be included by target specific code"
+#endif
+
+#endif /* _GDBSTUB_HELPERS_H_ */
diff --git a/include/gdbstub/syscalls.h b/include/gdbstub/syscalls.h
new file mode 100644
index 0000000000..243eaf8ce4
--- /dev/null
+++ b/include/gdbstub/syscalls.h
@@ -0,0 +1,113 @@
+/*
+ * GDB Syscall support
+ *
+ * Copyright (c) 2023 Linaro Ltd
+ *
+ * SPDX-License-Identifier: LGPL-2.0+
+ */
+
+#ifndef _SYSCALLS_H_
+#define _SYSCALLS_H_
+
+/* For gdb file i/o remote protocol open flags. */
+#define GDB_O_RDONLY  0
+#define GDB_O_WRONLY  1
+#define GDB_O_RDWR    2
+#define GDB_O_APPEND  8
+#define GDB_O_CREAT   0x200
+#define GDB_O_TRUNC   0x400
+#define GDB_O_EXCL    0x800
+
+/* For gdb file i/o remote protocol errno values */
+#define GDB_EPERM           1
+#define GDB_ENOENT          2
+#define GDB_EINTR           4
+#define GDB_EBADF           9
+#define GDB_EACCES         13
+#define GDB_EFAULT         14
+#define GDB_EBUSY          16
+#define GDB_EEXIST         17
+#define GDB_ENODEV         19
+#define GDB_ENOTDIR        20
+#define GDB_EISDIR         21
+#define GDB_EINVAL         22
+#define GDB_ENFILE         23
+#define GDB_EMFILE         24
+#define GDB_EFBIG          27
+#define GDB_ENOSPC         28
+#define GDB_ESPIPE         29
+#define GDB_EROFS          30
+#define GDB_ENAMETOOLONG   91
+#define GDB_EUNKNOWN       9999
+
+/* For gdb file i/o remote protocol lseek whence. */
+#define GDB_SEEK_SET  0
+#define GDB_SEEK_CUR  1
+#define GDB_SEEK_END  2
+
+/* For gdb file i/o stat/fstat. */
+typedef uint32_t gdb_mode_t;
+typedef uint32_t gdb_time_t;
+
+struct gdb_stat {
+  uint32_t    gdb_st_dev;     /* device */
+  uint32_t    gdb_st_ino;     /* inode */
+  gdb_mode_t  gdb_st_mode;    /* protection */
+  uint32_t    gdb_st_nlink;   /* number of hard links */
+  uint32_t    gdb_st_uid;     /* user ID of owner */
+  uint32_t    gdb_st_gid;     /* group ID of owner */
+  uint32_t    gdb_st_rdev;    /* device type (if inode device) */
+  uint64_t    gdb_st_size;    /* total size, in bytes */
+  uint64_t    gdb_st_blksize; /* blocksize for filesystem I/O */
+  uint64_t    gdb_st_blocks;  /* number of blocks allocated */
+  gdb_time_t  gdb_st_atime;   /* time of last access */
+  gdb_time_t  gdb_st_mtime;   /* time of last modification */
+  gdb_time_t  gdb_st_ctime;   /* time of last change */
+} QEMU_PACKED;
+
+struct gdb_timeval {
+  gdb_time_t tv_sec;  /* second */
+  uint64_t tv_usec;   /* microsecond */
+} QEMU_PACKED;
+
+typedef void (*gdb_syscall_complete_cb)(CPUState *cpu, uint64_t ret, int err);
+
+/**
+ * gdb_do_syscall:
+ * @cb: function to call when the system call has completed
+ * @fmt: gdb syscall format string
+ * ...: list of arguments to interpolate into @fmt
+ *
+ * Send a GDB syscall request. This function will return immediately;
+ * the callback function will be called later when the remote system
+ * call has completed.
+ *
+ * @fmt should be in the 'call-id,parameter,parameter...' format documented
+ * for the F request packet in the GDB remote protocol. A limited set of
+ * printf-style format specifiers is supported:
+ *   %x  - target_ulong argument printed in hex
+ *   %lx - 64-bit argument printed in hex
+ *   %s  - string pointer (target_ulong) and length (int) pair
+ */
+void gdb_do_syscall(gdb_syscall_complete_cb cb, const char *fmt, ...);
+
+/**
+ * use_gdb_syscalls() - report if GDB should be used for syscalls
+ *
+ * This is mostly driven by the semihosting mode the user configures
+ * but assuming GDB is allowed by that we report true if GDB is
+ * connected to the stub.
+ */
+int use_gdb_syscalls(void);
+
+/**
+ * gdb_exit: exit gdb session, reporting inferior status
+ * @code: exit code reported
+ *
+ * This closes the session and sends a final packet to GDB reporting
+ * the exit status of the program. It also cleans up any connections
+ * detritus before returning.
+ */
+void gdb_exit(int code);
+
+#endif /* _SYSCALLS_H_ */
diff --git a/include/gdbstub/user.h b/include/gdbstub/user.h
new file mode 100644
index 0000000000..d392e510c5
--- /dev/null
+++ b/include/gdbstub/user.h
@@ -0,0 +1,43 @@
+/*
+ * gdbstub user-mode only APIs
+ *
+ * Copyright (c) 2022 Linaro Ltd
+ *
+ * SPDX-License-Identifier: LGPL-2.0+
+ */
+
+#ifndef GDBSTUB_USER_H
+#define GDBSTUB_USER_H
+
+/**
+ * gdb_handlesig() - yield control to gdb
+ * @cpu: CPU
+ * @sig: if non-zero, the signal number which caused us to stop
+ *
+ * This function yields control to gdb, when a user-mode-only target
+ * needs to stop execution. If @sig is non-zero, then we will send a
+ * stop packet to tell gdb that we have stopped because of this signal.
+ *
+ * This function will block (handling protocol requests from gdb)
+ * until gdb tells us to continue target execution. When it does
+ * return, the return value is a signal to deliver to the target,
+ * or 0 if no signal should be delivered, ie the signal that caused
+ * us to stop should be ignored.
+ */
+int gdb_handlesig(CPUState *, int);
+
+/**
+ * gdb_signalled() - inform remote gdb of sig exit
+ * @as: current CPUArchState
+ * @sig: signal number
+ */
+void gdb_signalled(CPUArchState *as, int sig);
+
+/**
+ * gdbserver_fork() - disable gdb stub for child processes.
+ * @cs: CPU
+ */
+void gdbserver_fork(CPUState *cs);
+
+
+#endif /* GDBSTUB_USER_H */
diff --git a/include/sysemu/accel-ops.h b/include/sysemu/accel-ops.h
index 30690c71bd..3c1fab4b1e 100644
--- a/include/sysemu/accel-ops.h
+++ b/include/sysemu/accel-ops.h
@@ -48,6 +48,7 @@ struct AccelOpsClass {
 
     /* gdbstub hooks */
     bool (*supports_guest_debug)(void);
+    int (*update_guest_debug)(CPUState *cpu);
     int (*insert_breakpoint)(CPUState *cpu, int type, vaddr addr, vaddr len);
     int (*remove_breakpoint)(CPUState *cpu, int type, vaddr addr, vaddr len);
     void (*remove_all_breakpoints)(CPUState *cpu);