[PATCH 00/18] Stop all qemu-cpu threads on a breakpoint

[Ilya Leoshkevich]

Hi,

On reporting a breakpoint in a non-non-stop mode, GDB remotes must stop
all threads. Currently qemu-user doesn't do that, breaking the
debugging session for at least two reasons: concurrent access to the
GDB socket, and an assertion within GDB [1].

This series fixes this by importing pause_all_vcpus() from qemu-system.
This in turn requires introducing BQL and a few stubs to qemu-user.

Best regards,
Ilya

[1] https://gitlab.com/qemu-project/qemu/-/issues/2465

Ilya Leoshkevich (18):
  gdbstub: Make gdb_get_char() static
  gdbstub: Move phy_memory_mode to GDBSystemState
  gdbstub: Move gdb_syscall_mode to GDBSyscallState
  gdbstub: Factor out gdb_try_stop()
  accel/tcg: Factor out cpu_exec_user()
  qemu-thread: Introduce QEMU_MUTEX_INITIALIZER
  qemu-thread: Introduce QEMU_COND_INITIALIZER
  replay: Add replay_mutex_{lock,unlock}() stubs for qemu-user
  qemu-timer: Provide qemu_clock_enable() stub for qemu-user
  cpu: Use BQL in qemu-user
  accel/tcg: Unify user implementations of qemu_cpu_kick()
  cpu: Track CPUs executing syscalls
  cpu: Implement cpu_thread_is_idle() for qemu-user
  cpu: Introduce cpu_is_paused()
  cpu: Set current_cpu early in qemu-user
  cpu: Allow pausing and resuming CPUs in qemu-user
  gdbstub: Pause all CPUs before sending stop replies
  tests/tcg: Stress test thread breakpoints

 accel/tcg/user-exec-stub.c                    |   4 -
 accel/tcg/user-exec.c                         |  55 ++++++
 bsd-user/aarch64/target_arch_cpu.h            |   6 +-
 bsd-user/arm/target_arch_cpu.h                |   5 +-
 bsd-user/freebsd/os-syscall.c                 |  10 +
 bsd-user/i386/target_arch_cpu.h               |   5 +-
 bsd-user/main.c                               |   8 +-
 bsd-user/x86_64/target_arch_cpu.h             |   5 +-
 cpu-common.c                                  | 179 ++++++++++++++++++
 gdbstub/gdbstub.c                             |  17 +-
 gdbstub/internals.h                           |   4 +-
 gdbstub/syscalls.c                            |  20 +-
 gdbstub/system.c                              |  18 +-
 gdbstub/user.c                                |  28 ++-
 include/exec/cpu-common.h                     |  15 ++
 include/exec/replay-core.h                    |  13 ++
 include/hw/core/cpu.h                         |   1 +
 include/qemu/thread-posix.h                   |   8 +
 include/qemu/thread-win32.h                   |   8 +
 include/sysemu/cpus.h                         |   6 -
 include/sysemu/replay.h                       |  13 --
 linux-user/aarch64/cpu_loop.c                 |   5 +-
 linux-user/alpha/cpu_loop.c                   |   5 +-
 linux-user/arm/cpu_loop.c                     |   5 +-
 linux-user/hexagon/cpu_loop.c                 |   5 +-
 linux-user/hppa/cpu_loop.c                    |   5 +-
 linux-user/i386/cpu_loop.c                    |   5 +-
 linux-user/loongarch64/cpu_loop.c             |   5 +-
 linux-user/m68k/cpu_loop.c                    |   5 +-
 linux-user/main.c                             |   9 +-
 linux-user/microblaze/cpu_loop.c              |   5 +-
 linux-user/mips/cpu_loop.c                    |   5 +-
 linux-user/openrisc/cpu_loop.c                |   5 +-
 linux-user/ppc/cpu_loop.c                     |   5 +-
 linux-user/riscv/cpu_loop.c                   |   5 +-
 linux-user/s390x/cpu_loop.c                   |   5 +-
 linux-user/sh4/cpu_loop.c                     |   5 +-
 linux-user/sparc/cpu_loop.c                   |   5 +-
 linux-user/syscall.c                          |  12 ++
 linux-user/xtensa/cpu_loop.c                  |   5 +-
 replay/stubs-system.c                         |   8 +
 stubs/meson.build                             |   8 +
 stubs/qemu-timer.c                            |   6 +
 stubs/replay-mutex.c                          |  10 +
 stubs/replay-tools.c                          |   8 -
 system/cpus.c                                 | 172 +----------------
 tests/tcg/multiarch/Makefile.target           |  13 +-
 .../gdbstub/test-thread-breakpoint-stress.py  |  28 +++
 .../tcg/multiarch/thread-breakpoint-stress.c  |  92 +++++++++
 49 files changed, 552 insertions(+), 327 deletions(-)
 create mode 100644 stubs/qemu-timer.c
 create mode 100644 stubs/replay-mutex.c
 create mode 100644 tests/tcg/multiarch/gdbstub/test-thread-breakpoint-stress.py
 create mode 100644 tests/tcg/multiarch/thread-breakpoint-stress.c

-- 
2.46.0