Pavel Dovgalyuk <pavel.dovgal...@ispras.ru> writes:
> From: Pavel Dovgalyuk <pavel.dovga...@ispras.ru>
>
> GDB remote protocol supports two reverse debugging commands:
> reverse step and reverse continue.
> This patch adds support of the first one to the gdbstub.
> Reverse step is intended to step one instruction in the backwards
> direction. This is not possible in regular execution.
> But replayed execution is deterministic, therefore we can load one of
> the prior snapshots and proceed to the desired step. It is equivalent
> to stepping one instruction back.
> There should be at least one snapshot preceding the debugged part of
> the replay log.
>
> Signed-off-by: Pavel Dovgalyuk <pavel.dovgal...@ispras.ru>
> ---
> 0 files changed
>
> diff --git a/accel/tcg/translator.c b/accel/tcg/translator.c
> index 603d17ff83..fb1e19c585 100644
> --- a/accel/tcg/translator.c
> +++ b/accel/tcg/translator.c
> @@ -17,6 +17,7 @@
> #include "exec/log.h"
> #include "exec/translator.h"
> #include "exec/plugin-gen.h"
> +#include "sysemu/replay.h"
>
> /* Pairs with tcg_clear_temp_count.
> To be called by #TranslatorOps.{translate_insn,tb_stop} if
> diff --git a/cpus.c b/cpus.c
> index 41d1c5099f..35381ea941 100644
> --- a/cpus.c
> +++ b/cpus.c
> @@ -1100,9 +1100,17 @@ static bool cpu_can_run(CPUState *cpu)
>
> static void cpu_handle_guest_debug(CPUState *cpu)
> {
> - gdb_set_stop_cpu(cpu);
> - qemu_system_debug_request();
> - cpu->stopped = true;
> + if (!replay_running_debug()) {
> + gdb_set_stop_cpu(cpu);
> + qemu_system_debug_request();
> + cpu->stopped = true;
> + } else {
> + if (!cpu->singlestep_enabled) {
> + cpu_single_step(cpu, SSTEP_ENABLE);
> + } else {
> + cpu_single_step(cpu, 0);
> + }
> + }
This no longer applies cleanly.
--
Alex Bennée
