When QEMU watchpoint matches, that is not definitely an architectural watchpoint match yet. If it is a stop-before-access watchpoint then that is hardly possible to ignore it after throwing a TCG exception.
A special callback is introduced to check for architectural watchpoint match before raising a TCG exception. Signed-off-by: Sergey Fedorov <[email protected]> --- exec.c | 5 +++++ include/qom/cpu.h | 3 +++ qom/cpu.c | 9 +++++++++ 3 files changed, 17 insertions(+) diff --git a/exec.c b/exec.c index 54cd70a..64ed543 100644 --- a/exec.c +++ b/exec.c @@ -1921,6 +1921,7 @@ static const MemoryRegionOps notdirty_mem_ops = { static void check_watchpoint(int offset, int len, MemTxAttrs attrs, int flags) { CPUState *cpu = current_cpu; + CPUClass *cc = CPU_GET_CLASS(cpu); CPUArchState *env = cpu->env_ptr; target_ulong pc, cs_base; target_ulong vaddr; @@ -1947,6 +1948,10 @@ static void check_watchpoint(int offset, int len, MemTxAttrs attrs, int flags) wp->hitattrs = attrs; if (!cpu->watchpoint_hit) { cpu->watchpoint_hit = wp; + if (wp->flags & BP_CPU && !cc->debug_check_watchpoint(cpu)) { + cpu->watchpoint_hit = NULL; + continue; + } tb_check_watchpoint(cpu); if (wp->flags & BP_STOP_BEFORE_ACCESS) { cpu->exception_index = EXCP_DEBUG; diff --git a/include/qom/cpu.h b/include/qom/cpu.h index 39712ab..4e0a1b9 100644 --- a/include/qom/cpu.h +++ b/include/qom/cpu.h @@ -101,6 +101,8 @@ struct TranslationBlock; * @get_phys_page_debug: Callback for obtaining a physical address. * @gdb_read_register: Callback for letting GDB read a register. * @gdb_write_register: Callback for letting GDB write a register. + * @debug_check_watchpoint: Callback for checking an architectural watchpoint + * match. * @debug_excp_handler: Callback for handling debug exceptions. * @write_elf64_note: Callback for writing a CPU-specific ELF note to a * 64-bit VM coredump. @@ -155,6 +157,7 @@ typedef struct CPUClass { hwaddr (*get_phys_page_debug)(CPUState *cpu, vaddr addr); int (*gdb_read_register)(CPUState *cpu, uint8_t *buf, int reg); int (*gdb_write_register)(CPUState *cpu, uint8_t *buf, int reg); + bool (*debug_check_watchpoint)(CPUState *cpu); void (*debug_excp_handler)(CPUState *cpu); int (*write_elf64_note)(WriteCoreDumpFunction f, CPUState *cpu, diff --git a/qom/cpu.c b/qom/cpu.c index 62f4b5d..def1298 100644 --- a/qom/cpu.c +++ b/qom/cpu.c @@ -186,6 +186,14 @@ static int cpu_common_gdb_write_register(CPUState *cpu, uint8_t *buf, int reg) return 0; } +static bool cpu_common_debug_check_watchpoint(CPUState *cpu) +{ + /* If no extra check is required, QEMU watchpoint match can be considered + * as an architectural match. + */ + return true; +} + bool target_words_bigendian(void); static bool cpu_common_virtio_is_big_endian(CPUState *cpu) { @@ -348,6 +356,7 @@ static void cpu_class_init(ObjectClass *klass, void *data) k->gdb_write_register = cpu_common_gdb_write_register; k->virtio_is_big_endian = cpu_common_virtio_is_big_endian; k->debug_excp_handler = cpu_common_noop; + k->debug_check_watchpoint = cpu_common_debug_check_watchpoint; k->cpu_exec_enter = cpu_common_noop; k->cpu_exec_exit = cpu_common_noop; k->cpu_exec_interrupt = cpu_common_exec_interrupt; -- 1.9.1
