From 568496c0c0f1863a4bc18539962cd8d81baa4e30 Mon Sep 17 00:00:00 2001 From: Sergey Fedorov Date: Thu, 11 Feb 2016 11:17:32 +0000 Subject: [PATCH] cpu: Add callback to check architectural watchpoint match 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 Message-id: 1454256948-10485-2-git-send-email-serge.fdrv@gmail.com Reviewed-by: Peter Maydell Signed-off-by: Peter Maydell --- exec.c | 6 ++++++ include/qom/cpu.h | 8 ++++++-- qom/cpu.c | 9 +++++++++ 3 files changed, 21 insertions(+), 2 deletions(-) diff --git a/exec.c b/exec.c index 7d67c11601..07598d0acd 100644 --- a/exec.c +++ b/exec.c @@ -2070,6 +2070,7 @@ 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; @@ -2095,6 +2096,11 @@ static void check_watchpoint(int offset, int len, MemTxAttrs attrs, int flags) wp->hitaddr = vaddr; wp->hitattrs = attrs; if (!cpu->watchpoint_hit) { + if (wp->flags & BP_CPU && + !cc->debug_check_watchpoint(cpu, wp)) { + wp->flags &= ~BP_WATCHPOINT_HIT; + continue; + } cpu->watchpoint_hit = wp; tb_check_watchpoint(cpu); if (wp->flags & BP_STOP_BEFORE_ACCESS) { diff --git a/include/qom/cpu.h b/include/qom/cpu.h index 035179c09c..ff54600e71 100644 --- a/include/qom/cpu.h +++ b/include/qom/cpu.h @@ -64,6 +64,7 @@ typedef uint64_t vaddr; #define CPU_GET_CLASS(obj) OBJECT_GET_CLASS(CPUClass, (obj), TYPE_CPU) typedef struct CPUState CPUState; +typedef struct CPUWatchpoint CPUWatchpoint; typedef void (*CPUUnassignedAccess)(CPUState *cpu, hwaddr addr, bool is_write, bool is_exec, int opaque, @@ -106,6 +107,8 @@ struct TranslationBlock; * a memory access with the specified memory transaction attributes. * @gdb_read_register: Callback for letting GDB read a register. * @gdb_write_register: Callback for letting GDB write a register. + * @debug_check_watchpoint: Callback: return true if the architectural + * watchpoint whose address has matched should really fire. * @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. @@ -165,6 +168,7 @@ typedef struct CPUClass { int (*asidx_from_attrs)(CPUState *cpu, MemTxAttrs attrs); 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, CPUWatchpoint *wp); void (*debug_excp_handler)(CPUState *cpu); int (*write_elf64_note)(WriteCoreDumpFunction f, CPUState *cpu, @@ -207,14 +211,14 @@ typedef struct CPUBreakpoint { QTAILQ_ENTRY(CPUBreakpoint) entry; } CPUBreakpoint; -typedef struct CPUWatchpoint { +struct CPUWatchpoint { vaddr vaddr; vaddr len; vaddr hitaddr; MemTxAttrs hitattrs; int flags; /* BP_* */ QTAILQ_ENTRY(CPUWatchpoint) entry; -} CPUWatchpoint; +}; struct KVMState; struct kvm_run; diff --git a/qom/cpu.c b/qom/cpu.c index 38dc713ce2..aeb32f1b6e 100644 --- a/qom/cpu.c +++ b/qom/cpu.c @@ -189,6 +189,14 @@ 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, CPUWatchpoint *wp) +{ + /* 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) { @@ -353,6 +361,7 @@ 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;