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 <serge.fdrv@gmail.com>
Message-id: 1454256948-10485-2-git-send-email-serge.fdrv@gmail.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This commit is contained in:
Sergey Fedorov 2016-02-11 11:17:32 +00:00 committed by Peter Maydell
parent 7d197d2db5
commit 568496c0c0
3 changed files with 21 additions and 2 deletions

6
exec.c
View File

@ -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) {

View File

@ -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;

View File

@ -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;