Commit 568496c0 authored by Sergey Fedorov's avatar Sergey Fedorov Committed by Peter Maydell
Browse files

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: default avatarSergey Fedorov <serge.fdrv@gmail.com>
Message-id: 1454256948-10485-2-git-send-email-serge.fdrv@gmail.com
Reviewed-by: default avatarPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: default avatarPeter Maydell <peter.maydell@linaro.org>
parent 7d197d2d

exec.c

+6 −0
Original line number Diff line number Diff line
@@ -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) {

include/qom/cpu.h

+6 −2
Original line number Diff line number Diff line
@@ -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;

qom/cpu.c

+9 −0
Original line number Diff line number Diff line
@@ -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;