cpu_instruction_query

Description

The cpu_instruction_query interface can be used in functions of the following types:

• cpu_instruction_cb_t
• cpu_cached_instruction_cb_t
• cpu_instruction_decoder_cb_t

where an instruction_handle_t pointer is available. The handle is only valid in the callback. The interface is used to request information about the instruction being executed by the processor cpu.

SIM_INTERFACE(cpu_instruction_query) {
        logical_address_t (*logical_address)(
                conf_object_t *cpu, instruction_handle_t *handle);
        physical_address_t (*physical_address)(
                conf_object_t *cpu, instruction_handle_t *handle);
        cpu_bytes_t (*get_instruction_bytes)(
                conf_object_t *cpu, instruction_handle_t *handle);
        bool (*is_existing_instruction)(
                conf_object_t *cpu, instruction_handle_t *handle);
};

#define CPU_INSTRUCTION_QUERY_INTERFACE "cpu_instruction_query"

The logical_address and physical_address is used to get the different addresses of the instruction being executed.

Note that if the instruction crosses a page boundary the last part of the instruction will have a different mapping for the physical address than returned by physical_address. To get hold of the physical address on the second page, use the logical_to_physical method of the processor_info(_v2) and provide the logical address of the first byte on the second page.

The get_instruction_bytes method is used to read the instruction bytes. The returned data is of a cpu_bytes_t type that contains the data and the size. The data member is only available during the execution of the callback. The data cannot be changed. Corresponding type in Python is a string of bytes.

typedef struct cpu_bytes {
        size_t size;
#ifndef PYWRAP
        const uint8 *data;
#endif
} cpu_bytes_t;

The is_existing_instruction method is used to determine if Simics managed to decode the instruction bytes. Note that despite this method returning false could imply that the instruction is implemented using a user supplied implementation through the x86_instrumentation_subscribe interface.

Additional information can be read out with an architectural specific query interface, see x86_instruction_query for details.

Execution Context

Threaded Context for all methods, but must be called from a callback receiving a handle of type instruction_handle_t.