qemu/include/exec/translator.h
Richard Henderson d3a2a1d803 accel/tcg: Introduce translator_use_goto_tb
Add a generic version of the common use_goto_tb test.

Various targets avoid the page crossing test for CONFIG_USER_ONLY,
but that is wrong: mmap and mprotect can change page permissions.

Reviewed-by: Max Filippov <jcmvbkbc@gmail.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-07-09 09:41:53 -07:00

194 lines
6.8 KiB
C

/*
* Generic intermediate code generation.
*
* Copyright (C) 2016-2017 Lluís Vilanova <vilanova@ac.upc.edu>
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*/
#ifndef EXEC__TRANSLATOR_H
#define EXEC__TRANSLATOR_H
/*
* Include this header from a target-specific file, and add a
*
* DisasContextBase base;
*
* member in your target-specific DisasContext.
*/
#include "qemu/bswap.h"
#include "exec/exec-all.h"
#include "exec/cpu_ldst.h"
#include "exec/plugin-gen.h"
#include "tcg/tcg.h"
/**
* DisasJumpType:
* @DISAS_NEXT: Next instruction in program order.
* @DISAS_TOO_MANY: Too many instructions translated.
* @DISAS_NORETURN: Following code is dead.
* @DISAS_TARGET_*: Start of target-specific conditions.
*
* What instruction to disassemble next.
*/
typedef enum DisasJumpType {
DISAS_NEXT,
DISAS_TOO_MANY,
DISAS_NORETURN,
DISAS_TARGET_0,
DISAS_TARGET_1,
DISAS_TARGET_2,
DISAS_TARGET_3,
DISAS_TARGET_4,
DISAS_TARGET_5,
DISAS_TARGET_6,
DISAS_TARGET_7,
DISAS_TARGET_8,
DISAS_TARGET_9,
DISAS_TARGET_10,
DISAS_TARGET_11,
} DisasJumpType;
/**
* DisasContextBase:
* @tb: Translation block for this disassembly.
* @pc_first: Address of first guest instruction in this TB.
* @pc_next: Address of next guest instruction in this TB (current during
* disassembly).
* @is_jmp: What instruction to disassemble next.
* @num_insns: Number of translated instructions (including current).
* @max_insns: Maximum number of instructions to be translated in this TB.
* @singlestep_enabled: "Hardware" single stepping enabled.
*
* Architecture-agnostic disassembly context.
*/
typedef struct DisasContextBase {
const TranslationBlock *tb;
target_ulong pc_first;
target_ulong pc_next;
DisasJumpType is_jmp;
int num_insns;
int max_insns;
bool singlestep_enabled;
} DisasContextBase;
/**
* TranslatorOps:
* @init_disas_context:
* Initialize the target-specific portions of DisasContext struct.
* The generic DisasContextBase has already been initialized.
*
* @tb_start:
* Emit any code required before the start of the main loop,
* after the generic gen_tb_start().
*
* @insn_start:
* Emit the tcg_gen_insn_start opcode.
*
* @breakpoint_check:
* When called, the breakpoint has already been checked to match the PC,
* but the target may decide the breakpoint missed the address
* (e.g., due to conditions encoded in their flags). Return true to
* indicate that the breakpoint did hit, in which case no more breakpoints
* are checked. If the breakpoint did hit, emit any code required to
* signal the exception, and set db->is_jmp as necessary to terminate
* the main loop.
*
* @translate_insn:
* Disassemble one instruction and set db->pc_next for the start
* of the following instruction. Set db->is_jmp as necessary to
* terminate the main loop.
*
* @tb_stop:
* Emit any opcodes required to exit the TB, based on db->is_jmp.
*
* @disas_log:
* Print instruction disassembly to log.
*/
typedef struct TranslatorOps {
void (*init_disas_context)(DisasContextBase *db, CPUState *cpu);
void (*tb_start)(DisasContextBase *db, CPUState *cpu);
void (*insn_start)(DisasContextBase *db, CPUState *cpu);
bool (*breakpoint_check)(DisasContextBase *db, CPUState *cpu,
const CPUBreakpoint *bp);
void (*translate_insn)(DisasContextBase *db, CPUState *cpu);
void (*tb_stop)(DisasContextBase *db, CPUState *cpu);
void (*disas_log)(const DisasContextBase *db, CPUState *cpu);
} TranslatorOps;
/**
* translator_loop:
* @ops: Target-specific operations.
* @db: Disassembly context.
* @cpu: Target vCPU.
* @tb: Translation block.
* @max_insns: Maximum number of insns to translate.
*
* Generic translator loop.
*
* Translation will stop in the following cases (in order):
* - When is_jmp set by #TranslatorOps::breakpoint_check.
* - set to DISAS_TOO_MANY exits after translating one more insn
* - set to any other value than DISAS_NEXT exits immediately.
* - When is_jmp set by #TranslatorOps::translate_insn.
* - set to any value other than DISAS_NEXT exits immediately.
* - When the TCG operation buffer is full.
* - When single-stepping is enabled (system-wide or on the current vCPU).
* - When too many instructions have been translated.
*/
void translator_loop(const TranslatorOps *ops, DisasContextBase *db,
CPUState *cpu, TranslationBlock *tb, int max_insns);
void translator_loop_temp_check(DisasContextBase *db);
/**
* translator_use_goto_tb
* @db: Disassembly context
* @dest: target pc of the goto
*
* Return true if goto_tb is allowed between the current TB
* and the destination PC.
*/
bool translator_use_goto_tb(DisasContextBase *db, target_ulong dest);
/*
* Translator Load Functions
*
* These are intended to replace the direct usage of the cpu_ld*_code
* functions and are mandatory for front-ends that have been migrated
* to the common translator_loop. These functions are only intended
* to be called from the translation stage and should not be called
* from helper functions. Those functions should be converted to encode
* the relevant information at translation time.
*/
#define GEN_TRANSLATOR_LD(fullname, type, load_fn, swap_fn) \
static inline type \
fullname ## _swap(CPUArchState *env, abi_ptr pc, bool do_swap) \
{ \
type ret = load_fn(env, pc); \
if (do_swap) { \
ret = swap_fn(ret); \
} \
plugin_insn_append(&ret, sizeof(ret)); \
return ret; \
} \
\
static inline type fullname(CPUArchState *env, abi_ptr pc) \
{ \
return fullname ## _swap(env, pc, false); \
}
GEN_TRANSLATOR_LD(translator_ldub, uint8_t, cpu_ldub_code, /* no swap */)
GEN_TRANSLATOR_LD(translator_ldsw, int16_t, cpu_ldsw_code, bswap16)
GEN_TRANSLATOR_LD(translator_lduw, uint16_t, cpu_lduw_code, bswap16)
GEN_TRANSLATOR_LD(translator_ldl, uint32_t, cpu_ldl_code, bswap32)
GEN_TRANSLATOR_LD(translator_ldq, uint64_t, cpu_ldq_code, bswap64)
#undef GEN_TRANSLATOR_LD
#endif /* EXEC__TRANSLATOR_H */