diff --git a/accel/tcg/Makefile.objs b/accel/tcg/Makefile.objs index 70cd474c01a0..22642e6f7518 100644 --- a/accel/tcg/Makefile.objs +++ b/accel/tcg/Makefile.objs @@ -1,3 +1,4 @@ obj-$(CONFIG_SOFTMMU) += tcg-all.o obj-$(CONFIG_SOFTMMU) += cputlb.o obj-y += cpu-exec.o cpu-exec-common.o translate-all.o +obj-y += translator.o diff --git a/accel/tcg/translator.c b/accel/tcg/translator.c new file mode 100644 index 000000000000..afa3af478aa5 --- /dev/null +++ b/accel/tcg/translator.c @@ -0,0 +1,138 @@ +/* + * Generic intermediate code generation. + * + * Copyright (C) 2016-2017 Lluís Vilanova + * + * This work is licensed under the terms of the GNU GPL, version 2 or later. + * See the COPYING file in the top-level directory. + */ + +#include "qemu/osdep.h" +#include "qemu-common.h" +#include "qemu/error-report.h" +#include "cpu.h" +#include "tcg/tcg.h" +#include "tcg/tcg-op.h" +#include "exec/exec-all.h" +#include "exec/gen-icount.h" +#include "exec/log.h" +#include "exec/translator.h" + +/* Pairs with tcg_clear_temp_count. + To be called by #TranslatorOps.{translate_insn,tb_stop} if + (1) the target is sufficiently clean to support reporting, + (2) as and when all temporaries are known to be consumed. + For most targets, (2) is at the end of translate_insn. */ +void translator_loop_temp_check(DisasContextBase *db) +{ + if (tcg_check_temp_count()) { + qemu_log("warning: TCG temporary leaks before " + TARGET_FMT_lx "\n", db->pc_next); + } +} + +void translator_loop(const TranslatorOps *ops, DisasContextBase *db, + CPUState *cpu, TranslationBlock *tb) +{ + int max_insns; + + /* Initialize DisasContext */ + db->tb = tb; + db->pc_first = tb->pc; + db->pc_next = db->pc_first; + db->is_jmp = DISAS_NEXT; + db->num_insns = 0; + db->singlestep_enabled = cpu->singlestep_enabled; + + /* Instruction counting */ + max_insns = db->tb->cflags & CF_COUNT_MASK; + if (max_insns == 0) { + max_insns = CF_COUNT_MASK; + } + if (max_insns > TCG_MAX_INSNS) { + max_insns = TCG_MAX_INSNS; + } + if (db->singlestep_enabled || singlestep) { + max_insns = 1; + } + + max_insns = ops->init_disas_context(db, cpu, max_insns); + tcg_debug_assert(db->is_jmp == DISAS_NEXT); /* no early exit */ + + /* Reset the temp count so that we can identify leaks */ + tcg_clear_temp_count(); + + /* Start translating. */ + gen_tb_start(db->tb); + ops->tb_start(db, cpu); + tcg_debug_assert(db->is_jmp == DISAS_NEXT); /* no early exit */ + + while (true) { + db->num_insns++; + ops->insn_start(db, cpu); + tcg_debug_assert(db->is_jmp == DISAS_NEXT); /* no early exit */ + + /* Pass breakpoint hits to target for further processing */ + if (unlikely(!QTAILQ_EMPTY(&cpu->breakpoints))) { + CPUBreakpoint *bp; + QTAILQ_FOREACH(bp, &cpu->breakpoints, entry) { + if (bp->pc == db->pc_next) { + if (ops->breakpoint_check(db, cpu, bp)) { + break; + } + } + } + /* The breakpoint_check hook may use DISAS_TOO_MANY to indicate + that only one more instruction is to be executed. Otherwise + it should use DISAS_NORETURN when generating an exception, + but may use a DISAS_TARGET_* value for Something Else. */ + if (db->is_jmp > DISAS_TOO_MANY) { + break; + } + } + + /* Disassemble one instruction. The translate_insn hook should + update db->pc_next and db->is_jmp to indicate what should be + done next -- either exiting this loop or locate the start of + the next instruction. */ + if (db->num_insns == max_insns && (db->tb->cflags & CF_LAST_IO)) { + /* Accept I/O on the last instruction. */ + gen_io_start(); + ops->translate_insn(db, cpu); + gen_io_end(); + } else { + ops->translate_insn(db, cpu); + } + + /* Stop translation if translate_insn so indicated. */ + if (db->is_jmp != DISAS_NEXT) { + break; + } + + /* Stop translation if the output buffer is full, + or we have executed all of the allowed instructions. */ + if (tcg_op_buf_full() || db->num_insns >= max_insns) { + db->is_jmp = DISAS_TOO_MANY; + break; + } + } + + /* Emit code to exit the TB, as indicated by db->is_jmp. */ + ops->tb_stop(db, cpu); + gen_tb_end(db->tb, db->num_insns); + + /* The disas_log hook may use these values rather than recompute. */ + db->tb->size = db->pc_next - db->pc_first; + db->tb->icount = db->num_insns; + +#ifdef DEBUG_DISAS + if (qemu_loglevel_mask(CPU_LOG_TB_IN_ASM) + && qemu_log_in_addr_range(db->pc_first)) { + qemu_log_lock(); + qemu_log("----------------\n"); + ops->disas_log(db, cpu); + qemu_log("\n"); + qemu_log_unlock(); + } +#endif +} diff --git a/include/exec/translator.h b/include/exec/translator.h index b51b8f8a4e61..e2dc2a04ae37 100644 --- a/include/exec/translator.h +++ b/include/exec/translator.h @@ -10,6 +10,19 @@ #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 "exec/exec-all.h" +#include "tcg/tcg.h" + + /** * DisasJumpType: * @DISAS_NEXT: Next instruction in program order. @@ -37,4 +50,95 @@ typedef enum DisasJumpType { 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). + * @singlestep_enabled: "Hardware" single stepping enabled. + * + * Architecture-agnostic disassembly context. + */ +typedef struct DisasContextBase { + TranslationBlock *tb; + target_ulong pc_first; + target_ulong pc_next; + DisasJumpType is_jmp; + unsigned int num_insns; + bool singlestep_enabled; +} DisasContextBase; + +/** + * TranslatorOps: + * @init_disas_context: + * Initialize the target-specific portions of DisasContext struct. + * The generic DisasContextBase has already been initialized. + * Return max_insns, modified as necessary by db->tb->flags. + * + * @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 { + int (*init_disas_context)(DisasContextBase *db, CPUState *cpu, + int max_insns); + 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. + * + * 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); + +void translator_loop_temp_check(DisasContextBase *db); + #endif /* EXEC__TRANSLATOR_H */