Lluís Vilanova <vilan...@ac.upc.edu> writes:
> Signed-off-by: Lluís Vilanova <vilan...@ac.upc.edu>
> ---
> accel/tcg/Makefile.objs | 1
> accel/tcg/translator.c | 152
> +++++++++++++++++++++++++++++++++++++++++++++
> include/exec/gen-icount.h | 2 -
> include/exec/translator.h | 99 +++++++++++++++++++++++++++++
> 4 files changed, 253 insertions(+), 1 deletion(-)
> create mode 100644 accel/tcg/translator.c
>
> diff --git a/accel/tcg/Makefile.objs b/accel/tcg/Makefile.objs
> index f173cd5397..3a5da5357c 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 translate-common.o
> +obj-y += translator.o
There is a merge conflict here with the current master.
> diff --git a/accel/tcg/translator.c b/accel/tcg/translator.c
> new file mode 100644
> index 0000000000..9e0343cbb1
> --- /dev/null
> +++ b/accel/tcg/translator.c
> @@ -0,0 +1,152 @@
> +/*
> + * Generic intermediate code generation.
> + *
> + * Copyright (C) 2016-2017 Lluís Vilanova <vilan...@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.
> + */
> +
> +#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"
> +
> +
> +static inline void translate_block_tcg_check(const DisasContextBase *db)
> +{
> + if (tcg_check_temp_count()) {
> + error_report("warning: TCG temporary leaks before "TARGET_FMT_lx,
> + 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;
> + ops->init_disas_context(db, cpu);
> +
> + /* Initialize globals */
> + tcg_clear_temp_count();
> +
> + /* 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;
> + }
> +
> + /* Start translating */
> + gen_tb_start(db->tb);
> + ops->tb_start(db, cpu);
> +
> + while (true) {
> + db->num_insns++;
> + ops->insn_start(db, cpu);
> +
> + /* Early exit before breakpoint checks */
> + if (unlikely(db->is_jmp != DISAS_NEXT)) {
> + break;
> + }
> +
> + /* 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) {
> + BreakpointCheckType bp_check =
> + ops->breakpoint_check(db, cpu, bp);
> + switch (bp_check) {
> + case BC_MISS:
> + /* Target ignored this breakpoint, go to next */
> + break;
> + case BC_HIT_INSN:
> + /* Hit, keep translating */
> + /*
> + * TODO: if we're never going to have more than one
> + * BP in a single address, we can simply use a
> + * bool here.
> + */
> + goto done_breakpoints;
> + case BC_HIT_TB:
> + /* Hit, end TB */
> + goto done_generating;
> + default:
> + g_assert_not_reached();
> + }
> + }
> + }
> + }
> + done_breakpoints:
For the sake of keeping the core loop easy to follow maybe it would be
better to have a helper function for the breakpoint handling? Really
there is only one result from the helper which is do we continue the
loop or jump to done_generating.
> +
> + /* Accept I/O on last instruction */
> + if (db->num_insns == max_insns && (db->tb->cflags & CF_LAST_IO)) {
> + gen_io_start();
> + }
> +
> + /* Disassemble one instruction */
> + db->pc_next = ops->translate_insn(db, cpu);
> +
> + /**************************************************/
> + /* Conditions to stop translation */
> + /**************************************************/
> +
> + /* Target-specific conditions set by disassembly */
> + if (db->is_jmp != DISAS_NEXT) {
> + break;
> + }
> +
> + /* Too many instructions */
> + if (tcg_op_buf_full() || db->num_insns >= max_insns) {
> + db->is_jmp = DISAS_TOO_MANY;
> + break;
> + }
> +
> + translate_block_tcg_check(db);
> + }
This may be a personal taste thing but having while(true) {} and breaks
is harder to follow than do { stuff } while (!done);
> +
> + ops->tb_stop(db, cpu);
> +
> + if (db->tb->cflags & CF_LAST_IO) {
> + gen_io_end();
> + }
> +
> +done_generating:
> + gen_tb_end(db->tb, db->num_insns);
> +
> + translate_block_tcg_check(db);
> +
> +#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
> +
> + db->tb->size = db->pc_next - db->pc_first;
> + db->tb->icount = db->num_insns;
> +}
> diff --git a/include/exec/gen-icount.h b/include/exec/gen-icount.h
> index 6c28ef59c3..9b3cb14dfa 100644
> --- a/include/exec/gen-icount.h
> +++ b/include/exec/gen-icount.h
> @@ -44,7 +44,7 @@ static inline void gen_tb_start(TranslationBlock *tb)
> tcg_temp_free_i32(count);
> }
>
> -static void gen_tb_end(TranslationBlock *tb, int num_insns)
> +static inline void gen_tb_end(TranslationBlock *tb, int num_insns)
> {
> if (tb->cflags & CF_USE_ICOUNT) {
> /* Update the num_insn immediate parameter now that we know
> diff --git a/include/exec/translator.h b/include/exec/translator.h
> index 1f9697dd31..f96b66f2bf 100644
> --- a/include/exec/translator.h
> +++ b/include/exec/translator.h
> @@ -10,6 +10,38 @@
> #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"
> +
> +
> +/**
> + * BreakpointCheckType:
> + * @BC_MISS: No hit
> + * @BC_HIT_INSN: Hit, but continue translating TB
> + * @BC_HIT_TB: Hit, stop translating TB
> + *
> + * How to react to a breakpoint. A hit means no more breakpoints will be
> checked
> + * for the current instruction.
> + *
> + * Not all breakpoints associated to an address are necessarily raised by
> + * targets (e.g., due to conditions encoded in their flags), so they can
> decide
> + * that a breakpoint missed the address (@BP_MISS).
> + */
> +typedef enum BreakpointCheckType {
> + BC_MISS,
> + BC_HIT_INSN,
> + BC_HIT_TB,
> +} BreakpointCheckType;
> +
> /**
> * DisasJumpType:
> * @DISAS_NEXT: Next instruction in program order.
> @@ -36,4 +68,71 @@ typedef enum DisasJumpType {
> DISAS_TARGET_12,
> } 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 a DisasContext struct (DisasContextBase
> has
> + * already been initialized).
> + * @tb_start: Start translating a new TB.
> + * @insn_start: Start translating a new instruction.
> + * @breakpoint_check: Check if a breakpoint did hit. When called, the
> breakpoint
> + * has already been checked to match the PC.
> + * @translate_insn: Disassemble one instruction and return the PC for the
> next
> + * one. Can set db->is_jmp to DISAS_TARGET or above to stop
> + * translation.
> + * @tb_stop: Stop translating a TB.
> + * @disas_log: Print instruction disassembly to log.
> + *
> + * Target-specific operations for the generic translator loop.
> + */
> +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);
> + BreakpointCheckType (*breakpoint_check)(DisasContextBase *db, CPUState
> *cpu,
> + const CPUBreakpoint *bp);
> + target_ulong (*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 set by #TranslatorOps::insn_start.
> + * - When set by #TranslatorOps::translate_insn.
> + * - 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);
> +
> #endif /* EXEC__TRANSLATOR_H */
--
Alex Bennée
