aboutsummaryrefslogtreecommitdiff
path: root/accel/tcg/translator.c
blob: 8e78fd7a9c962649e8b763018e6a8c36428851f3 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
/*
 * 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.
 */

#include "qemu/osdep.h"
#include "qemu/error-report.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"
#include "exec/plugin-gen.h"
#include "sysemu/replay.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);
    }
}

bool translator_use_goto_tb(DisasContextBase *db, target_ulong dest)
{
    /* Suppress goto_tb if requested. */
    if (tb_cflags(db->tb) & CF_NO_GOTO_TB) {
        return false;
    }

    /* Check for the dest on the same page as the start of the TB.  */
    return ((db->pc_first ^ dest) & TARGET_PAGE_MASK) == 0;
}

void translator_loop(CPUState *cpu, TranslationBlock *tb, int max_insns,
                     target_ulong pc, void *host_pc,
                     const TranslatorOps *ops, DisasContextBase *db)
{
    uint32_t cflags = tb_cflags(tb);
    bool plugin_enabled;

    /* Initialize DisasContext */
    db->tb = tb;
    db->pc_first = pc;
    db->pc_next = pc;
    db->is_jmp = DISAS_NEXT;
    db->num_insns = 0;
    db->max_insns = max_insns;
    db->singlestep_enabled = cflags & CF_SINGLE_STEP;
    db->host_addr[0] = host_pc;
    db->host_addr[1] = NULL;

#ifdef CONFIG_USER_ONLY
    page_protect(pc);
#endif

    ops->init_disas_context(db, cpu);
    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 */

    plugin_enabled = plugin_gen_tb_start(cpu, db, cflags & CF_MEMI_ONLY);

    while (true) {
        db->num_insns++;
        ops->insn_start(db, cpu);
        tcg_debug_assert(db->is_jmp == DISAS_NEXT);  /* no early exit */

        if (plugin_enabled) {
            plugin_gen_insn_start(cpu, db);
        }

        /* 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 == db->max_insns && (cflags & CF_LAST_IO)) {
            /* Accept I/O on the last instruction.  */
            gen_io_start();
            ops->translate_insn(db, cpu);
        } else {
            /* we should only see CF_MEMI_ONLY for io_recompile */
            tcg_debug_assert(!(cflags & CF_MEMI_ONLY));
            ops->translate_insn(db, cpu);
        }

        /* Stop translation if translate_insn so indicated.  */
        if (db->is_jmp != DISAS_NEXT) {
            break;
        }

        /*
         * We can't instrument after instructions that change control
         * flow although this only really affects post-load operations.
         */
        if (plugin_enabled) {
            plugin_gen_insn_end();
        }

        /* 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 >= db->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);

    if (plugin_enabled) {
        plugin_gen_tb_end(cpu);
    }

    /* The disas_log hook may use these values rather than recompute.  */
    tb->size = db->pc_next - db->pc_first;
    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)) {
        FILE *logfile = qemu_log_trylock();
        if (logfile) {
            fprintf(logfile, "----------------\n");
            ops->disas_log(db, cpu, logfile);
            fprintf(logfile, "\n");
            qemu_log_unlock(logfile);
        }
    }
#endif
}

static void *translator_access(CPUArchState *env, DisasContextBase *db,
                               target_ulong pc, size_t len)
{
    void *host;
    target_ulong base, end;
    TranslationBlock *tb;

    tb = db->tb;

    /* Use slow path if first page is MMIO. */
    if (unlikely(tb->page_addr[0] == -1)) {
        return NULL;
    }

    end = pc + len - 1;
    if (likely(is_same_page(db, end))) {
        host = db->host_addr[0];
        base = db->pc_first;
    } else {
        host = db->host_addr[1];
        base = TARGET_PAGE_ALIGN(db->pc_first);
        if (host == NULL) {
            tb->page_addr[1] =
                get_page_addr_code_hostp(env, base, &db->host_addr[1]);
#ifdef CONFIG_USER_ONLY
            page_protect(end);
#endif
            /* We cannot handle MMIO as second page. */
            assert(tb->page_addr[1] != -1);
            host = db->host_addr[1];
        }

        /* Use slow path when crossing pages. */
        if (is_same_page(db, pc)) {
            return NULL;
        }
    }

    tcg_debug_assert(pc >= base);
    return host + (pc - base);
}

uint8_t translator_ldub(CPUArchState *env, DisasContextBase *db, abi_ptr pc)
{
    uint8_t ret;
    void *p = translator_access(env, db, pc, sizeof(ret));

    if (p) {
        plugin_insn_append(pc, p, sizeof(ret));
        return ldub_p(p);
    }
    ret = cpu_ldub_code(env, pc);
    plugin_insn_append(pc, &ret, sizeof(ret));
    return ret;
}

uint16_t translator_lduw(CPUArchState *env, DisasContextBase *db, abi_ptr pc)
{
    uint16_t ret, plug;
    void *p = translator_access(env, db, pc, sizeof(ret));

    if (p) {
        plugin_insn_append(pc, p, sizeof(ret));
        return lduw_p(p);
    }
    ret = cpu_lduw_code(env, pc);
    plug = tswap16(ret);
    plugin_insn_append(pc, &plug, sizeof(ret));
    return ret;
}

uint32_t translator_ldl(CPUArchState *env, DisasContextBase *db, abi_ptr pc)
{
    uint32_t ret, plug;
    void *p = translator_access(env, db, pc, sizeof(ret));

    if (p) {
        plugin_insn_append(pc, p, sizeof(ret));
        return ldl_p(p);
    }
    ret = cpu_ldl_code(env, pc);
    plug = tswap32(ret);
    plugin_insn_append(pc, &plug, sizeof(ret));
    return ret;
}

uint64_t translator_ldq(CPUArchState *env, DisasContextBase *db, abi_ptr pc)
{
    uint64_t ret, plug;
    void *p = translator_access(env, db, pc, sizeof(ret));

    if (p) {
        plugin_insn_append(pc, p, sizeof(ret));
        return ldq_p(p);
    }
    ret = cpu_ldq_code(env, pc);
    plug = tswap64(ret);
    plugin_insn_append(pc, &plug, sizeof(ret));
    return ret;
}