xref: /qemu/accel/tcg/cpu-exec-common.c (revision 1501743654692ae6acf98ed8ec162b256eb54a64)
1 /*
2  *  emulator main execution loop
3  *
4  *  Copyright (c) 2003-2005 Fabrice Bellard
5  *
6  * This library is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * This library is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
18  */
19 
20 #include "qemu/osdep.h"
21 #include "exec/log.h"
22 #include "system/cpus.h"
23 #include "system/tcg.h"
24 #include "qemu/plugin.h"
25 #include "internal-common.h"
26 
27 bool tcg_allowed;
28 
29 bool tcg_cflags_has(CPUState *cpu, uint32_t flags)
30 {
31     return cpu->tcg_cflags & flags;
32 }
33 
34 void tcg_cflags_set(CPUState *cpu, uint32_t flags)
35 {
36     cpu->tcg_cflags |= flags;
37 }
38 
39 uint32_t curr_cflags(CPUState *cpu)
40 {
41     uint32_t cflags = cpu->tcg_cflags;
42 
43     /*
44      * Record gdb single-step.  We should be exiting the TB by raising
45      * EXCP_DEBUG, but to simplify other tests, disable chaining too.
46      *
47      * For singlestep and -d nochain, suppress goto_tb so that
48      * we can log -d cpu,exec after every TB.
49      */
50     if (unlikely(cpu->singlestep_enabled)) {
51         cflags |= CF_NO_GOTO_TB | CF_NO_GOTO_PTR | CF_SINGLE_STEP | 1;
52     } else if (qatomic_read(&one_insn_per_tb)) {
53         cflags |= CF_NO_GOTO_TB | 1;
54     } else if (qemu_loglevel_mask(CPU_LOG_TB_NOCHAIN)) {
55         cflags |= CF_NO_GOTO_TB;
56     }
57 
58     return cflags;
59 }
60 
61 /* exit the current TB, but without causing any exception to be raised */
62 void cpu_loop_exit_noexc(CPUState *cpu)
63 {
64     cpu->exception_index = -1;
65     cpu_loop_exit(cpu);
66 }
67 
68 void cpu_loop_exit(CPUState *cpu)
69 {
70     /* Undo the setting in cpu_tb_exec.  */
71     cpu->neg.can_do_io = true;
72     /* Undo any setting in generated code.  */
73     qemu_plugin_disable_mem_helpers(cpu);
74     siglongjmp(cpu->jmp_env, 1);
75 }
76 
77 void cpu_loop_exit_restore(CPUState *cpu, uintptr_t pc)
78 {
79     if (pc) {
80         cpu_restore_state(cpu, pc);
81     }
82     cpu_loop_exit(cpu);
83 }
84 
85 void cpu_loop_exit_atomic(CPUState *cpu, uintptr_t pc)
86 {
87     /* Prevent looping if already executing in a serial context. */
88     g_assert(!cpu_in_serial_context(cpu));
89     cpu->exception_index = EXCP_ATOMIC;
90     cpu_loop_exit_restore(cpu, pc);
91 }
92