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tcg: rename tcg_current_cpu to tcg_current_rr_cpu
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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 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 "cpu.h"
22 #include "sysemu/cpus.h"
23 #include "exec/exec-all.h"
24 #include "exec/memory-internal.h"
25
26 bool exit_request;
27
28 /* exit the current TB, but without causing any exception to be raised */
29 void cpu_loop_exit_noexc(CPUState *cpu)
30 {
31 /* XXX: restore cpu registers saved in host registers */
32
33 cpu->exception_index = -1;
34 siglongjmp(cpu->jmp_env, 1);
35 }
36
37 #if defined(CONFIG_SOFTMMU)
38 void cpu_reloading_memory_map(void)
39 {
40 if (qemu_in_vcpu_thread()) {
41 /* The guest can in theory prolong the RCU critical section as long
42 * as it feels like. The major problem with this is that because it
43 * can do multiple reconfigurations of the memory map within the
44 * critical section, we could potentially accumulate an unbounded
45 * collection of memory data structures awaiting reclamation.
46 *
47 * Because the only thing we're currently protecting with RCU is the
48 * memory data structures, it's sufficient to break the critical section
49 * in this callback, which we know will get called every time the
50 * memory map is rearranged.
51 *
52 * (If we add anything else in the system that uses RCU to protect
53 * its data structures, we will need to implement some other mechanism
54 * to force TCG CPUs to exit the critical section, at which point this
55 * part of this callback might become unnecessary.)
56 *
57 * This pair matches cpu_exec's rcu_read_lock()/rcu_read_unlock(), which
58 * only protects cpu->as->dispatch. Since we know our caller is about
59 * to reload it, it's safe to split the critical section.
60 */
61 rcu_read_unlock();
62 rcu_read_lock();
63 }
64 }
65 #endif
66
67 void cpu_loop_exit(CPUState *cpu)
68 {
69 siglongjmp(cpu->jmp_env, 1);
70 }
71
72 void cpu_loop_exit_restore(CPUState *cpu, uintptr_t pc)
73 {
74 if (pc) {
75 cpu_restore_state(cpu, pc);
76 }
77 siglongjmp(cpu->jmp_env, 1);
78 }
79
80 void cpu_loop_exit_atomic(CPUState *cpu, uintptr_t pc)
81 {
82 cpu->exception_index = EXCP_ATOMIC;
83 cpu_loop_exit_restore(cpu, pc);
84 }