vhost: fail backend intialization early
[qemu/ar7.git] / cpu-exec-common.c
blob16d305b911e4e5661589749b80481777f424619e
1 /*
2 * emulator main execution loop
4 * Copyright (c) 2003-2005 Fabrice Bellard
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.
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.
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/>.
20 #include "config.h"
21 #include "cpu.h"
22 #include "sysemu/cpus.h"
23 #include "exec/memory-internal.h"
25 bool exit_request;
26 CPUState *tcg_current_cpu;
28 /* exit the current TB from a signal handler. The host registers are
29 restored in a state compatible with the CPU emulator
31 #if defined(CONFIG_SOFTMMU)
32 void cpu_resume_from_signal(CPUState *cpu, void *puc)
34 /* XXX: restore cpu registers saved in host registers */
36 cpu->exception_index = -1;
37 siglongjmp(cpu->jmp_env, 1);
40 void cpu_reload_memory_map(CPUState *cpu)
42 AddressSpaceDispatch *d;
44 if (qemu_in_vcpu_thread()) {
45 /* Do not let the guest prolong the critical section as much as it
46 * as it desires.
48 * Currently, this is prevented by the I/O thread's periodinc kicking
49 * of the VCPU thread (iothread_requesting_mutex, qemu_cpu_kick_thread)
50 * but this will go away once TCG's execution moves out of the global
51 * mutex.
53 * This pair matches cpu_exec's rcu_read_lock()/rcu_read_unlock(), which
54 * only protects cpu->as->dispatch. Since we reload it below, we can
55 * split the critical section.
57 rcu_read_unlock();
58 rcu_read_lock();
61 /* The CPU and TLB are protected by the iothread lock. */
62 d = atomic_rcu_read(&cpu->as->dispatch);
63 cpu->memory_dispatch = d;
64 tlb_flush(cpu, 1);
66 #endif
68 void cpu_loop_exit(CPUState *cpu)
70 cpu->current_tb = NULL;
71 siglongjmp(cpu->jmp_env, 1);
74 void cpu_loop_exit_restore(CPUState *cpu, uintptr_t pc)
76 if (pc) {
77 cpu_restore_state(cpu, pc);
79 cpu->current_tb = NULL;
80 siglongjmp(cpu->jmp_env, 1);