/* * emulator main execution loop * * Copyright (c) 2003-2005 Fabrice Bellard * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, see <http://www.gnu.org/licenses/>. */ #include "config.h" #include "cpu.h" #include "sysemu/cpus.h" #include "exec/memory-internal.h" bool exit_request; CPUState *tcg_current_cpu; /* exit the current TB from a signal handler. The host registers are restored in a state compatible with the CPU emulator */ #if defined(CONFIG_SOFTMMU) void cpu_resume_from_signal(CPUState *cpu, void *puc) { /* XXX: restore cpu registers saved in host registers */ cpu->exception_index = -1; siglongjmp(cpu->jmp_env, 1); } void cpu_reloading_memory_map(void) { if (qemu_in_vcpu_thread()) { /* The guest can in theory prolong the RCU critical section as long * as it feels like. The major problem with this is that because it * can do multiple reconfigurations of the memory map within the * critical section, we could potentially accumulate an unbounded * collection of memory data structures awaiting reclamation. * * Because the only thing we're currently protecting with RCU is the * memory data structures, it's sufficient to break the critical section * in this callback, which we know will get called every time the * memory map is rearranged. * * (If we add anything else in the system that uses RCU to protect * its data structures, we will need to implement some other mechanism * to force TCG CPUs to exit the critical section, at which point this * part of this callback might become unnecessary.) * * This pair matches cpu_exec's rcu_read_lock()/rcu_read_unlock(), which * only protects cpu->as->dispatch. Since we know our caller is about * to reload it, it's safe to split the critical section. */ rcu_read_unlock(); rcu_read_lock(); } } #endif void cpu_loop_exit(CPUState *cpu) { cpu->current_tb = NULL; siglongjmp(cpu->jmp_env, 1); } void cpu_loop_exit_restore(CPUState *cpu, uintptr_t pc) { if (pc) { cpu_restore_state(cpu, pc); } cpu->current_tb = NULL; siglongjmp(cpu->jmp_env, 1); }