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32857f4d5e
Gather up all the fields currently in CPUState which deal with the CPU's AddressSpace into a separate CPUAddressSpace struct. This paves the way for allowing the CPU to know about more than one AddressSpace. The rearrangement also allows us to make the MemoryListener a directly embedded object in the CPUAddressSpace (it could not be embedded in CPUState because 'struct MemoryListener' isn't defined for the user-only builds). This allows us to resolve the FIXME in tcg_commit() by going directly from the MemoryListener to the CPUAddressSpace. This patch extracts the actual update of the cached dispatch pointer from cpu_reload_memory_map() (which is renamed accordingly to cpu_reloading_memory_map() as it is only responsible for breaking cpu-exec.c's RCU critical section now). This lets us keep the definition of the CPUAddressSpace struct private to exec.c. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Message-Id: <1443709790-25180-4-git-send-email-peter.maydell@linaro.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
83 lines
2.8 KiB
C
83 lines
2.8 KiB
C
/*
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* emulator main execution loop
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*
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* Copyright (c) 2003-2005 Fabrice Bellard
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, see <http://www.gnu.org/licenses/>.
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*/
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#include "config.h"
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#include "cpu.h"
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#include "sysemu/cpus.h"
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#include "exec/memory-internal.h"
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bool exit_request;
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CPUState *tcg_current_cpu;
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/* exit the current TB from a signal handler. The host registers are
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restored in a state compatible with the CPU emulator
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*/
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#if defined(CONFIG_SOFTMMU)
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void cpu_resume_from_signal(CPUState *cpu, void *puc)
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{
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/* XXX: restore cpu registers saved in host registers */
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cpu->exception_index = -1;
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siglongjmp(cpu->jmp_env, 1);
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}
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void cpu_reloading_memory_map(void)
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{
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if (qemu_in_vcpu_thread()) {
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/* The guest can in theory prolong the RCU critical section as long
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* as it feels like. The major problem with this is that because it
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* can do multiple reconfigurations of the memory map within the
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* critical section, we could potentially accumulate an unbounded
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* collection of memory data structures awaiting reclamation.
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*
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* Because the only thing we're currently protecting with RCU is the
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* memory data structures, it's sufficient to break the critical section
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* in this callback, which we know will get called every time the
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* memory map is rearranged.
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*
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* (If we add anything else in the system that uses RCU to protect
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* its data structures, we will need to implement some other mechanism
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* to force TCG CPUs to exit the critical section, at which point this
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* part of this callback might become unnecessary.)
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*
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* This pair matches cpu_exec's rcu_read_lock()/rcu_read_unlock(), which
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* only protects cpu->as->dispatch. Since we know our caller is about
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* to reload it, it's safe to split the critical section.
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*/
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rcu_read_unlock();
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rcu_read_lock();
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}
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}
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#endif
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void cpu_loop_exit(CPUState *cpu)
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{
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cpu->current_tb = NULL;
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siglongjmp(cpu->jmp_env, 1);
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}
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void cpu_loop_exit_restore(CPUState *cpu, uintptr_t pc)
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{
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if (pc) {
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cpu_restore_state(cpu, pc);
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}
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cpu->current_tb = NULL;
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siglongjmp(cpu->jmp_env, 1);
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}
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