2  * CPU thread main loop - common bits for user and system mode emulation
4  *  Copyright (c) 2003-2005 Fabrice Bellard
16  * You should have received a copy of the GNU Lesser General Public
21 #include "qemu/main-loop.h"
22 #include "exec/cpu-common.h"
25 #include "trace/trace-root.h"
66         if (some_cpu->cpu_index >= max_cpu_index) {  in cpu_get_free_index()
67             max_cpu_index = some_cpu->cpu_index + 1;  in cpu_get_free_index()
86     if (cpu->cpu_index == UNASSIGNED_CPU_INDEX) {  in cpu_list_add()
88         cpu->cpu_index = cpu_get_free_index();  in cpu_list_add()
89         assert(cpu->cpu_index != UNASSIGNED_CPU_INDEX);  in cpu_list_add()
106     cpu->cpu_index = UNASSIGNED_CPU_INDEX;  in cpu_list_remove()
115         if (cpu->cpu_index == index) {  in qemu_get_cpu()
135     qemu_mutex_lock(&cpu->work_mutex);  in queue_work_on_cpu()
136     QSIMPLEQ_INSERT_TAIL(&cpu->work_list, wi, node);  in queue_work_on_cpu()
137     wi->done = false;  in queue_work_on_cpu()
138     qemu_mutex_unlock(&cpu->work_mutex);  in queue_work_on_cpu()
173     wi->func = func;  in async_run_on_cpu()
174     wi->data = data;  in async_run_on_cpu()
175     wi->free = true;  in async_run_on_cpu()
197     g_assert(!current_cpu->running);  in start_exclusive()
199     if (current_cpu->exclusive_context_count) {  in start_exclusive()
200         current_cpu->exclusive_context_count++;  in start_exclusive()
210     /* Write pending_cpus before reading other_cpu->running.  */  in start_exclusive()
214         if (qatomic_read(&other_cpu->running)) {  in start_exclusive()
215             other_cpu->has_waiter = true;  in start_exclusive()
231     current_cpu->exclusive_context_count = 1;  in start_exclusive()
237     current_cpu->exclusive_context_count--;  in end_exclusive()
238     if (current_cpu->exclusive_context_count) {  in end_exclusive()
251     qatomic_set(&cpu->running, true);  in cpu_exec_start()
253     /* Write cpu->running before reading pending_cpus.  */  in cpu_exec_start()
256     /* 1. start_exclusive saw cpu->running == true and pending_cpus >= 1.  in cpu_exec_start()
257      * After taking the lock we'll see cpu->has_waiter == true and run---not  in cpu_exec_start()
261      * 2. start_exclusive saw cpu->running == false but pending_cpus >= 1.  in cpu_exec_start()
262      * This includes the case when an exclusive item is running now.  in cpu_exec_start()
263      * Then we'll see cpu->has_waiter == false and wait for the item to  in cpu_exec_start()
267      * see cpu->running == true, and it will kick the CPU.  in cpu_exec_start()
271         if (!cpu->has_waiter) {  in cpu_exec_start()
272             /* Not counted in pending_cpus, let the exclusive item  in cpu_exec_start()
273              * run.  Since we have the lock, just set cpu->running to true  in cpu_exec_start()
276             qatomic_set(&cpu->running, false);  in cpu_exec_start()
279             qatomic_set(&cpu->running, true);  in cpu_exec_start()
291     qatomic_set(&cpu->running, false);  in cpu_exec_end()
293     /* Write cpu->running before reading pending_cpus.  */  in cpu_exec_end()
296     /* 1. start_exclusive saw cpu->running == true.  Then it will increment  in cpu_exec_end()
298      * we'll see cpu->has_waiter == true.  in cpu_exec_end()
300      * 2. start_exclusive saw cpu->running == false but here pending_cpus >= 1.  in cpu_exec_end()
301      * This includes the case when an exclusive item started after setting  in cpu_exec_end()
302      * cpu->running to false and before we read pending_cpus.  Then we'll see  in cpu_exec_end()
303      * cpu->has_waiter == false and not touch pending_cpus.  The next call to  in cpu_exec_end()
305      * for the item to complete.  in cpu_exec_end()
308      * see cpu->running == false, and it can ignore this CPU until the  in cpu_exec_end()
313         if (cpu->has_waiter) {  in cpu_exec_end()
314             cpu->has_waiter = false;  in cpu_exec_end()
315             qatomic_set(&pending_cpus, pending_cpus - 1);  in cpu_exec_end()
329     wi->func = func;  in async_safe_run_on_cpu()
330     wi->data = data;  in async_safe_run_on_cpu()
331     wi->free = true;  in async_safe_run_on_cpu()
332     wi->exclusive = true;  in async_safe_run_on_cpu()
339     while (!QSIMPLEQ_EMPTY(&cpu->work_list)) {  in free_queued_cpu_work()
340         struct qemu_work_item *wi = QSIMPLEQ_FIRST(&cpu->work_list);  in free_queued_cpu_work()
341         QSIMPLEQ_REMOVE_HEAD(&cpu->work_list, node);  in free_queued_cpu_work()
342         if (wi->free) {  in free_queued_cpu_work()
352     qemu_mutex_lock(&cpu->work_mutex);  in process_queued_cpu_work()
353     if (QSIMPLEQ_EMPTY(&cpu->work_list)) {  in process_queued_cpu_work()
354         qemu_mutex_unlock(&cpu->work_mutex);  in process_queued_cpu_work()
357     while (!QSIMPLEQ_EMPTY(&cpu->work_list)) {  in process_queued_cpu_work()
358         wi = QSIMPLEQ_FIRST(&cpu->work_list);  in process_queued_cpu_work()
359         QSIMPLEQ_REMOVE_HEAD(&cpu->work_list, node);  in process_queued_cpu_work()
360         qemu_mutex_unlock(&cpu->work_mutex);  in process_queued_cpu_work()
361         if (wi->exclusive) {  in process_queued_cpu_work()
370             wi->func(cpu, wi->data);  in process_queued_cpu_work()
374             wi->func(cpu, wi->data);  in process_queued_cpu_work()
376         qemu_mutex_lock(&cpu->work_mutex);  in process_queued_cpu_work()
377         if (wi->free) {  in process_queued_cpu_work()
380             qatomic_store_release(&wi->done, true);  in process_queued_cpu_work()
383     qemu_mutex_unlock(&cpu->work_mutex);  in process_queued_cpu_work()
393     if (cpu->cc->gdb_adjust_breakpoint) {  in cpu_breakpoint_insert()
394         pc = cpu->cc->gdb_adjust_breakpoint(cpu, pc);  in cpu_breakpoint_insert()
399     bp->pc = pc;  in cpu_breakpoint_insert()
400     bp->flags = flags;  in cpu_breakpoint_insert()
402     /* keep all GDB-injected breakpoints in front */  in cpu_breakpoint_insert()
404         QTAILQ_INSERT_HEAD(&cpu->breakpoints, bp, entry);  in cpu_breakpoint_insert()
406         QTAILQ_INSERT_TAIL(&cpu->breakpoints, bp, entry);  in cpu_breakpoint_insert()
413     trace_breakpoint_insert(cpu->cpu_index, pc, flags);  in cpu_breakpoint_insert()
422     if (cpu->cc->gdb_adjust_breakpoint) {  in cpu_breakpoint_remove()
423         pc = cpu->cc->gdb_adjust_breakpoint(cpu, pc);  in cpu_breakpoint_remove()
426     QTAILQ_FOREACH(bp, &cpu->breakpoints, entry) {  in cpu_breakpoint_remove()
427         if (bp->pc == pc && bp->flags == flags) {  in cpu_breakpoint_remove()
432     return -ENOENT;  in cpu_breakpoint_remove()
438     QTAILQ_REMOVE(&cpu->breakpoints, bp, entry);  in cpu_breakpoint_remove_by_ref()
440     trace_breakpoint_remove(cpu->cpu_index, bp->pc, bp->flags);  in cpu_breakpoint_remove_by_ref()
449     QTAILQ_FOREACH_SAFE(bp, &cpu->breakpoints, entry, next) {  in cpu_breakpoint_remove_all()
450         if (bp->flags & mask) {  in cpu_breakpoint_remove_all()