* 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 "qemu/osdep.h"
#include "cpu.h"
#include "trace.h"
#include "disas/disas.h"
+#include "exec/exec-all.h"
#include "tcg.h"
#include "qemu/atomic.h"
#include "sysemu/qtest.h"
#include "qemu/timer.h"
#include "exec/address-spaces.h"
-#include "exec/memory-internal.h"
#include "qemu/rcu.h"
#include "exec/tb-hash.h"
+#include "exec/log.h"
+#if defined(TARGET_I386) && !defined(CONFIG_USER_ONLY)
+#include "hw/i386/apic.h"
+#endif
+#include "sysemu/replay.h"
/* -icount align implementation. */
}
#endif /* CONFIG USER ONLY */
-void cpu_loop_exit(CPUState *cpu)
-{
- cpu->current_tb = NULL;
- siglongjmp(cpu->jmp_env, 1);
-}
-
-/* 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_reload_memory_map(CPUState *cpu)
-{
- AddressSpaceDispatch *d;
-
- if (qemu_in_vcpu_thread()) {
- /* Do not let the guest prolong the critical section as much as it
- * as it desires.
- *
- * Currently, this is prevented by the I/O thread's periodinc kicking
- * of the VCPU thread (iothread_requesting_mutex, qemu_cpu_kick_thread)
- * but this will go away once TCG's execution moves out of the global
- * mutex.
- *
- * This pair matches cpu_exec's rcu_read_lock()/rcu_read_unlock(), which
- * only protects cpu->as->dispatch. Since we reload it below, we can
- * split the critical section.
- */
- rcu_read_unlock();
- rcu_read_lock();
- }
-
- /* The CPU and TLB are protected by the iothread lock. */
- d = atomic_rcu_read(&cpu->as->dispatch);
- cpu->memory_dispatch = d;
- tlb_flush(cpu, 1);
-}
-#endif
-
/* Execute a TB, and fix up the CPU state afterwards if necessary */
-static inline tcg_target_ulong cpu_tb_exec(CPUState *cpu, uint8_t *tb_ptr)
+static inline tcg_target_ulong cpu_tb_exec(CPUState *cpu, TranslationBlock *itb)
{
CPUArchState *env = cpu->env_ptr;
- uintptr_t next_tb;
+ uintptr_t ret;
+ TranslationBlock *last_tb;
+ int tb_exit;
+ uint8_t *tb_ptr = itb->tc_ptr;
+
+ qemu_log_mask_and_addr(CPU_LOG_EXEC, itb->pc,
+ "Trace %p [" TARGET_FMT_lx "] %s\n",
+ itb->tc_ptr, itb->pc, lookup_symbol(itb->pc));
#if defined(DEBUG_DISAS)
if (qemu_loglevel_mask(CPU_LOG_TB_CPU)) {
#endif /* DEBUG_DISAS */
cpu->can_do_io = !use_icount;
- next_tb = tcg_qemu_tb_exec(env, tb_ptr);
+ ret = tcg_qemu_tb_exec(env, tb_ptr);
cpu->can_do_io = 1;
- trace_exec_tb_exit((void *) (next_tb & ~TB_EXIT_MASK),
- next_tb & TB_EXIT_MASK);
+ last_tb = (TranslationBlock *)(ret & ~TB_EXIT_MASK);
+ tb_exit = ret & TB_EXIT_MASK;
+ trace_exec_tb_exit(last_tb, tb_exit);
- if ((next_tb & TB_EXIT_MASK) > TB_EXIT_IDX1) {
+ if (tb_exit > TB_EXIT_IDX1) {
/* We didn't start executing this TB (eg because the instruction
* counter hit zero); we must restore the guest PC to the address
* of the start of the TB.
*/
CPUClass *cc = CPU_GET_CLASS(cpu);
- TranslationBlock *tb = (TranslationBlock *)(next_tb & ~TB_EXIT_MASK);
+ qemu_log_mask_and_addr(CPU_LOG_EXEC, last_tb->pc,
+ "Stopped execution of TB chain before %p ["
+ TARGET_FMT_lx "] %s\n",
+ last_tb->tc_ptr, last_tb->pc,
+ lookup_symbol(last_tb->pc));
if (cc->synchronize_from_tb) {
- cc->synchronize_from_tb(cpu, tb);
+ cc->synchronize_from_tb(cpu, last_tb);
} else {
assert(cc->set_pc);
- cc->set_pc(cpu, tb->pc);
+ cc->set_pc(cpu, last_tb->pc);
}
}
- if ((next_tb & TB_EXIT_MASK) == TB_EXIT_REQUESTED) {
+ if (tb_exit == TB_EXIT_REQUESTED) {
/* We were asked to stop executing TBs (probably a pending
* interrupt. We've now stopped, so clear the flag.
*/
cpu->tcg_exit_req = 0;
}
- return next_tb;
+ return ret;
}
+#ifndef CONFIG_USER_ONLY
/* Execute the code without caching the generated code. An interpreter
could be used if available. */
static void cpu_exec_nocache(CPUState *cpu, int max_cycles,
- TranslationBlock *orig_tb)
+ TranslationBlock *orig_tb, bool ignore_icount)
{
TranslationBlock *tb;
+ bool old_tb_flushed;
/* Should never happen.
We only end up here when an existing TB is too long. */
if (max_cycles > CF_COUNT_MASK)
max_cycles = CF_COUNT_MASK;
+ old_tb_flushed = cpu->tb_flushed;
+ cpu->tb_flushed = false;
tb = tb_gen_code(cpu, orig_tb->pc, orig_tb->cs_base, orig_tb->flags,
- max_cycles | CF_NOCACHE);
- tb->orig_tb = tcg_ctx.tb_ctx.tb_invalidated_flag ? NULL : orig_tb;
- cpu->current_tb = tb;
+ max_cycles | CF_NOCACHE
+ | (ignore_icount ? CF_IGNORE_ICOUNT : 0));
+ tb->orig_tb = cpu->tb_flushed ? NULL : orig_tb;
+ cpu->tb_flushed |= old_tb_flushed;
/* execute the generated code */
trace_exec_tb_nocache(tb, tb->pc);
- cpu_tb_exec(cpu, tb->tc_ptr);
- cpu->current_tb = NULL;
+ cpu_tb_exec(cpu, tb);
tb_phys_invalidate(tb, -1);
tb_free(tb);
}
+#endif
+
+struct tb_desc {
+ target_ulong pc;
+ target_ulong cs_base;
+ CPUArchState *env;
+ tb_page_addr_t phys_page1;
+ uint32_t flags;
+};
+
+static bool tb_cmp(const void *p, const void *d)
+{
+ const TranslationBlock *tb = p;
+ const struct tb_desc *desc = d;
+
+ if (tb->pc == desc->pc &&
+ tb->page_addr[0] == desc->phys_page1 &&
+ tb->cs_base == desc->cs_base &&
+ tb->flags == desc->flags) {
+ /* check next page if needed */
+ if (tb->page_addr[1] == -1) {
+ return true;
+ } else {
+ tb_page_addr_t phys_page2;
+ target_ulong virt_page2;
+
+ virt_page2 = (desc->pc & TARGET_PAGE_MASK) + TARGET_PAGE_SIZE;
+ phys_page2 = get_page_addr_code(desc->env, virt_page2);
+ if (tb->page_addr[1] == phys_page2) {
+ return true;
+ }
+ }
+ }
+ return false;
+}
+
+static TranslationBlock *tb_find_physical(CPUState *cpu,
+ target_ulong pc,
+ target_ulong cs_base,
+ uint32_t flags)
+{
+ tb_page_addr_t phys_pc;
+ struct tb_desc desc;
+ uint32_t h;
+
+ desc.env = (CPUArchState *)cpu->env_ptr;
+ desc.cs_base = cs_base;
+ desc.flags = flags;
+ desc.pc = pc;
+ phys_pc = get_page_addr_code(desc.env, pc);
+ desc.phys_page1 = phys_pc & TARGET_PAGE_MASK;
+ h = tb_hash_func(phys_pc, pc, flags);
+ return qht_lookup(&tcg_ctx.tb_ctx.htable, tb_cmp, &desc, h);
+}
static TranslationBlock *tb_find_slow(CPUState *cpu,
target_ulong pc,
target_ulong cs_base,
- uint64_t flags)
+ uint32_t flags)
{
- CPUArchState *env = (CPUArchState *)cpu->env_ptr;
- TranslationBlock *tb, **ptb1;
- unsigned int h;
- tb_page_addr_t phys_pc, phys_page1;
- target_ulong virt_page2;
-
- tcg_ctx.tb_ctx.tb_invalidated_flag = 0;
-
- /* find translated block using physical mappings */
- phys_pc = get_page_addr_code(env, pc);
- phys_page1 = phys_pc & TARGET_PAGE_MASK;
- h = tb_phys_hash_func(phys_pc);
- ptb1 = &tcg_ctx.tb_ctx.tb_phys_hash[h];
- for(;;) {
- tb = *ptb1;
- if (!tb)
- goto not_found;
- if (tb->pc == pc &&
- tb->page_addr[0] == phys_page1 &&
- tb->cs_base == cs_base &&
- tb->flags == flags) {
- /* check next page if needed */
- if (tb->page_addr[1] != -1) {
- tb_page_addr_t phys_page2;
-
- virt_page2 = (pc & TARGET_PAGE_MASK) +
- TARGET_PAGE_SIZE;
- phys_page2 = get_page_addr_code(env, virt_page2);
- if (tb->page_addr[1] == phys_page2)
- goto found;
- } else {
- goto found;
- }
- }
- ptb1 = &tb->phys_hash_next;
+ TranslationBlock *tb;
+
+ tb = tb_find_physical(cpu, pc, cs_base, flags);
+ if (tb) {
+ goto found;
}
- not_found:
- /* if no translated code available, then translate it now */
- tb = tb_gen_code(cpu, pc, cs_base, flags, 0);
- found:
- /* Move the last found TB to the head of the list */
- if (likely(*ptb1)) {
- *ptb1 = tb->phys_hash_next;
- tb->phys_hash_next = tcg_ctx.tb_ctx.tb_phys_hash[h];
- tcg_ctx.tb_ctx.tb_phys_hash[h] = tb;
+#ifdef CONFIG_USER_ONLY
+ /* mmap_lock is needed by tb_gen_code, and mmap_lock must be
+ * taken outside tb_lock. Since we're momentarily dropping
+ * tb_lock, there's a chance that our desired tb has been
+ * translated.
+ */
+ tb_unlock();
+ mmap_lock();
+ tb_lock();
+ tb = tb_find_physical(cpu, pc, cs_base, flags);
+ if (tb) {
+ mmap_unlock();
+ goto found;
}
+#endif
+
+ /* if no translated code available, then translate it now */
+ tb = tb_gen_code(cpu, pc, cs_base, flags, 0);
+
+#ifdef CONFIG_USER_ONLY
+ mmap_unlock();
+#endif
+
+found:
/* we add the TB in the virtual pc hash table */
cpu->tb_jmp_cache[tb_jmp_cache_hash_func(pc)] = tb;
return tb;
}
-static inline TranslationBlock *tb_find_fast(CPUState *cpu)
+static inline TranslationBlock *tb_find_fast(CPUState *cpu,
+ TranslationBlock **last_tb,
+ int tb_exit)
{
CPUArchState *env = (CPUArchState *)cpu->env_ptr;
TranslationBlock *tb;
target_ulong cs_base, pc;
- int flags;
+ uint32_t flags;
/* we record a subset of the CPU state. It will
always be the same before a given translated block
is executed. */
cpu_get_tb_cpu_state(env, &pc, &cs_base, &flags);
+ tb_lock();
tb = cpu->tb_jmp_cache[tb_jmp_cache_hash_func(pc)];
if (unlikely(!tb || tb->pc != pc || tb->cs_base != cs_base ||
tb->flags != flags)) {
tb = tb_find_slow(cpu, pc, cs_base, flags);
}
+ if (cpu->tb_flushed) {
+ /* Ensure that no TB jump will be modified as the
+ * translation buffer has been flushed.
+ */
+ *last_tb = NULL;
+ cpu->tb_flushed = false;
+ }
+#ifndef CONFIG_USER_ONLY
+ /* We don't take care of direct jumps when address mapping changes in
+ * system emulation. So it's not safe to make a direct jump to a TB
+ * spanning two pages because the mapping for the second page can change.
+ */
+ if (tb->page_addr[1] != -1) {
+ *last_tb = NULL;
+ }
+#endif
+ /* See if we can patch the calling TB. */
+ if (*last_tb && !qemu_loglevel_mask(CPU_LOG_TB_NOCHAIN)) {
+ tb_add_jump(*last_tb, tb_exit, tb);
+ }
+ tb_unlock();
return tb;
}
-static void cpu_handle_debug_exception(CPUState *cpu)
+static inline bool cpu_handle_halt(CPUState *cpu)
+{
+ if (cpu->halted) {
+#if defined(TARGET_I386) && !defined(CONFIG_USER_ONLY)
+ if ((cpu->interrupt_request & CPU_INTERRUPT_POLL)
+ && replay_interrupt()) {
+ X86CPU *x86_cpu = X86_CPU(cpu);
+ apic_poll_irq(x86_cpu->apic_state);
+ cpu_reset_interrupt(cpu, CPU_INTERRUPT_POLL);
+ }
+#endif
+ if (!cpu_has_work(cpu)) {
+ current_cpu = NULL;
+ return true;
+ }
+
+ cpu->halted = 0;
+ }
+
+ return false;
+}
+
+static inline void cpu_handle_debug_exception(CPUState *cpu)
{
CPUClass *cc = CPU_GET_CLASS(cpu);
CPUWatchpoint *wp;
cc->debug_excp_handler(cpu);
}
-/* main execution loop */
+static inline bool cpu_handle_exception(CPUState *cpu, int *ret)
+{
+ if (cpu->exception_index >= 0) {
+ if (cpu->exception_index >= EXCP_INTERRUPT) {
+ /* exit request from the cpu execution loop */
+ *ret = cpu->exception_index;
+ if (*ret == EXCP_DEBUG) {
+ cpu_handle_debug_exception(cpu);
+ }
+ cpu->exception_index = -1;
+ return true;
+ } else {
+#if defined(CONFIG_USER_ONLY)
+ /* if user mode only, we simulate a fake exception
+ which will be handled outside the cpu execution
+ loop */
+#if defined(TARGET_I386)
+ CPUClass *cc = CPU_GET_CLASS(cpu);
+ cc->do_interrupt(cpu);
+#endif
+ *ret = cpu->exception_index;
+ cpu->exception_index = -1;
+ return true;
+#else
+ if (replay_exception()) {
+ CPUClass *cc = CPU_GET_CLASS(cpu);
+ cc->do_interrupt(cpu);
+ cpu->exception_index = -1;
+ } else if (!replay_has_interrupt()) {
+ /* give a chance to iothread in replay mode */
+ *ret = EXCP_INTERRUPT;
+ return true;
+ }
+#endif
+ }
+#ifndef CONFIG_USER_ONLY
+ } else if (replay_has_exception()
+ && cpu->icount_decr.u16.low + cpu->icount_extra == 0) {
+ /* try to cause an exception pending in the log */
+ TranslationBlock *last_tb = NULL; /* Avoid chaining TBs */
+ cpu_exec_nocache(cpu, 1, tb_find_fast(cpu, &last_tb, 0), true);
+ *ret = -1;
+ return true;
+#endif
+ }
-volatile sig_atomic_t exit_request;
-CPUState *tcg_current_cpu;
+ return false;
+}
-int cpu_exec(CPUState *cpu)
+static inline void cpu_handle_interrupt(CPUState *cpu,
+ TranslationBlock **last_tb)
{
CPUClass *cc = CPU_GET_CLASS(cpu);
-#ifdef TARGET_I386
- X86CPU *x86_cpu = X86_CPU(cpu);
- CPUArchState *env = &x86_cpu->env;
+ int interrupt_request = cpu->interrupt_request;
+
+ if (unlikely(interrupt_request)) {
+ if (unlikely(cpu->singlestep_enabled & SSTEP_NOIRQ)) {
+ /* Mask out external interrupts for this step. */
+ interrupt_request &= ~CPU_INTERRUPT_SSTEP_MASK;
+ }
+ if (interrupt_request & CPU_INTERRUPT_DEBUG) {
+ cpu->interrupt_request &= ~CPU_INTERRUPT_DEBUG;
+ cpu->exception_index = EXCP_DEBUG;
+ cpu_loop_exit(cpu);
+ }
+ if (replay_mode == REPLAY_MODE_PLAY && !replay_has_interrupt()) {
+ /* Do nothing */
+ } else if (interrupt_request & CPU_INTERRUPT_HALT) {
+ replay_interrupt();
+ cpu->interrupt_request &= ~CPU_INTERRUPT_HALT;
+ cpu->halted = 1;
+ cpu->exception_index = EXCP_HLT;
+ cpu_loop_exit(cpu);
+ }
+#if defined(TARGET_I386)
+ else if (interrupt_request & CPU_INTERRUPT_INIT) {
+ X86CPU *x86_cpu = X86_CPU(cpu);
+ CPUArchState *env = &x86_cpu->env;
+ replay_interrupt();
+ cpu_svm_check_intercept_param(env, SVM_EXIT_INIT, 0);
+ do_cpu_init(x86_cpu);
+ cpu->exception_index = EXCP_HALTED;
+ cpu_loop_exit(cpu);
+ }
+#else
+ else if (interrupt_request & CPU_INTERRUPT_RESET) {
+ replay_interrupt();
+ cpu_reset(cpu);
+ cpu_loop_exit(cpu);
+ }
#endif
- int ret, interrupt_request;
- TranslationBlock *tb;
- uint8_t *tc_ptr;
- uintptr_t next_tb;
- SyncClocks sc;
+ /* The target hook has 3 exit conditions:
+ False when the interrupt isn't processed,
+ True when it is, and we should restart on a new TB,
+ and via longjmp via cpu_loop_exit. */
+ else {
+ replay_interrupt();
+ if (cc->cpu_exec_interrupt(cpu, interrupt_request)) {
+ *last_tb = NULL;
+ }
+ /* The target hook may have updated the 'cpu->interrupt_request';
+ * reload the 'interrupt_request' value */
+ interrupt_request = cpu->interrupt_request;
+ }
+ if (interrupt_request & CPU_INTERRUPT_EXITTB) {
+ cpu->interrupt_request &= ~CPU_INTERRUPT_EXITTB;
+ /* ensure that no TB jump will be modified as
+ the program flow was changed */
+ *last_tb = NULL;
+ }
+ }
+ if (unlikely(cpu->exit_request || replay_has_interrupt())) {
+ cpu->exit_request = 0;
+ cpu->exception_index = EXCP_INTERRUPT;
+ cpu_loop_exit(cpu);
+ }
+}
- /* This must be volatile so it is not trashed by longjmp() */
- volatile bool have_tb_lock = false;
+static inline void cpu_loop_exec_tb(CPUState *cpu, TranslationBlock *tb,
+ TranslationBlock **last_tb, int *tb_exit,
+ SyncClocks *sc)
+{
+ uintptr_t ret;
- if (cpu->halted) {
- if (!cpu_has_work(cpu)) {
- return EXCP_HALTED;
- }
+ if (unlikely(cpu->exit_request)) {
+ return;
+ }
- cpu->halted = 0;
+ trace_exec_tb(tb, tb->pc);
+ ret = cpu_tb_exec(cpu, tb);
+ *last_tb = (TranslationBlock *)(ret & ~TB_EXIT_MASK);
+ *tb_exit = ret & TB_EXIT_MASK;
+ switch (*tb_exit) {
+ case TB_EXIT_REQUESTED:
+ /* Something asked us to stop executing
+ * chained TBs; just continue round the main
+ * loop. Whatever requested the exit will also
+ * have set something else (eg exit_request or
+ * interrupt_request) which we will handle
+ * next time around the loop. But we need to
+ * ensure the tcg_exit_req read in generated code
+ * comes before the next read of cpu->exit_request
+ * or cpu->interrupt_request.
+ */
+ smp_rmb();
+ *last_tb = NULL;
+ break;
+ case TB_EXIT_ICOUNT_EXPIRED:
+ {
+ /* Instruction counter expired. */
+#ifdef CONFIG_USER_ONLY
+ abort();
+#else
+ int insns_left = cpu->icount_decr.u32;
+ if (cpu->icount_extra && insns_left >= 0) {
+ /* Refill decrementer and continue execution. */
+ cpu->icount_extra += insns_left;
+ insns_left = MIN(0xffff, cpu->icount_extra);
+ cpu->icount_extra -= insns_left;
+ cpu->icount_decr.u16.low = insns_left;
+ } else {
+ if (insns_left > 0) {
+ /* Execute remaining instructions. */
+ cpu_exec_nocache(cpu, insns_left, *last_tb, false);
+ align_clocks(sc, cpu);
+ }
+ cpu->exception_index = EXCP_INTERRUPT;
+ *last_tb = NULL;
+ cpu_loop_exit(cpu);
+ }
+ break;
+#endif
+ }
+ default:
+ break;
}
+}
+
+/* main execution loop */
+
+int cpu_exec(CPUState *cpu)
+{
+ CPUClass *cc = CPU_GET_CLASS(cpu);
+ int ret;
+ SyncClocks sc;
+ /* replay_interrupt may need current_cpu */
current_cpu = cpu;
+
+ if (cpu_handle_halt(cpu)) {
+ return EXCP_HALTED;
+ }
+
atomic_mb_set(&tcg_current_cpu, cpu);
rcu_read_lock();
- if (unlikely(exit_request)) {
+ if (unlikely(atomic_mb_read(&exit_request))) {
cpu->exit_request = 1;
}
*/
init_delay_params(&sc, cpu);
- /* prepare setjmp context for exception handling */
for(;;) {
+ /* prepare setjmp context for exception handling */
if (sigsetjmp(cpu->jmp_env, 0) == 0) {
+ TranslationBlock *tb, *last_tb = NULL;
+ int tb_exit = 0;
+
/* if an exception is pending, we execute it here */
- if (cpu->exception_index >= 0) {
- if (cpu->exception_index >= EXCP_INTERRUPT) {
- /* exit request from the cpu execution loop */
- ret = cpu->exception_index;
- if (ret == EXCP_DEBUG) {
- cpu_handle_debug_exception(cpu);
- }
- cpu->exception_index = -1;
- break;
- } else {
-#if defined(CONFIG_USER_ONLY)
- /* if user mode only, we simulate a fake exception
- which will be handled outside the cpu execution
- loop */
-#if defined(TARGET_I386)
- cc->do_interrupt(cpu);
-#endif
- ret = cpu->exception_index;
- cpu->exception_index = -1;
- break;
-#else
- cc->do_interrupt(cpu);
- cpu->exception_index = -1;
-#endif
- }
+ if (cpu_handle_exception(cpu, &ret)) {
+ break;
}
- next_tb = 0; /* force lookup of first TB */
+ cpu->tb_flushed = false; /* reset before first TB lookup */
for(;;) {
- interrupt_request = cpu->interrupt_request;
- if (unlikely(interrupt_request)) {
- if (unlikely(cpu->singlestep_enabled & SSTEP_NOIRQ)) {
- /* Mask out external interrupts for this step. */
- interrupt_request &= ~CPU_INTERRUPT_SSTEP_MASK;
- }
- if (interrupt_request & CPU_INTERRUPT_DEBUG) {
- cpu->interrupt_request &= ~CPU_INTERRUPT_DEBUG;
- cpu->exception_index = EXCP_DEBUG;
- cpu_loop_exit(cpu);
- }
- if (interrupt_request & CPU_INTERRUPT_HALT) {
- cpu->interrupt_request &= ~CPU_INTERRUPT_HALT;
- cpu->halted = 1;
- cpu->exception_index = EXCP_HLT;
- cpu_loop_exit(cpu);
- }
-#if defined(TARGET_I386)
- if (interrupt_request & CPU_INTERRUPT_INIT) {
- cpu_svm_check_intercept_param(env, SVM_EXIT_INIT, 0);
- do_cpu_init(x86_cpu);
- cpu->exception_index = EXCP_HALTED;
- cpu_loop_exit(cpu);
- }
-#else
- if (interrupt_request & CPU_INTERRUPT_RESET) {
- cpu_reset(cpu);
- }
-#endif
- /* The target hook has 3 exit conditions:
- False when the interrupt isn't processed,
- True when it is, and we should restart on a new TB,
- and via longjmp via cpu_loop_exit. */
- if (cc->cpu_exec_interrupt(cpu, interrupt_request)) {
- next_tb = 0;
- }
- /* Don't use the cached interrupt_request value,
- do_interrupt may have updated the EXITTB flag. */
- if (cpu->interrupt_request & CPU_INTERRUPT_EXITTB) {
- cpu->interrupt_request &= ~CPU_INTERRUPT_EXITTB;
- /* ensure that no TB jump will be modified as
- the program flow was changed */
- next_tb = 0;
- }
- }
- if (unlikely(cpu->exit_request)) {
- cpu->exit_request = 0;
- cpu->exception_index = EXCP_INTERRUPT;
- cpu_loop_exit(cpu);
- }
- spin_lock(&tcg_ctx.tb_ctx.tb_lock);
- have_tb_lock = true;
- tb = tb_find_fast(cpu);
- /* Note: we do it here to avoid a gcc bug on Mac OS X when
- doing it in tb_find_slow */
- if (tcg_ctx.tb_ctx.tb_invalidated_flag) {
- /* as some TB could have been invalidated because
- of memory exceptions while generating the code, we
- must recompute the hash index here */
- next_tb = 0;
- tcg_ctx.tb_ctx.tb_invalidated_flag = 0;
- }
- if (qemu_loglevel_mask(CPU_LOG_EXEC)) {
- qemu_log("Trace %p [" TARGET_FMT_lx "] %s\n",
- tb->tc_ptr, tb->pc, lookup_symbol(tb->pc));
- }
- /* see if we can patch the calling TB. When the TB
- spans two pages, we cannot safely do a direct
- jump. */
- if (next_tb != 0 && tb->page_addr[1] == -1) {
- tb_add_jump((TranslationBlock *)(next_tb & ~TB_EXIT_MASK),
- next_tb & TB_EXIT_MASK, tb);
- }
- have_tb_lock = false;
- spin_unlock(&tcg_ctx.tb_ctx.tb_lock);
- if (likely(!cpu->exit_request)) {
- trace_exec_tb(tb, tb->pc);
- tc_ptr = tb->tc_ptr;
- /* execute the generated code */
- cpu->current_tb = tb;
- next_tb = cpu_tb_exec(cpu, tc_ptr);
- cpu->current_tb = NULL;
- switch (next_tb & TB_EXIT_MASK) {
- case TB_EXIT_REQUESTED:
- /* Something asked us to stop executing
- * chained TBs; just continue round the main
- * loop. Whatever requested the exit will also
- * have set something else (eg exit_request or
- * interrupt_request) which we will handle
- * next time around the loop.
- */
- next_tb = 0;
- break;
- case TB_EXIT_ICOUNT_EXPIRED:
- {
- /* Instruction counter expired. */
- int insns_left = cpu->icount_decr.u32;
- if (cpu->icount_extra && insns_left >= 0) {
- /* Refill decrementer and continue execution. */
- cpu->icount_extra += insns_left;
- insns_left = MIN(0xffff, cpu->icount_extra);
- cpu->icount_extra -= insns_left;
- cpu->icount_decr.u16.low = insns_left;
- } else {
- if (insns_left > 0) {
- /* Execute remaining instructions. */
- tb = (TranslationBlock *)(next_tb & ~TB_EXIT_MASK);
- cpu_exec_nocache(cpu, insns_left, tb);
- align_clocks(&sc, cpu);
- }
- cpu->exception_index = EXCP_INTERRUPT;
- next_tb = 0;
- cpu_loop_exit(cpu);
- }
- break;
- }
- default:
- break;
- }
- }
+ cpu_handle_interrupt(cpu, &last_tb);
+ tb = tb_find_fast(cpu, &last_tb, tb_exit);
+ cpu_loop_exec_tb(cpu, tb, &last_tb, &tb_exit, &sc);
/* Try to align the host and virtual clocks
if the guest is in advance */
align_clocks(&sc, cpu);
- /* reset soft MMU for next block (it can currently
- only be set by a memory fault) */
} /* for(;;) */
} else {
- /* Reload env after longjmp - the compiler may have smashed all
- * local variables as longjmp is marked 'noreturn'. */
+#if defined(__clang__) || !QEMU_GNUC_PREREQ(4, 6)
+ /* Some compilers wrongly smash all local variables after
+ * siglongjmp. There were bug reports for gcc 4.5.0 and clang.
+ * Reload essential local variables here for those compilers.
+ * Newer versions of gcc would complain about this code (-Wclobbered). */
cpu = current_cpu;
cc = CPU_GET_CLASS(cpu);
+#else /* buggy compiler */
+ /* Assert that the compiler does not smash local variables. */
+ g_assert(cpu == current_cpu);
+ g_assert(cc == CPU_GET_CLASS(cpu));
+#endif /* buggy compiler */
cpu->can_do_io = 1;
-#ifdef TARGET_I386
- x86_cpu = X86_CPU(cpu);
- env = &x86_cpu->env;
-#endif
- if (have_tb_lock) {
- spin_unlock(&tcg_ctx.tb_ctx.tb_lock);
- have_tb_lock = false;
- }
+ tb_lock_reset();
}
} /* for(;;) */
projects / mirror_qemu.git / blobdiff