diff options
Diffstat (limited to 'qemu/cpu-exec.c')
| -rw-r--r-- | qemu/cpu-exec.c | 280 |
1 files changed, 151 insertions, 129 deletions
diff --git a/qemu/cpu-exec.c b/qemu/cpu-exec.c index 75694f3bb..bbfcbfb54 100644 --- a/qemu/cpu-exec.c +++ b/qemu/cpu-exec.c @@ -16,7 +16,7 @@ * 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" @@ -25,9 +25,13 @@ #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. */ @@ -128,57 +132,16 @@ static void init_delay_params(SyncClocks *sc, const CPUState *cpu) } #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; + 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)) { @@ -196,7 +159,7 @@ static inline tcg_target_ulong cpu_tb_exec(CPUState *cpu, uint8_t *tb_ptr) } #endif /* DEBUG_DISAS */ - cpu->can_do_io = 0; + cpu->can_do_io = !use_icount; next_tb = tcg_qemu_tb_exec(env, tb_ptr); cpu->can_do_io = 1; trace_exec_tb_exit((void *) (next_tb & ~TB_EXIT_MASK), @@ -209,6 +172,10 @@ static inline tcg_target_ulong cpu_tb_exec(CPUState *cpu, uint8_t *tb_ptr) */ CPUClass *cc = CPU_GET_CLASS(cpu); TranslationBlock *tb = (TranslationBlock *)(next_tb & ~TB_EXIT_MASK); + qemu_log_mask_and_addr(CPU_LOG_EXEC, itb->pc, + "Stopped execution of TB chain before %p [" + TARGET_FMT_lx "] %s\n", + itb->tc_ptr, itb->pc, lookup_symbol(itb->pc)); if (cc->synchronize_from_tb) { cc->synchronize_from_tb(cpu, tb); } else { @@ -228,35 +195,32 @@ static inline tcg_target_ulong cpu_tb_exec(CPUState *cpu, uint8_t *tb_ptr) /* 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; - target_ulong pc = orig_tb->pc; - target_ulong cs_base = orig_tb->cs_base; - uint64_t flags = orig_tb->flags; /* 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; - /* tb_gen_code can flush our orig_tb, invalidate it now */ - tb_phys_invalidate(orig_tb, -1); - tb = tb_gen_code(cpu, pc, cs_base, flags, - max_cycles | CF_NOCACHE); + tb = tb_gen_code(cpu, orig_tb->pc, orig_tb->cs_base, orig_tb->flags, + max_cycles | CF_NOCACHE + | (ignore_icount ? CF_IGNORE_ICOUNT : 0)); + tb->orig_tb = tcg_ctx.tb_ctx.tb_invalidated_flag ? NULL : orig_tb; cpu->current_tb = tb; /* execute the generated code */ trace_exec_tb_nocache(tb, tb->pc); - cpu_tb_exec(cpu, tb->tc_ptr); + cpu_tb_exec(cpu, tb); cpu->current_tb = NULL; tb_phys_invalidate(tb, -1); tb_free(tb); } -static TranslationBlock *tb_find_slow(CPUState *cpu, - target_ulong pc, - target_ulong cs_base, - uint64_t flags) +static TranslationBlock *tb_find_physical(CPUState *cpu, + target_ulong pc, + target_ulong cs_base, + uint64_t flags) { CPUArchState *env = (CPUArchState *)cpu->env_ptr; TranslationBlock *tb, **ptb1; @@ -273,8 +237,9 @@ static TranslationBlock *tb_find_slow(CPUState *cpu, ptb1 = &tcg_ctx.tb_ctx.tb_phys_hash[h]; for(;;) { tb = *ptb1; - if (!tb) - goto not_found; + if (!tb) { + return NULL; + } if (tb->pc == pc && tb->page_addr[0] == phys_page1 && tb->cs_base == cs_base && @@ -286,25 +251,59 @@ static TranslationBlock *tb_find_slow(CPUState *cpu, 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; + if (tb->page_addr[1] == phys_page2) { + break; + } } else { - goto found; + break; } } ptb1 = &tb->phys_hash_next; } - 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; + /* Move the TB to the head of the list */ + *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; + return tb; +} + +static TranslationBlock *tb_find_slow(CPUState *cpu, + target_ulong pc, + target_ulong cs_base, + uint64_t flags) +{ + TranslationBlock *tb; + + tb = tb_find_physical(cpu, pc, cs_base, flags); + if (tb) { + goto found; + } + +#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; @@ -345,8 +344,6 @@ static void cpu_handle_debug_exception(CPUState *cpu) /* main execution loop */ -volatile sig_atomic_t exit_request; - int cpu_exec(CPUState *cpu) { CPUClass *cc = CPU_GET_CLASS(cpu); @@ -356,34 +353,32 @@ int cpu_exec(CPUState *cpu) #endif int ret, interrupt_request; TranslationBlock *tb; - uint8_t *tc_ptr; uintptr_t next_tb; SyncClocks sc; - /* This must be volatile so it is not trashed by longjmp() */ - volatile bool have_tb_lock = false; + /* replay_interrupt may need current_cpu */ + current_cpu = cpu; if (cpu->halted) { +#if defined(TARGET_I386) && !defined(CONFIG_USER_ONLY) + if ((cpu->interrupt_request & CPU_INTERRUPT_POLL) + && replay_interrupt()) { + apic_poll_irq(x86_cpu->apic_state); + cpu_reset_interrupt(cpu, CPU_INTERRUPT_POLL); + } +#endif if (!cpu_has_work(cpu)) { + current_cpu = NULL; return EXCP_HALTED; } cpu->halted = 0; } - current_cpu = cpu; - - /* As long as current_cpu is null, up to the assignment just above, - * requests by other threads to exit the execution loop are expected to - * be issued using the exit_request global. We must make sure that our - * evaluation of the global value is performed past the current_cpu - * value transition point, which requires a memory barrier as well as - * an instruction scheduling constraint on modern architectures. */ - smp_mb(); - + 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; } @@ -421,10 +416,22 @@ int cpu_exec(CPUState *cpu) cpu->exception_index = -1; break; #else - cc->do_interrupt(cpu); - cpu->exception_index = -1; + if (replay_exception()) { + cc->do_interrupt(cpu); + cpu->exception_index = -1; + } else if (!replay_has_interrupt()) { + /* give a chance to iothread in replay mode */ + ret = EXCP_INTERRUPT; + break; + } #endif } + } else if (replay_has_exception() + && cpu->icount_decr.u16.low + cpu->icount_extra == 0) { + /* try to cause an exception pending in the log */ + cpu_exec_nocache(cpu, 1, tb_find_fast(cpu), true); + ret = -1; + break; } next_tb = 0; /* force lookup of first TB */ @@ -440,30 +447,40 @@ int cpu_exec(CPUState *cpu) cpu->exception_index = EXCP_DEBUG; cpu_loop_exit(cpu); } - if (interrupt_request & CPU_INTERRUPT_HALT) { + 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) - if (interrupt_request & CPU_INTERRUPT_INIT) { + else if (interrupt_request & CPU_INTERRUPT_INIT) { + 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 - if (interrupt_request & CPU_INTERRUPT_RESET) { + else if (interrupt_request & CPU_INTERRUPT_RESET) { + replay_interrupt(); cpu_reset(cpu); + cpu_loop_exit(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; + else { + replay_interrupt(); + 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. */ @@ -474,13 +491,13 @@ int cpu_exec(CPUState *cpu) next_tb = 0; } } - if (unlikely(cpu->exit_request)) { + if (unlikely(cpu->exit_request + || replay_has_interrupt())) { 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_lock(); 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 */ @@ -491,31 +508,21 @@ int cpu_exec(CPUState *cpu) 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) { + if (next_tb != 0 && tb->page_addr[1] == -1 + && !qemu_loglevel_mask(CPU_LOG_TB_NOCHAIN)) { 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); - - /* cpu_interrupt might be called while translating the - TB, but before it is linked into a potentially - infinite loop and becomes env->current_tb. Avoid - starting execution if there is a pending interrupt. */ - cpu->current_tb = tb; - barrier(); + tb_unlock(); if (likely(!cpu->exit_request)) { trace_exec_tb(tb, tb->pc); - tc_ptr = tb->tc_ptr; /* execute the generated code */ - next_tb = cpu_tb_exec(cpu, tc_ptr); + cpu->current_tb = tb; + next_tb = cpu_tb_exec(cpu, tb); + cpu->current_tb = NULL; switch (next_tb & TB_EXIT_MASK) { case TB_EXIT_REQUESTED: /* Something asked us to stop executing @@ -523,8 +530,12 @@ int cpu_exec(CPUState *cpu) * 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 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(); next_tb = 0; break; case TB_EXIT_ICOUNT_EXPIRED: @@ -541,7 +552,7 @@ int cpu_exec(CPUState *cpu) if (insns_left > 0) { /* Execute remaining instructions. */ tb = (TranslationBlock *)(next_tb & ~TB_EXIT_MASK); - cpu_exec_nocache(cpu, insns_left, tb); + cpu_exec_nocache(cpu, insns_left, tb, false); align_clocks(&sc, cpu); } cpu->exception_index = EXCP_INTERRUPT; @@ -554,7 +565,6 @@ int cpu_exec(CPUState *cpu) break; } } - cpu->current_tb = NULL; /* Try to align the host and virtual clocks if the guest is in advance */ align_clocks(&sc, cpu); @@ -562,19 +572,28 @@ int cpu_exec(CPUState *cpu) 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); - 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; - } +#else /* buggy compiler */ + /* Assert that the compiler does not smash local variables. */ + g_assert(cpu == current_cpu); + g_assert(cc == CPU_GET_CLASS(cpu)); +#ifdef TARGET_I386 + g_assert(x86_cpu == X86_CPU(cpu)); + g_assert(env == &x86_cpu->env); +#endif +#endif /* buggy compiler */ + cpu->can_do_io = 1; + tb_lock_reset(); } } /* for(;;) */ @@ -583,5 +602,8 @@ int cpu_exec(CPUState *cpu) /* fail safe : never use current_cpu outside cpu_exec() */ current_cpu = NULL; + + /* Does not need atomic_mb_set because a spurious wakeup is okay. */ + atomic_set(&tcg_current_cpu, NULL); return ret; } |