From 56c0269a9ec105d3848d9f900b5e38e6b35e2478 Mon Sep 17 00:00:00 2001 From: Pavel Dovgalyuk Date: Thu, 17 Sep 2015 19:23:59 +0300 Subject: cpu-exec: allow temporary disabling icount This patch is required for deterministic replay to generate an exception by trying executing an instruction without changing icount. It adds new flag to TB for disabling icount while translating it. Signed-off-by: Paolo Bonzini Signed-off-by: Pavel Dovgalyuk Message-Id: <20150917162359.8676.77011.stgit@PASHA-ISP.def.inno> Signed-off-by: Paolo Bonzini --- cpu-exec.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'cpu-exec.c') diff --git a/cpu-exec.c b/cpu-exec.c index 7eef0830fe..a1e3d58692 100644 --- a/cpu-exec.c +++ b/cpu-exec.c @@ -184,7 +184,7 @@ 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; @@ -194,7 +194,8 @@ static void cpu_exec_nocache(CPUState *cpu, int max_cycles, max_cycles = CF_COUNT_MASK; tb = tb_gen_code(cpu, orig_tb->pc, orig_tb->cs_base, orig_tb->flags, - max_cycles | CF_NOCACHE); + 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 */ @@ -519,7 +520,7 @@ 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; -- cgit v1.2.3 From 6f0609697f3670bf755a91477487507a8ffee471 Mon Sep 17 00:00:00 2001 From: Pavel Dovgalyuk Date: Thu, 17 Sep 2015 19:24:16 +0300 Subject: replay: interrupts and exceptions This patch includes modifications of common cpu files. All interrupts and exceptions occured during recording are written into the replay log. These events allow correct replaying the execution by kicking cpu thread when one of these events is found in the log. Signed-off-by: Pavel Dovgalyuk Message-Id: <20150917162416.8676.57647.stgit@PASHA-ISP.def.inno> Signed-off-by: Paolo Bonzini --- cpu-exec.c | 48 ++++++++++++++++++++++++++++++++++++++---------- 1 file changed, 38 insertions(+), 10 deletions(-) (limited to 'cpu-exec.c') diff --git a/cpu-exec.c b/cpu-exec.c index a1e3d58692..a57b388623 100644 --- a/cpu-exec.c +++ b/cpu-exec.c @@ -30,6 +30,7 @@ #if defined(TARGET_I386) && !defined(CONFIG_USER_ONLY) #include "hw/i386/apic.h" #endif +#include "sysemu/replay.h" /* -icount align implementation. */ @@ -346,21 +347,25 @@ int cpu_exec(CPUState *cpu) uintptr_t next_tb; SyncClocks sc; + /* 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) { + 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; atomic_mb_set(&tcg_current_cpu, cpu); rcu_read_lock(); @@ -402,10 +407,22 @@ 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 */ @@ -421,30 +438,40 @@ 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. */ @@ -455,7 +482,8 @@ 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); -- cgit v1.2.3