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 <pbonzini@redhat.com>

Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru>
Message-Id: <20150917162359.8676.77011.stgit@PASHA-ISP.def.inno>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 4 insertions, 3 deletions

diff --git a/cpu-exec.c b/cpu-exec.c
index 7eef083..a1e3d58 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;