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-rw-r--r--accel/tcg/translate-all.c18
1 files changed, 9 insertions, 9 deletions
diff --git a/accel/tcg/translate-all.c b/accel/tcg/translate-all.c
index 464b3c3394..bbd919a393 100644
--- a/accel/tcg/translate-all.c
+++ b/accel/tcg/translate-all.c
@@ -2400,7 +2400,8 @@ void tb_check_watchpoint(CPUState *cpu, uintptr_t retaddr)
}
#ifndef CONFIG_USER_ONLY
-/* in deterministic execution mode, instructions doing device I/Os
+/*
+ * In deterministic execution mode, instructions doing device I/Os
* must be at the end of the TB.
*
* Called by softmmu_template.h, with iothread mutex not held.
@@ -2431,19 +2432,18 @@ void cpu_io_recompile(CPUState *cpu, uintptr_t retaddr)
n = 2;
}
- /* Generate a new TB executing the I/O insn. */
- cpu->cflags_next_tb = curr_cflags() | CF_LAST_IO | n;
+ /*
+ * Exit the loop and potentially generate a new TB executing the
+ * just the I/O insns. We also limit instrumentation to memory
+ * operations only (which execute after completion) so we don't
+ * double instrument the instruction.
+ */
+ cpu->cflags_next_tb = curr_cflags() | CF_MEMI_ONLY | CF_LAST_IO | n;
qemu_log_mask_and_addr(CPU_LOG_EXEC, tb->pc,
"cpu_io_recompile: rewound execution of TB to "
TARGET_FMT_lx "\n", tb->pc);
- /* TODO: If env->pc != tb->pc (i.e. the faulting instruction was not
- * the first in the TB) then we end up generating a whole new TB and
- * repeating the fault, which is horribly inefficient.
- * Better would be to execute just this insn uncached, or generate a
- * second new TB.
- */
cpu_loop_exit_noexc(cpu);
}