Alex Bennée writes: > Lluís Vilanova <vilan...@ac.upc.edu> writes:
>> Alex Bennée writes: >> >>> Peter Maydell <peter.mayd...@linaro.org> writes: >> >>>> On 20 June 2017 at 12:02, Lluís Vilanova <vilan...@ac.upc.edu> wrote: >>>>> Jayanto Minocha writes: >>>>>> But that is only used to instrument the cpu_ld/cpu_st macros, which is >>>>>> only >>>>>> called in the case of a tlb miss. >>>>> >>>>>> I've been going over the archives, and it looks like I need to instrument >>>>>> tcg_out_tlb_load. Am I on the right path ? >>>>> >>>>> That event should trace all guest memory accesses performed by the CPU. >>>>> If you >>>>> found any case where this does not hold, it is likely a bug and I'd >>>>> appreciate >>>>> it if you can point me to the smallest possible failing example. >>>> >>>> Does it catch memory accesses that are performed via helper functions, >>>> or only ones done by inline TCG code? >> >>> AFAICT it inserts a helper call on the TCG ld/st ops. I wonder why not >>> just ensure we always take the slow path and put the helpers in the >>> access functions there? You could even apply an address mask if you only >>> want to look at certain address ranges. >> >> It also catches accesses performed by helpers. > Don't helper accesses also pass through the SoftMMU? Or are we talking > about user-space access as well here? There's two places where memory access tracing is triggered: * tcg_gen_qemu_ld/st_... * ld/st templates (both softmmu and user) AFAIK, helpers use the ld/st templates to access guest memory. You can check for calls to trace_guest_mem_before_exec and trace_guest_mem_before_tcg. Thanks, Lluis
