Re: [Qemu-devel] Tracing guest virtual addresses

[Lluís Vilanova]

Alex Bennée writes:

> Peter Maydell <address@hidden> writes:

>> On 20 June 2017 at 12:02, Lluís Vilanova <address@hidden> 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.


Cheers,
  Lluis