Re: [Qemu-devel] qemu log function to print out the registers of the guest

[Max Filippov]

On Mon, Aug 27, 2012 at 8:15 PM, Steven <address@hidden> wrote:
>> Guest code is accessed at the translation time by C functions and
>> I guess there are other layers of address translation caching. I wouldn't
>> try to interpret these _cmmu printouts and would instead instrument
>> [cpu_]ld{{u,s}{b,w},l,q}_code macros.
> yes, you are right.
> Some ldub_code in x86 guest does not call __ldq_cmmu when the tlb hits.
> By the way, when I use your patch, I saw too many log event for the
> kernel data _mmu, ie., the addrs is
> 0x7fff ffff ffff. There are too many such mmu event that the user mode
> data can not be executed. So I have to  setup a condition like
>      if (addr < 0x8000 0000 0000)
>             fprintf(stderr, "%s: %08x\n", __func__, addr);
> Then my simple array access program can be finished.

You can also try to differentiate kernel/userspace by mmu_idx passed to
helpers.

> I am wondering whether you have met the similar problem or you have
> any suggestion on this.

I used simple samples (tests/tcg/xtensa testsuite), their memory access
pattern didn't deviate from what I expected.

> My final  goal is to obtain the memory access trace for a particular
> process in the guest, so your patch really helps, except for too many
> kernel _mmu events.

Wouldn't it be easier to use qemu-user for that?

-- 
Thanks.
-- Max