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

[Max Filippov]

On Thu, Aug 16, 2012 at 9:29 PM, Steven <address@hidden> wrote:
> On Thu, Aug 16, 2012 at 1:00 PM, Max Filippov <address@hidden> wrote:
>> On Thu, Aug 16, 2012 at 8:36 PM, Steven <address@hidden> wrote:
>>> On Thu, Aug 16, 2012 at 4:02 AM, 陳韋任 (Wei-Ren Chen)
>>> <address@hidden> wrote:
>>>>> I would like to is there any function that could log the register
>>>>> content of the guest machine, like "info registers" in the qemu
>>>>> monitor mode.
>>>>
>>>>   Why not check how "info registes" be implemented in QEMU? ;)
>>>> I guess you just have to log env->regs or something like that.
>>> Thanks for pointing this out.
>>> I would like to get a trace of guest memory access. So I can not use
>>> "info registers".
>>> What I want to do is that when tcg fetches a load instruction at
>>> disas_insns(), the guest memory address should be calculated. For
>>
>> No, you don't want this, because the same translated code may be
>> invoked multiple times with different values in registers.
>>
>>> example, the tb has an instruction of mov 0x4(%ebx)  %eax.
>>> To calculate the address of 0x4(%ebx), I need to know the value of %ebx.
>>> Is this correct? Thanks.
>>
>> Why don't you just instrument actual memory access functions in
>> softmmu_template.h ?
> But this code only touches the s->pc. For registers in the load
> instruction, it won't generate the memory access code. So I need to
> add code to some function to get the guest memory address access.

Take a close look at

DATA_TYPE
glue(glue(glue(HELPER_PREFIX, ld), SUFFIX), MMUSUFFIX)(ENV_PARAM
                                                       target_ulong addr,
                                                       int mmu_idx)

and

void glue(glue(glue(HELPER_PREFIX, st), SUFFIX), MMUSUFFIX)(ENV_PARAM
                                                            target_ulong addr,
                                                            DATA_TYPE val,
                                                            int mmu_idx)

At runtime they get addr, this is the virtual address of the memory access.
This file is included several times to instantiate these functions for
different memory access types.
A set of macros manipulates access size and whether it is code or data access.

-- 
Thanks.
-- Max