Re: [Qemu-devel] [PATCH qemu] loader: Trace loaded images

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

On 6/20/19 10:53 AM, Philippe Mathieu-Daudé wrote:
> On 6/20/19 7:50 AM, Alexey Kardashevskiy wrote:
>> On 17/06/2019 14:56, Philippe Mathieu-Daudé wrote:
>>> On 6/17/19 3:25 AM, Alexey Kardashevskiy wrote:
>>>> On 14/06/2019 19:33, Stefan Hajnoczi wrote:
>>>>> On Fri, Jun 14, 2019 at 10:13:04AM +1000, Alexey Kardashevskiy wrote:
>>>>>>
>>>>>>
>>>>>> On 13/06/2019 23:08, Philippe Mathieu-Daudé wrote:
>>>>>>> Hi Alexey,
>>>>>>>
>>>>>>> On 6/13/19 7:09 AM, Alexey Kardashevskiy wrote:
>>>>>>>> This adds a trace point which prints every loaded image. This includes
>>>>>>>> bios/firmware/kernel/initradmdisk/pcirom.
>>>>>>>>
>>>>>>>> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
>>>>>>>> ---
>>>>>>>>
>>>>>>>> The example for a pseries guest:
>>>>>>>>
>>>>>>>> loader_write_rom slof.bin: @0x0 size=0xe22e0 ROM=0
>>>>>>>> loader_write_rom phdr #0: /home/aik/t/vml4120le: @0x400000 size=0x13df000 ROM=0
>>>>>>>> loader_write_rom /home/aik/t/le.cpio: @0x1ad0000 size=0x9463a00 ROM=0
>>>>>>>
>>>>>>> I find the "ROM=0" part confuse, maybe you can change to "ROM:false".
>>>>>>
>>>>>> How? I mean I can do that in the code as rom->isrom?"true":"false" and
>>>>>> make trace point accept "%s" but it is quite ugly and others seem to
>>>>>> just use %d for bool.
>>>>>
>>>>> Yes, %d is the convention for bool.  Perhaps you can name it "is_rom"
>>>>> instead of "ROM".  That way the name communicates that this is a boolean
>>>>> value.
>>>>
>>>> It is quite obvious though that it is boolean even as "ROM" (what else
>>>> can that be realistically?) and there does not seem to be a convention
>>>> about xxx:N vs is_xxx:N. And personally I find longer lines worse for
>>>> limited width screens (I run multiple qemus in tiled tmux). Whose tree
>>>> is this going to? Let's ask that person :)
>>>
>>> Personally I find 'is_rom' clearer. I read 2 addresses, then my first
>>> reaction was to parse it as another address. But it is also true we now
>>> enforce traced hex values with '0x' prefix, so your 'ROM' is unlikely an
>>> address. Tiled tmux is an acceptable argument. Anyway you already got my
>>> R-b.
>>>
>>> Tree: the PPC tree is likely to get it merged quicker than the MISC tree.
>>
>>
>> There is nothing specific about PPC though so I guess it is the MISC
>> tree, who does maintain that?
> 
> Paolo, Cc'ing him.

Stefan sometime takes tracing patches, but this patch might also go via
Trivial@ (Cc'ed).