Re: [Qemu-devel] [PATCH v2 5/5] tcg: restrict i386 regs definitions

[Kamil Rytarowski]

On 12.09.2017 00:13, Philippe Mathieu-Daudé wrote:
> On 09/11/2017 06:44 PM, Kamil Rytarowski wrote:
>> On 11.09.2017 23:33, Philippe Mathieu-Daudé wrote:
>>> Signed-off-by: Philippe Mathieu-Daudé <address@hidden>
>>> ---
>>> cleaning while here :)
>>>
>>>   accel/tcg/user-exec.c | 18 +++++++++---------
>>>   1 file changed, 9 insertions(+), 9 deletions(-)
>>>
>>> diff --git a/accel/tcg/user-exec.c b/accel/tcg/user-exec.c
>>> index 2a975eaf69..484a3f5f8f 100644
>>> --- a/accel/tcg/user-exec.c
>>> +++ b/accel/tcg/user-exec.c
>>> @@ -25,15 +25,6 @@
>>>   #include "exec/cpu_ldst.h"
>>>   #include "translate-all.h"
>>>   -#undef EAX
>>> -#undef ECX
>>> -#undef EDX
>>> -#undef EBX
>>> -#undef ESP
>>> -#undef EBP
>>> -#undef ESI
>>> -#undef EDI
>>> -#undef EIP
>>>   #ifdef __linux__
>>>   #include <sys/ucontext.h>
>>>   #endif
>>> @@ -131,6 +122,15 @@ static inline int handle_cpu_signal(uintptr_t
>>> pc, unsigned long address,
>>>   }
>>>     #if defined(__i386__)
>>> +#undef EAX
>>> +#undef ECX
>>> +#undef EDX
>>> +#undef EBX
>>> +#undef ESP
>>> +#undef EBP
>>> +#undef ESI
>>> +#undef EDI
>>> +#undef EIP
>>>     #if defined(__NetBSD__)
>>>   #include <ucontext.h>
>>>
>>
>> Why to move under i386?
> 
> I tracked the origin of these #defines in op-i386.c (7bfdb6d18c7b) and
> thought the Exx naming was for i386 while the x86_64 uses the Rxx naming
> (RAX .. RIP) so you'd only have them on i386 arch.
> However it seems I didn't realize you can access x86_64 registers in
> 32-bit mode via the EAX .. EIP naming, as you see I'm not confident with
> this CISC arch :S
> 
> So I guess it's best to ignore this patch?
> 

A typical 64-bit x86_64 OS can run 32-bit programs and reuse x86 32-bit
headers.

>>
>> SmartOS pollutes namespace with these symbols on x86_64.
>>
> 
> you should provide some VM :P
> 

Hope to see it too.

> I plan to test this project soon:
> https://www.packer.io/docs/builders/qemu.html
> 
> Regards,
> 
> Phil.

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