Re: [Qemu-devel] [Qemu-ppc] regression: target/ppc: convert VSX logical operations to vector operations broke X for ppc64le guest

[Laurent Vivier]

On 28/02/2019 17:59, Mark Cave-Ayland wrote:
> On 28/02/2019 08:39, Andrew Randrianasulu wrote:
> 
>>>> configure line:
>>>> setarch i686 ./configure --target-list=ppc64-softmmu
>>>>
>>>> launch line:
>>>> ppc64-softmmu/qemu-system-ppc64 -display
>>>> sdl,gl=on -hda /mnt/sdb1/PPC-img/alpine_disk.img
>>>>
>>>> where alpine_disk.img is HDD installed Alpine 3.7 for ppc64le with xfce4
>>>> desktop.
>>>
>>> AFAICT the vector instructions converted here are independent of endian, so
>>> I can't see why this patch on its own would have any effect.
>>>
>>> Maybe it could be because the "setarch i686" part forces use of some
>>> lesser-used 32-bit paths in the vector code - is this required? And do you
>>> see the same issue on a x86_64 build?
>>
>> I use 32-bit Slackware userland with x86_64 kerenl - so setarch prevent most 
>> of 
>> configures from detecting my arch wrongly.
>>
>> Yes, bug was and is present with qemu compiled for x86_64 (inside chroot).
>> I initially discovered it there, and after dropping -O3 and even 
>> march=native, 
>> and even disabling avx2 via configure switch - moved to bisect.
>>
>> https://lists.gnu.org/archive/html/qemu-devel/2019-02/msg06414.html
> 
> Can you upload your alpine_disk.img somewhere and then email me the link 
> off-list?
> I'll see if I can take a look when I get a spare moment.

I've also bisected to this commit for a problem with qemu-pp64le.

commit 7b8fe477e12b164dda97f79e27b55b805d90384f
Author: Richard Henderson <address@hidden>
Date:   Fri Feb 15 10:00:46 2019 +0000

    target/ppc: convert VSX logical operations to vector operations

    Signed-off-by: Richard Henderson <address@hidden>
    Acked-by: David Gibson <address@hidden>
    Message-Id: <address@hidden>
    Signed-off-by: David Gibson <address@hidden>


debian stretch ppc64el fails to build the well known hello.c example:
# $ cat /tmp/hello.c
#include <stdio.h>
int main(void)
{
    printf("Hello World!\n");
    return 0;
}
# cc -o /tmp/hello /tmp/hello.c
In file included from <command-line>:0:0:
/usr/include/stdc-predef.h:26:2: error: unknown type name '_STDC_'
    explicitly includes a system header.  GCC knows the name of this
  ^ ~~~~
/usr/include/stdc-predef.h:28:1: error: expected '=', ',', ';', 'asm' or
'__attribute__' before '_STDC_PREDEF_H'

 ^
/usr/include/stdc-predef.h:42:2: error: missing terminating ' character
 #endif
  ^~~~~
...