Re: [Qemu-devel] 32-bit “qemu-system-i386 -enable-kvm” segfaults on x86_64

[Ludovic Courtès]

"Dr. David Alan Gilbert" <address@hidden> skribis:

> * Ludovic Courtès (address@hidden) wrote:
>> Hi Daniel,
>> 
>> Thanks for the quick reply.
>> 
>> Daniel P. Berrangé <address@hidden> skribis:
>> 
>> > On Wed, Jul 04, 2018 at 02:34:07PM +0200, Ludovic Courtès wrote:
>> >> Hello,
>> >> 
>> >> (I’m reporting the issue here because for some reason the launchpad.net
>> >> login page redirects me to an “oops” page and fails to log me in.)
>> >> 
>> >> On a Linux 4.17 x86_64 host, “qemu-system-i386 -enable-kvm”, where
>> >> qemu-system-i386 is a 32-bit binary, crashes (it works fine without
>> >> ‘-enable-kvm’):
>> >> 
>> >> --8<---------------cut here---------------start------------->8---
>> >> $ uname -rm
>> >> 4.17.3-gnu x86_64
>> >> $ file 
>> >> /gnu/store/h22dc67wzkv0w2l3775f0xqkyr318x5j-qemu-minimal-2.12.0/bin/qemu-system-i386
>> >>  
>> >> /gnu/store/h22dc67wzkv0w2l3775f0xqkyr318x5j-qemu-minimal-2.12.0/bin/qemu-system-i386:
>> >>  ELF 32-bit LSB shared object, Intel 80386, version 1 (SYSV), dynamically 
>> >> linked, interpreter 
>> >> /gnu/store/4aka3nwppxf3z072l6vr8cxvwj3x5h9s-glibc-2.27/lib/ld-linux.so.2, 
>> >> for GNU/Linux 2.6.32, stripped
>> >
>> > It appears that not only are you using qemu-system-i386 on x86_64
>> > host, but this has actually also been built as a 32-bit ELF binary,
>> > so will be using the 32-bit compat syscalls. This is quite possibly
>> > relevant to any crash, so it would be useful to know if qemu-system-i386,
>> > when built as a 64-bit ELF binary works or fails.
>> 
>> The 64-bit qemu-system-i386 works fine.
>> 
>> > It appears you are using 2.12.0 release, so it is also helpful if
>> > you would try using current git master to see if it still reproduces.
>> 
>> Here’s what I get with today’s master (commit
>> 6d8ad1614e0c97c59a87e6c6208ebeb94e769149):
>
> If you do a dmesg after you get the seg fault do you see
> any unusual messages ?

Just this:

  qemu-system-i38[1762]: segfault at 14 ip 000000005675842e sp 00000000f621d000 
error 4 in qemu-system-i386[565e2000+b3d000]

Ludo’.