This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
Home Products Support Community News


Re: [Xen-devel] Re: domU: 32-bit emulation seems to be broken

To: Sven Köhler <sven.koehler@xxxxxxxxx>
Subject: Re: [Xen-devel] Re: domU: 32-bit emulation seems to be broken
From: Jeremy Fitzhardinge <jeremy@xxxxxxxx>
Date: Sat, 14 Mar 2009 15:03:00 -0700
Cc: xen-devel@xxxxxxxxxxxxxxxxxxx, xen-users@xxxxxxxxxxxxxxxxxxx
Delivery-date: Sat, 14 Mar 2009 15:03:30 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <49BB6F4A.90000@xxxxxxxxx>
List-help: <mailto:xen-devel-request@lists.xensource.com?subject=help>
List-id: Xen developer discussion <xen-devel.lists.xensource.com>
List-post: <mailto:xen-devel@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
References: <gpe0vg$j67$1@xxxxxxxxxxxxx> <gpei6e$gcn$1@xxxxxxxxxxxxx> <49BAFC72.4040501@xxxxxxxx> <49BB0184.1020503@xxxxxxxx> <49BB6F4A.90000@xxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
User-agent: Thunderbird (X11/20090105)
Sven Köhler wrote:
Jeremy Fitzhardinge schrieb:
Jeremy Fitzhardinge wrote:
Sven Köhler wrote:
Also asking the devel-list for help:

Sven Köhler schrieb:

I cannot execute any 32-bit executables. Same problem with 2.6.29-rc7.

I compiled and linked them statically on another machine where they work
just fine! But inside the xen domU, they just segfault:

a.out[32093] general protection ip:f7f7042f sp:ffc6f2d4 error:0

Is this a knows problem? CONFIG_IA32_EMULATION is turned on!

Hm, it works for me. Can you give more detail about what you're trying to run, the kernel .config and the distro? dmesg output would have some clues too.

Oh, and what's the CPU?  AMD?

The host is running Xen version 3.3.0.
The host CPU is:

# cat /proc/cpuinfo
processor    : 0
vendor_id    : AuthenticAMD
cpu family    : 15
model        : 47
model name    : AMD Athlon(tm) 64 Processor 3800+
stepping    : 2
cpu MHz        : 2399.822
cache size    : 512 KB
fpu        : yes
fpu_exception    : yes
cpuid level    : 1
wp        : yes
flags : fpu de tsc msr pae cx8 apic mtrr cmov pat clflush mmx fxsr sse sse2 syscall nx mmxext fxsr_opt lm 3dnowext 3dnow pni lahf_lm
bogomips    : 4800.70
TLB size    : 1024 4K pages
clflush size    : 64
cache_alignment    : 64
address sizes    : 40 bits physical, 48 bits virtual
power management: ts fid vid ttp tm stc

The kernel is vanilla (except for the xen/blkfront: use blk_rq_map_sg to generate ring entries patch). The config of my is attached.

The program I'm trying to run is:
$ cat test.c
#include <stdio.h>

int main(void)
  printf("Hallo Welt!\n");
  return 0;

I compiled it with "gcc --static test.c" on other box where the program runs fine and copied the output to my domU. I checked with ldd, that it really isn't a dynamic executable.

The dmesg output on the domU is this mysterious:
a.out[32093] general protection ip:f7f7042f sp:ffc6f2d4 error:0

The line appears each time, that the program segfaults.

Has it ever worked? If so, what kernel version did it stop working at? Does it fail with all 32-bit executables or just your "hello world"?

Can you get a coredump from the fault and see what the faulting instruction was?


Xen-devel mailing list