Re: [Qemu-devel] [PULL 00/10] target-arm queue

["Richard W.M. Jones" <rjones@redhat.com>]

On Sun, May 04, 2014 at 07:48:38PM +0100, Peter Maydell wrote:
> On 4 May 2014 19:30, Richard W.M. Jones <rjones@redhat.com> wrote:
> > I have real aarch64 hardware, and I'm trying to find a version of
> > qemu-system-aarch64 which will boot a KVM guest in some form.
> >
> > Upstream qemu fails with a bizarre thread-local storage problem (yes,
> > I've patched glibc to fix the makecontext problem).
> >
> > Is there a qemu tree I should be looking at?
> 
> Upstream is it. I haven't been testing it for a while though; it's possible
> it bitrotted while I wasn't looking.

OK, it might be a kernel problem then.

This was the issue I was having before:

/home/rjones/d/qemu/aarch64-softmmu/qemu-system-aarch64 \
    -global virtio-blk-device.scsi=off \
    -nodefconfig \
    -enable-fips \
    -nodefaults \
    -display none \
    -M virt \
    -machine accel=kvm:tcg \
    -m 500 \
    -no-reboot \
    -rtc driftfix=slew \
    -global kvm-pit.lost_tick_policy=discard \
    -kernel /home/rjones/d/libguestfs/tmp/.guestfs-1000/appliance.d/kernel \
    -initrd /home/rjones/d/libguestfs/tmp/.guestfs-1000/appliance.d/initrd \
    -device virtio-scsi-device,id=scsi \
    -drive file=/home/rjones/d/libguestfs/tmp/libguestfsHRi4Tt/scratch.1,cache=unsafe,format=raw,id=hd0,if=none \
    -device scsi-hd,drive=hd0 \
    -drive file=/home/rjones/d/libguestfs/tmp/.guestfs-1000/appliance.d/root,snapshot=on,id=appliance,cache=unsafe,if=none \
    -device scsi-hd,drive=appliance \
    -device virtio-serial-device \
    -serial stdio \
    -chardev socket,path=/home/rjones/d/libguestfs/tmp/libguestfsHRi4Tt/guestfsd.sock,id=channel0 \
    -device virtserialport,chardev=channel0,name=org.libguestfs.channel.0 \
    -append 'panic=1 console=ttyS0 udevtimeout=600 no_timer_check acpi=off printk.time=1 cgroup_disable=memory root=/dev/sdb selinux=0 guestfs_verbose=1 TERM=screen'
Could not access KVM kernel module: Permission denied
failed to initialize KVM: Permission denied
Back to tcg accelerator.
libguestfs: error: appliance closed the connection unexpectedly, see earlier error messages
libguestfs: child_cleanup: 0x3b5a1770: child process died
libguestfs: sending SIGTERM to process 12438
libguestfs: error: /home/rjones/d/qemu/aarch64-softmmu/qemu-system-aarch64 killed by signal 11 (Segmentation fault), see debug messages above

The stack trace in qemu when the segfault occurs is:

Program terminated with signal SIGSEGV, Segmentation fault.
#0  0x000002aae2f17394 in cpu_arm_exec (env=0x3ff8401eed0, 
    env@entry=0x2ab1c978440) at /home/rjones/d/qemu/cpu-exec.c:241
241         current_cpu = cpu;

(gdb) print tls__current_cpu 
Cannot find thread-local storage for LWP 12922, executable file /home/rjones/d/qemu/aarch64-softmmu/qemu-system-aarch64:
TLS not supported on this target

... and ^^^ that's the part that makes no sense to me.  TLS must
surely be supported, so there must be something odd about the
compile-time environment.

Linux ***.redhat.com 3.13.0-0.rc7.31.***.aarch64.debug #1 SMP Fri May 2 16:55:22 EDT 2014 aarch64 aarch64 aarch64 GNU/Linux

glibc-2.19.90-11.fc21.aarch64
gcc-4.9.0-1.fc21.aarch64

Rich.

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