On Fri, Jan 30, 2015 at 06:15:21PM +0100, Kevin Wolf wrote:
> Am 29.01.2015 um 17:25 hat Kashyap Chamarthy geschrieben:
> > $ qemu-system-x86_64 \
> > -nographic \
> > -nodefconfig \
> > -nodefaults \
> > -m 2048 \
> > -device virtio-scsi-pci,id=scsi \
> > -device virtio-serial-pci \
> > -serial stdio \
> > -drive file=./overlay1.qcow2,format=qcow2,if=virtio,cache=writeback
> > Segmentation fault (core dumped)
> >
> >
> > On the shell where `qemu-nbd` is running, I notice this
> >
> > nbd.c:nbd_receive_request():L756: read failed
> >
> >
> > Haven't investigated further with GDB, thought I'd bring it up here
> > first.
> >
> >
> > Versions
> > --------
> >
> > $ rpm -q qemu; uname -r
> > qemu-2.1.2-7.fc21.x86_64
> > 3.17.8-300.fc21.x86_64
>
> Copying Stefan because he's the master of AIO contexts and it is
> bs->aio_context that becomes NULL. I couldn't see anything obvious.
>
>
> In the meantime, could you retest on git master?
Just tested from git, and I can still reproduce it.
That's the commit I'm at:
$ git describe
v2.2.0-682-g16017c4
Run the NBD server, from git:
$ /home/kashyapc/build/qemu/qemu-nbd -f qcow2 \
-p10809 ./f21vm.qcow2 -t
Create the overlay:
$ /home/kashyapc/build/qemu/qemu-img create \
-f qcow2 -F nbd -o backing_file=nbd://localhost overlay2-of-f21vm.qcow2
Segmentation fault (core dumped)
Creating the overlay from the git-compiled `qemu-img` binary fails.
So, let's create the overlay using the `qemu-img` binary from the system
(RPM version noted above) and boot the overlay from the just compiled
QEMU x86_64 binary from git, still core dumps:
$ /home/kashyapc/build/qemu/x86_64-softmmu/qemu-system-x86_64 \
-nographic \
-nodefconfig \
-nodefaults \
-m 2048 \
-device virtio-scsi-pci,id=scsi \
-device virtio-serial-pci \
-serial stdio \
-drive file=./overlay2-f21vm.qcow2,format=qcow2,if=virtio,cache=writeback
Segmentation fault (core dumped)
PS: I'm traveling, so I'll be a little slow to respond here, but can
provide more debugging info from the coredump of `qemu-img` binary as I
have access to a real computer.
--
/kashyap
