Re: 9p broken?

["Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>]

Avi Kivity <avi@redhat.com> writes:

> Having an annoying bug on i386 kvm I decided to debug it buy running an
> i386 guest on my x86_64 host, use 9p to access a guest image, and run it
> using nested kvm.
>
> However, 9p appears to be broken: first, the configure test fails (patch
> sent).  Second, while mount works, ls on the mount point causes qemu to
> crash with

I missed that you have already sent a patch for configure fix. That
looks better that what i sent. I will ack that patch 

>
> (gdb) bt
> #0  error_set (errp=0x7fffe95fb128, fmt=0x5555558d4568 "{ 'class':
> 'VirtFSFeatureBlocksMigration', 'data': { 'path': %s, 'tag': %s } }") at
> /home/tlv/akivity/qemu/error.c:32
> #1  0x000055555567cb06 in v9fs_attach (opaque=0x7fffe95e3020) at
> /home/tlv/akivity/qemu/hw/9pfs/virtio-9p.c:988
> #2  0x000055555561d19f in coroutine_trampoline (i0=1449767888, i1=21845)
> at /home/tlv/akivity/qemu/coroutine-ucontext.c:138
> #3  0x00007ffff5a93ef0 in ?? ()	from /lib64/libc.so.6
> #4  0x00007fffffffce00 in ?? ()
> #5  0x0000000000000000 in ?? (
>
> **errp already points to a VirtFSFeatureBlocksMigration error;
> v9fs_attach() has been called a second time (the first time,
> understandably, on mount; the second on ls).
>

Why are we calling attach a second time ?. I am also not able to reproduce this

root@qemu-img-64:~# mount -t 9p -otrans=virtio,version=9p2000.L v_tmp /mnt
root@qemu-img-64:~# ls /mnt/a.c
/mnt/a.c


> Command line:
>
> qemu-system-x86_64 -m 4G -smp 4 -drive
> file=/images/Fedora-i386.img,if=virtio,cache=none -cdrom
> /images/iso/bfo.iso -device virtio-9p-pci,fsdev=root,mount_tag=root
> -fsdev local,id=root,path=/,security_model=passthrough -enable-kvm -net
> nic,model=virtio,netdev=net -netdev user,id=net -monitor stdio -cpu host
>

-aneesh