Re: [Qemu-devel] [Help]: Does qemu-system-aarch64 support virtio-9p? I got a problem when remap host file to guest in AArch64.

[Kevin Zhao]

Hi Daniel && Peter && All,
     Thanks for your help. I've changed to 9p2000.u but also met the
problem. The qemu of booting the guests is here:
http://paste.openstack.org/show/550382/
     After booting *Debian 8* OS, enter into the guests  and run the
command( changed to 9p2000.u):
[image: Inline images 1]
*And you can see it has been blocked also :-)* .The dmesg info is here:
http://paste.openstack.org/show/550383/
In the last:
[  318.086744] FS-Cache: Loaded
[  318.089626] 9p: Installing v9fs 9p2000 file system support
[  318.089655] FS-Cache: Netfs '9p' registered for caching

 The guest kernel is 4.6.0-1-arm64 #1 SMP Debian 4.6.4-1 (2016-07-18)
aarch64 GNU/Linux
Guest qemu-system-aarch64: QEMU emulator version 2.6.0 (Debian 1:2.6+dfsg-3)
For Fedora 24, I find a bug here, related to this issue, Can't mount
virtio-9p fs at boot time
it is : https://bugzilla.redhat.com/show_bug.cgi?id=1184122

     It is a little werid of this problem, kindly need your help :-) Thanks~

On 5 August 2016 at 16:28, Daniel P. Berrange <address@hidden> wrote:

> On Fri, Aug 05, 2016 at 10:23:58AM +0800, Kevin Zhao wrote:
> > Hi All,
> >      I have a problem may about Qemu and kindly need your help. Does
> > qemu-system-aarch64 support virtio-9p ?
> >      Recently I have tried to use qemu remapped the file from host to
> > guest. As I know, Qemu has supported this so long as guest kernel has
> > support 9p(virtfs). Reference to this link:
> > http://wiki.qemu.org/Documentation/9psetup
> > Fedora 24 AArch64 kernel has supported this:
> > address@hidden ~]# lsmod | grep 9p
> > 9p                     56273  0
> > fscache                87449  1 9p
> > 9pnet_virtio            9122  0
> > 9pnet                  83564  2 9p,9pnet_virtio
> > virtio_ring            13866  5 virtio_net,virtio_pci,9pnet_
> > virtio,virtio_mmio,virtio_scsi
> > virtio                  9467  5 virtio_net,virtio_pci,9pnet_
> > virtio,virtio_mmio,virtio_scsi
> >
> >     Now I use virsh to launch the VM, and the corresponding qemu command
> I
> > have pasted here:
> > http://paste.openstack.org/show/549225/.
> >     You can see that:
> > * -fsdev
> > local,security_model=mapped,id=fsdev-fs0,path=/var/lib/
> libvirt/images/coreos
> > -device
> > virtio-9p-pci,id=fs0,fsdev=fsdev-fs0,mount_tag=share,bus=pci.2,addr=0x1*
> >      Here is the command that remapped the directory from host to guest.
> > After VM launched, I use the command to mount:
> > * mount -t 9p -o trans=virtio share /tmp/shared/
> > -oversion=9p2000.L,posixacl,cache=loose*
> > But mount command will be blocked and output nothing.
>
> Try using  version=9p2000.u instead - I've noticed other versions have
> been buggy in various kernel version/qemu version combinations. The
> 9p2000.u version is what i use in libvirt-sandobx and so I know it will
> work in general.
>
> >      The Qemu version is QEMU emulator version 2.5.0 (Debian
> > 1:2.5+dfsg-5ubuntu10.2). Besides test fedora24 guest, I have got the same
> > problem in Debian jessie.
> >       Kindly need your help~You will be really appreciated.
>
> Regards,
> Daniel
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