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

[Claudio Fontana <claudio.fontana@huawei.com>]

Hi,

On 05.08.2016 10:28, Daniel P. Berrange 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:
>> [root@sha-win-225 ~]# 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.

We are using version=9p2000.L here with qemu-system-aarch64, and it works well.
We tested only on qemu-2.5 though.

Ciao,

Claudio


> 
>>      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
> 


-- 
Claudio Fontana
Server Virtualization Architect
Huawei Technologies Duesseldorf GmbH
Riesstraße 25 - 80992 München