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 Claudio,
    Could you tell me what host and guest OS are you using? And the
hardware is 96board or other Hisilicon Server?
    I use SoftIron. 8 cores AArch64 servers.


On 5 August 2016 at 18:32, Claudio Fontana <address@hidden>
wrote:

> On 05.08.2016 12:27, Claudio Fontana wrote:
> > 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:
> >>> 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.
> >
> > We are using version=9p2000.L here with qemu-system-aarch64, and it
> works well.
> > We tested only on qemu-2.5 though.
>
> Forgot to mention though that we backported commit c8225aa1 "virtio-9p:
> use accessor to get thread_pool" though,
> as without it we have experienced crashes.
>
> Ciao, C.
>
>