Re: [Qemu-devel] 9p as rootfs

[Pradeep Kiruvale]

Hi Marcin,

Hope you have compiled the qemu with virtfs enabled.i.e --enable-virtfs

And the cli looks like this.  But I am working on x86 not ARM.

-fsdev local,id=root,path=${ROOTFS},security_model=none,writeout=immediate
-device virtio-9p-pci,fsdev=root,mount_tag=/dev/root

-Regards,
Pradeep


On 27 September 2016 at 21:33, mar.krzeminski <address@hidden>
wrote:

> So for some reason kernel expect that 9pfs channel will be named /dev/root
> (root= seem to be ignored).
> Working command line:
>
> Kernel: /root=/dev/root rootfstype=9p rootflags=trans=virtio rw/
> Qemu: /-device virtio-9p-device,fsdev=host_fs,mount_tag=/dev/root -fsdev
> local,id=host_fs,security_model=none,path=////work/rootfs/
> /
> Thanks,
> Marcin/
> /
> W dniu 23.09.2016 o 21:41, mar.krzeminski pisze:
>
> And most important, while mounting as roots, error is:
>>
>> [    1.086235] device: '9p-1': device_add
>> [    1.087859] 9pnet_virtio: no channels available
>> [    1.091619] device: '9p-1': device_unregister
>> [    1.092783] device: '9p-1': device_create_release
>> [    1.093534] VFS: Cannot open root device "host" or unknown-block(0,0):
>> error -2
>>
>> Thanks,
>> Marcin
>>
>> W dniu 23.09.2016 o 21:38, mar.krzeminski pisze:
>>
>>> Hello,
>>>
>>> I have a problem in my custom arm machine to use 9p fs as a rootfs.
>>>
>>> 9p command line i qemu:
>>>
>>> /-device virtio-9p-device,fsdev=host_fs,mount_tag=hostfs -fsdev
>>> local,id=host_fs,security_model=none,path=/work/rootfs/
>>>
>>> Kernel cmd line:
>>>
>>> /--append "root=hostfs rootfstype=9p rootflags=trans=virtio noinitrd
>>> console=ttyS3,115200"
>>>
>>> /Device tree entry:
>>>
>>> /        virtio: address@hidden {//
>>> //            compatible = "virtio,mmio";//
>>> //            reg = <0xff0a4000 0x200>;//
>>> //            interrupts = <0 72 1>;//
>>> //            status = "okay";//
>>> //        };
>>>
>>>
>>> / I can mount this fs from kernel using fstab entry:
>>> /hostfs               /mnt/host            9p trans=virtio          0  0
>>>
>>> /Do you have any idea what am I doing wrong?
>>>
>>> Thanks,
>>> Marcin/
>>> /
>>>
>>
>>
>