Re: [Qemu-arm] [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/
/