Re: [Qemu-devel] Using virtio-mmio

["Richard W.M. Jones" <rjones@redhat.com>]

On Wed, Jul 31, 2013 at 11:01:11PM +0100, Peter Maydell wrote:
> On 31 July 2013 22:56, Richard W.M. Jones <rjones@redhat.com> wrote:
> > It's quite exciting the virtio-mmio made it into qemu.  Are extra
> > guest kernel components needed too? (I'm using 3.9.9-302.fc19.armv7hl
> > but could try a later kernel)
> 
> I think you're OK there, the support's been in the kernel for
> much longer than it's been in QEMU.
> 
> > Anyway, I tried to get it to work, but can't quite work out the qemu
> > command line.  So far I have:
> >
> > $ ~/d/qemu/arm-softmmu/qemu-system-arm -M vexpress-a15 -cpu cortex-a15 \
> >     -nographic -kernel kernel -initrd initrd \
> >     -drive file=root,if=virtio \
> >     -append "root=/dev/vda"
> > qemu-system-arm: -drive file=root,if=virtio: No 'PCI' bus found for device 'virtio-blk-pci'
> 
> You need to specify things longhand with the virtio-blk-device etc
> devices, because the shortcuts all assume virtio is PCI. So in
> this case:
> 
>    -drive if=none,file=root,id=foo \
>    -device virtio-blk-device,drive=foo

Thanks.  For the record, here is the final command line that boots as
far as the kernel [I'm still working on my initrd ..]:

~/d/qemu/arm-softmmu/qemu-system-arm \
  -m 512 -M vexpress-a9 -machine kernel_irqchip=on \
  -kernel kernel -initrd initrd \
  -drive if=none,file=root,id=foo -device virtio-blk-device,drive=foo \
  -append "root=/dev/vda console=ttyAMA0 rootwait earlyprintk debug" \
  -serial stdio

Rich.

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