[gentoo-user] SOLVED: Gentoo as kvm guest with virtio not detecting vda device (Gentoo as kvm guest with virtio)

[hw]

Hi,

I found that I needed to enable VIRTIO_PCI_LEGACY for the guest kernel.
I've also set 'virtio_pci.force_legacy=1' as kernel command line option.

This was suggested here: https://bugs.archlinux.org/task/44573


hw wrote:
> Bill Kenworthy wrote:
>> On 10/03/16 01:56, Rich Freeman wrote:
>>> On Wed, Mar 9, 2016 at 12:41 PM, hw <hw@×××××.de> wrote:
>>>>
>>>> I'm stuck with 'Could not find the root block device
>>>> in UUID= ...' when trying to boot the guest.
>>>>
>>>> Is grub2 unable to work with virtio devices?
>>>>
>>>
>>> Are you sure that is a grub2 message?  It seems more likely that this
>>> is a message from the kernel (unless it is referring to the grub2 root
>>> - posting the entire error would probably help here, and I didn't
>>> realize grub2 even can find its root with a UUID assuming it actually
>>> can).  Does your kernel have virtio support enabled?  What initramfs
>>> are you using?  The problem could lie with either.  See if you can get
>>> the initramfs to give you a shell (usually this can be done with a
>>> kernel command line option) and see what block devices it can see (run
>>> blkid or such).
>>>
>>> If you're not using an initramfs then that is your problem.  You can't
>>> use UUID to reference your root if you aren't using an initramfs.
>>>
>>
>> I had to use this on grub install:
>>
>> grub2-install --target=i386-pc /dev/vda && \
>> grub2-mkconfig -o /boot/grub/grub.cfg
>>
>> It couldn't find the right module without the hint.
>
> That seems to work just fine:
>
>
> livecd linux # grub2-install /dev/vda
> Installing for i386-pc platform.
> installation beendet. Keine Fehler aufgetreten.
>
>
> Do you think it claims to have worked but actually didn't?
>
>