usage of virtio-blk-device etc (microvm?)

[Michael Tokarev]

Hi!

I tried to run the microvm variant of qemu-system, and found out
there's very little information about it available.

In particular, I wasn't able to have a hdd in the virtual machine
using virtio-blk-device like this:

 -drive file=foo,if=none,id=drv -device virtio-blk-device,drive=drv

What modules/options are needed within linux guest to see such a
drive?  By loading just virtio-blk module (which loads all its
dependencies) the drive isn't becoming available, like it usually
happens after loading virtio-pci with the pci version of virtio-blk.

Also, is there a way to use virtio-blk-device with, say, q35 machine
type? That is, to have virtio-BUS too?

Thanks!