Re: [PATCH v4 7/8] docs/microvm.txt: document the new microvm machine type

[Sergio Lopez]

Gerd Hoffmann <address@hidden> writes:

>   Hi,
>
>> +microvm.kernel-cmdline=bool (Set off to disable adding virtio-mmio devices 
>> to the kernel cmdline)
>
> Hmm, is that the long-term plan?  IMO the virtio-mmio devices should be
> discoverable somehow.  ACPI, or device-tree, or fw_cfg, or ...

I'd say that depends on the machine type. ARM's virt and vexpress do
support virtio-mmio devices, adding them to a generated DTB.

For microvm that's simply not worth it. Fiddling with the command line
achieves the same result without any significant drawbacks, with less
code and less consumed cycles on both sides.

>> +As no current FW is able to boot from a block device using virtio-mmio
>> +as its transport,
>
> To fix that the firmware must be able to find the virtio-mmio devices.

No FW supports modern virtio-mmio transports anyway. And, from microvm's
perspective, there's little incentive to change this situation, given
that it's main use cases (serverless computing and VM-isolated
containers) will run with an external kernel.

Thanks,
Sergio.

signature.asc
Description: PGP signature