Virtualization - Nov 2022 - [PATCH/RFC] virtio_test: A module for testing virtio via userspace

Hi,

The original email is from 2009, so I assume you don't have it in
your inboxes already. Here is the original email:

https://lore.kernel.org/all/200906190927.34831.borntraeger at de.ibm.com/
> This patch introduces a prototype for a virtio_test module. This module can
> be bound to any virtio device via sysfs bind/unbind feature, e.g:
> $ echo virtio1 > /sys/bus/virtio/drivers/virtio_rng/unbind
> $ modprobe virtio_test
>
> On probe this module registers to all virtqueues and creates a character
> device for every virtio device. (/dev/viotest<number>).
> The character device offers ioctls to allow a userspace application to
submit
> virtio operations like addbuf, kick and getbuf. It also offers ioctls to
get
> information about the device and to query the amount of occurred callbacks
(or
> wait synchronously on callbacks).
As far as I understand the test driver was never merged and I can't find
any similar testing drivers. I am looking for a test module that allows
to create a transient virtio device that can be used to activate a virtio
driver are communicate with it as if from the host.

Does such thing exist already?
Or how are virtio transports/drivers tested/fuzzed nowadays?

Thanks

Am 12.11.22 um 17:19 schrieb Dmitry Vyukov:
> Hi,
> 
> The original email is from 2009, so I assume you don't have it in
> your inboxes already. Here is the original email:
> 
> https://lore.kernel.org/all/200906190927.34831.borntraeger at de.ibm.com/
> 
>> This patch introduces a prototype for a virtio_test module. This module
can
>> be bound to any virtio device via sysfs bind/unbind feature, e.g:
>> $ echo virtio1 > /sys/bus/virtio/drivers/virtio_rng/unbind
>> $ modprobe virtio_test
>>
>> On probe this module registers to all virtqueues and creates a
character
>> device for every virtio device. (/dev/viotest<number>).
>> The character device offers ioctls to allow a userspace application to
submit
>> virtio operations like addbuf, kick and getbuf. It also offers ioctls
to get
>> information about the device and to query the amount of occurred
callbacks (or
>> wait synchronously on callbacks).
> 
> As far as I understand the test driver was never merged and I can't
find
> any similar testing drivers. I am looking for a test module that allows
> to create a transient virtio device that can be used to activate a virtio
> driver are communicate with it as if from the host.
> 
> Does such thing exist already?
> Or how are virtio transports/drivers tested/fuzzed nowadays?

Right, the driver was never merged.
Adding Michael as todays virtio maintainer for ideas how to proceed.

On Sat, Nov 12, 2022 at 05:19:42PM +0100, Dmitry Vyukov
wrote:
> I am looking for a test module that allows
> to create a transient virtio device that can be used to activate a virtio
> driver are communicate with it as if from the host.
> Does such thing exist already?
> Or how are virtio transports/drivers tested/fuzzed nowadays?
> 
> Thanks
Just coding it up in qemu is probably easiest.  This is how we test
most things.

-- 
MST