Re: [PATCH v6 00/17] Introduce SCMI transport based on VirtIO

From: Floris Westermann
Date: Wed Aug 11 2021 - 05:31:39 EST

Hi Cristian,

I am currently working on an interface for VMs to communicate their
performance requirements to the hosts by passing through cpu frequency

Your patch looks very interesting but I have some questions:

On Mon, Jul 12, 2021 at 03:18:16PM +0100, Cristian Marussi wrote:
> The series has been tested using an emulated fake SCMI device and also a
> proper SCP-fw stack running through QEMU vhost-users, with the SCMI stack
> compiled, in both cases, as builtin and as a loadable module, running tests
> against mocked SCMI Sensors using HWMON and IIO interfaces to check the
> functionality of notifications and sync/async commands.
> Virtio-scmi support has been exercised in the following testing scenario
> on a JUNO board:
> - normal sync/async command transfers
> - notifications
> - concurrent delivery of correlated response and delayed responses
> - out-of-order delivery of delayed responses before related responses
> - unexpected delayed response delivery for sync commands
> - late delivery of timed-out responses and delayed responses
> Some basic regression testing against mailbox transport has been performed
> for commands and notifications too.
> No sensible overhead in total handling time of commands and notifications
> has been observed, even though this series do indeed add a considerable
> amount of code to execute on TX path.
> More test and measurements could be needed in these regards.

Can you share any data and benchmarks using you fake SCMI device.
Also, could you provide the emulated device code so that the results can
be reproduced.