Hi Edgar,

On 20 Mar 2025, at 22:13, Edgar E. Iglesias edgar.iglesias@amd.com wrote:

Hi all,

I was wondering if the virtio-msg demos we have for FFA work on Xen? I have some vague memory that they do.

I wonder if I can use the same lower-level virtio-msg-bus or ffa calls to move messages between a DomU/Linux and a QEMU backend in Dom0?

Can someone point me to the code? Or documentation?

Viresh pointed you to the current status.

To extend on his mail, i have to mention the caveat that currently we have no memory sharing support through FF-A so the PoC is using grant tables.

I am working on a PoC to enable memory sharing between VMs through FF-A and I hope to have something i can share next week.

This is awesome if you start looking at this as it will be an opportunity to look at how we "standardize" the interface between the linux kernel and the VMM (rust based one for viresh, qemu based one for you).

I think we need to keep in mind that there could multiple bus implementations in the linux kernel but at the end the VMM should not depend on which one is used so we must find a way to have a generic Virtio Bus Backend user interface suitable for all use cases which would mean: - discovery handling should be done in the bus driver: the VMM must provide the list of devices available to the bus driver (list of device IDs) and inform it when a device is added or removed - the bus driver should inform the VMM if the other side diseappeared

Main point being that bus messages (even if those are the one defined by the Virtio message generic spec) must be handled by the bus driver.

We will also need to come quickly to an agreement on the Version handling as i think we did over engineered it and we need to simplify (I will start a seperate thread on the subject in the ML today).

If you have questions or want to discuss your specific needs to not hesitate to ping me.

Cheers Bertrand

Thanks!

Best regards, Edgar _______________________________________________ Virtio-msg mailing list -- virtio-msg@lists.linaro.org To unsubscribe send an email to virtio-msg-leave@lists.linaro.org

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