Hi Viresh,
I'll try to respond to your first question: indirect messages require FF-A notifications, and Trusty does not support those either. The problem isn't Trusty specifically, but the layers between it and Linux: the hypervisor and SPMC. To be as specific as I can: Hafnium supports notifications, but others don't.
For now, we'll need to work around this in virtio-msg-ffa with direct messages and polling.
Andrei Homescu
On 18-02-25, 15:30, Andrei Homescu wrote:
Hi Viresh,
I'll try to respond to your first question: indirect messages require FF-A notifications, and Trusty does not support those either. The problem isn't Trusty specifically, but the layers between it and Linux: the hypervisor and SPMC. To be as specific as I can: Hafnium supports notifications, but others don't.
For now, we'll need to work around this in virtio-msg-ffa with direct messages and polling.
Thanks Andrei for explaining that.
Hi Andrei,
Just a confirmation for my understanding: Having to use polling due to notification support missing is a temporary hack and mid-term you will switch to indirect messages right ?
Cheers Bertrand
On 19 Feb 2025, at 00:30, Andrei Homescu ah@immunant.com wrote:
Hi Viresh,
I'll try to respond to your first question: indirect messages require FF-A notifications, and Trusty does not support those either. The problem isn't Trusty specifically, but the layers between it and Linux: the hypervisor and SPMC. To be as specific as I can: Hafnium supports notifications, but others don't.
For now, we'll need to work around this in virtio-msg-ffa with direct messages and polling.
Andrei Homescu
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
Yes, that is correct. As soon as Trusty can use indirect messages, we will switch.
On Mon, Feb 24, 2025, 4:23 PM Bertrand Marquis Bertrand.Marquis@arm.com wrote:
Hi Andrei,
Just a confirmation for my understanding: Having to use polling due to notification support missing is a temporary hack and mid-term you will switch to indirect messages right ?
Cheers Bertrand
On 19 Feb 2025, at 00:30, Andrei Homescu ah@immunant.com wrote:
Hi Viresh,
I'll try to respond to your first question: indirect messages require
FF-A notifications, and Trusty does not support those either.
The problem isn't Trusty specifically, but the layers between it and
Linux: the hypervisor and SPMC.
To be as specific as I can: Hafnium supports notifications, but others
don't.
For now, we'll need to work around this in virtio-msg-ffa with direct
messages and polling.
Andrei Homescu
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
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Andrei Homescu -
Bertrand Marquis -
Viresh Kumar