On Thu, Jul 25, 2024 at 02:50:50PM +0100, David Woodhouse wrote: > Even if the virtio-rtc specification were official today, and I was > able to expose it via PCI, I probably wouldn't do it that way. There's > just far more in virtio-rtc than we need; the simple shared memory > region is perfectly sufficient for most needs, and especially ours. I can't stop amazon from shipping whatever in its hypervisor, I'd just like to understand this better, if there is a use-case not addressed here then we can change virtio to address it. The rtc driver patch posted is 900 lines, yours is 700 lines, does not look like a big difference. As for using a memory region, this is valid, but maybe rtc should be changed to do exactly that? E.g. we can easily add a capability describing such a region. or put it in device config space. I mean yes, we can build a new transport for each specific need but in the end we'll get a ton of interfaces with unclear compatibility requirements. If effort is instead spent improving common interfaces, we get consistency and everyone benefits. That's why I'm trying to understand the need here. -- MST