Philippe Mathieu-Daudé <phi...@linaro.org> writes: > (+Peter who has more experience on such design). > > On 29/4/24 13:32, Markus Armbruster wrote: >> Philippe Mathieu-Daudé <phi...@linaro.org> writes:
[...] >>> IMO to avoid any future ambiguity (in heterogeneous machines), this >>> command must take a QOM device path (or a list of) and only notify >>> those. >> >> Let's compare: >> >> • With QOM path: >> >> · You need to know the machine's RTC device(s). >> >> Unfortunately, this is bothersome, as the QOM path is not stable. > > But we'll need more of that with dynamic machines... I view /machine/unattached a technical debt (see "hate" right below). It saved us the trouble of coming up with sensible names for onboard devices. And now the interest is about to be due. >> For Q35, it's generally "/machine/unattached/device[N]/rtc", but N >> varies with configuration (TCG N=2, KVM N=3 for me), and it might >> vary with machine type version. That's because the machine code >> creates ICH9-LPC without a proper name. We do that a lot. I hate >> it. >> >> Likewise for i440FX with PIIX3 instead of ICH9-LPC. >> >> For isapc, it's /machine/unattached/device[3]. I suspect the 3 >> isn't reliable there, either. >> >> microvm doesn't seem to have an RTC by default. [...]
