On 27/11/2025 1:15 pm, Alejandro Vallejo wrote: >> Which raises the next question: Should we even allow a hypervisor to be built >> with X86_ENABLED_VENDORS == 0? > That's the most extreme case of "should we boot on a CPU known CPU vendor > that > has been compiled out?", the current code in the RFC uses the unknown vendor > as fallback. We could also panic. We could be trying to exercise the > "no assumptions about the vendor" paths. > > It's a policy decision for you (x86 mantainers) to take. I personally think > the > default path is silly in this day and age and we could get rid of it entirely. > Without it X86_ENABLED_VENDORS=0 would be indeed illegal. On that topic...
We allow compiling out both PV and HVM, so Randconfig can search for broken corners of the abstraction. The same principle applies here. For running such a hypervisor, I can't see anything that would fundamentally interfere with PV guests; PV guests are all architectural x86. I don't like there being an explicit Kconfig option for UNKNOWN. UNKNOWN should simply be "didn't match anything we compiled in". ~Andrew
