On 02.04.19 11:34, Samuel Ortiz wrote: > On Tue, Apr 02, 2019 at 10:12:28AM +0200, Igor Mammedov wrote: >> On Tue, 2 Apr 2019 09:56:13 +0200 >> David Hildenbrand <david@xxxxxxxxxx> wrote: >> >>>>> >>>>> I guess there will be quite some issues to be sorted out. >>>>> >>>> >>>> That's what I'm getting from the several feedback I got so far. But the >>>> more fundamental question is about the need for it. If you think this >>>> goes in the right direction to make things more generic and >>>> architecture agnostic, it might be worth the effort of trying to design >>>> such solution. If instead you think this will be reinventing the wheel >>>> and will not benefit any use case, then let's not waste some time on >>>> this. >>>> >>> >>> I think, the general cpu hotplug/unplug infrastructure in QEMU is pretty >>> much generic. The only special case most probably is hotplugging >>> different topologies. But the general "device_add $MODEL-$ARCH-cpu, >>> id=$ID..." + device_del $ID is most probably easy to deal with by QEMU >>> users. >>> >>> The main issue I think really is different hot(un)plug support per >>> architecture. We heard that there might be a solution for s390x soon. I >>> wonder what about other architectures. >>> >>> Of course, if people want to scrap ACPI completely, then >> question is why one would want this and what we would be trying to achieve doing so? >> >> If ACPI is removed completely then one would need to provide >> an alternative means to describe various HW which is main purpose of ACPI >> ACPI bytecode methods is just a nice icing on top of that >> which helps to abstract drivers from HW/firmware. >> >> Idea to use non standard DT instead looks like a horrible >> alternative instead. > The idea is to run without ACPI or DT. The kernel does not need to be > custom built. A generic Linux kernel can easily boot without ACPI or DT, > or any kind of HW description. Firecracker is an obvious use case for > that where there really is no point in having a hw description when you > can simply use the kernel command line for describing a set of > statically defined and immutable resources. crosvm goes a little > further with a more dynamic device model, PCI based, and still without > ACPI or DT. Just wondering, what about things like NUMA or such? > > Cheers, > Samuel. -- Thanks, David / dhildenb
