Andrew Melnichenko <and...@daynix.com> writes: > Hi, > Yes, the stamp check was added. > So the qemu emulator should return a suitable RSS BPF helper or nothing. > Each qemu emulator may have a different helper that suits it. > So, the idea is to ask for the helper from qemu.
Please answer the question below. > > On Tue, Aug 24, 2021 at 9:41 AM Markus Armbruster <arm...@redhat.com> wrote: > >> Andrew Melnichenko <and...@daynix.com> writes: >> >> > Hi, >> > >> >> The helper may or may not be installed at the path compiled into QEMU. >> >> >> > Yes, so the helper will not be called - QEMU will try to initiate eBPF >> RSS >> > or use "in-qemu" RSS. >> >> My point is: the proposed command's mission is to help the management >> application run the right helper. However, its advice is *unreliable*. >> It may point to the wrong helper, or to nothing at all. The right >> helper may still exist elsewhere. >> >> I suspect you're trying to address the problem at the wrong level. >> >> Similar versioning issues exist with other helpers. We've been doing >> fine without QEMU providing unreliable advice on where they might sit in >> the file system. What makes this one different? This one. >> >> What happens when you use the wrong helper? >> >> >> > UB - in most cases, eBPF program will work with wrong configurations. >> > That's why the stamp was added. >> > >> > query-helper-paths checks the stamp only for RSS helper. >> >> I have no idea what you're talking about :) >> >> My best guess is that you're trying to tell me that attempting to work >> with the wrong helper will fail cleanly due to some stamp check. That >> would be nice. >> >>
