>>> As for nesting, I suggest for the foreseeable future we stick to XICS >>> emulation in nested guests. >> >> ok. so no kernel_irqchip at all. hmm. I was confused with what Paul calls 'XICS emulation'. It's not the QEMU XICS emulated device but the XICS-over-XIVE KVM device, the KVM XICS device KVM uses when under a P9 processor. > That would certainly be step 0, making sure the capability advertises > this correctly. I think we do want to make XICs-on-XIVE emulation > work in a KVM L1 (so we'd need to have it make XIVE hcalls to the L0 > instead of OPAL calls). With the latest patch of Paul, the KVM XICS device is available for L2 and it works quite well. I also want to test it when L1 runs in KVM XIVE native mode, with the current patchset, to see how it behaves. > XIVE-on-XIVE for L1 would be nice too, which would mean implementing > the XIVE hcalls from the L2 in terms of XIVE hcalls to the L0. I > think it's ok to delay this indefinitely as long as the caps advertise > correctly so that qemu will use userspace emulation until its ready. ok. I need to fix this in the current patchset. Thanks, C.
