On Thu, Sep 08, 2022, Sean Christopherson wrote: > On Mon, Aug 22, 2022, Paolo Bonzini wrote: > > The following backtrace: > > Paolo Bonzini (6): > > KVM: x86: check validity of argument to KVM_SET_MP_STATE > > Skipping this one since it's already in 6.0 and AFAICT isn't strictly necessary > for the rest of the series (shouldn't matter anyways?). > > > KVM: x86: make vendor code check for all nested events > > KVM: x86: lapic does not have to process INIT if it is blocked > > KVM: x86: never write to memory from kvm_vcpu_check_block > > KVM: mips, x86: do not rely on KVM_REQ_UNHALT > > KVM: remove KVM_REQ_UNHALT > > > > Sean Christopherson (1): > > KVM: nVMX: Make an event request when pending an MTF nested VM-Exit > > Pushed to branch `for_paolo/6.1` at: > > https://github.com/sean-jc/linux.git > > with a cosmetic cleanup to kvm_apic_has_events() and the MTF migration fix squashed > in. Oh the irony about complaining that people waste maintainers' time by not running existing tests :-) I suppose it's not technically ironic since I was the one doing the actual complaining, but it's still hilarious. The eponymous patch breaks handling of INITs (and SIPIs) that are "latched"[1] and later become unblocked, e.g. due to entering VMX non-root mode or because SVM's GIF is set. vmx_init_signal_test fails because KVM fails to re-evaluate pending events after entering guest/non-root. It passes now because KVM always checks nested events in the outer run loop. I have fixes, I'll (temporarily) drop this from the queue and post a new version of this series on Monday. As a reward to myself for bisecting and debugging, I'm going to tweak "KVM: x86: lapic does not have to process INIT if it is blocked" to incorporate my suggestions[2] from v2 so that the VMX and SVM code can check only for pending INIT/SIPI and not include the blocking check to align with related checks that also trigger KVM_REQ_EVENT (and because the resulting SVM GIF code would be quite fragile if the blocking were incorporated). [1] It annoys me to no end that KVM uses different terminology for INIT/SIPI versus everything else. [2] https://lore.kernel.org/all/YvwxJzHC5xYnc7CJ@xxxxxxxxxx
