Concerns were expressed around (ab)using #PF for KVM's async_pf mechanism, it seems that re-using #PF exception for a PV mechanism wasn't a great idea after all. The Grand Plan is to switch to using e.g. #VE for 'page not present' events and normal APIC interrupts for 'page present' events. This RFC does the later. Please let me know what you think about the idea in general and the selected approach in particular. Vitaly Kuznetsov (6): Revert "KVM: async_pf: Fix #DF due to inject "Page not Present" and "Page Ready" exceptions simultaneously" KVM: x86: extend struct kvm_vcpu_pv_apf_data with token info KVM: x86: interrupt based APF page-ready event delivery KVM: x86: acknowledgment mechanism for async pf page ready notifications KVM: x86: announce KVM_FEATURE_ASYNC_PF_INT KVM: x86: Switch KVM guest to using interrupts for page ready APF delivery Documentation/virt/kvm/cpuid.rst | 6 ++ Documentation/virt/kvm/msr.rst | 52 +++++++++++-- arch/x86/entry/entry_32.S | 5 ++ arch/x86/entry/entry_64.S | 5 ++ arch/x86/include/asm/hardirq.h | 3 + arch/x86/include/asm/irq_vectors.h | 6 +- arch/x86/include/asm/kvm_host.h | 5 +- arch/x86/include/asm/kvm_para.h | 6 ++ arch/x86/include/uapi/asm/kvm_para.h | 11 ++- arch/x86/kernel/irq.c | 9 +++ arch/x86/kernel/kvm.c | 42 +++++++++++ arch/x86/kvm/cpuid.c | 3 +- arch/x86/kvm/x86.c | 107 +++++++++++++++++++++------ include/uapi/linux/kvm.h | 1 + 14 files changed, 228 insertions(+), 33 deletions(-) -- 2.25.3