Receiving an unexpected exit reason from hardware should be considered as a severe bug in KVM. Therefore, instead of just injecting #UD to guest and ignore it, exit to userspace on internal error so that it could handle it properly (probably by terminating guest). In addition, prefer to use vcpu_unimpl() instead of WARN_ONCE() as handling unexpected exit reason should be a rare unexpected event (that was expected to never happen) and we prefer to print a message on it every time it occurs to guest. Furthermore, dump VMCS/VMCB to dmesg to assist diagnosing such cases.
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| @@ -243,6 +243,8 @@ struct kvm_hyperv_exit { · 242 unmodified lines | |||
| 243 | #define KVM_INTERNAL_ERROR_SIMUL_EX 2 | 243 | #define KVM_INTERNAL_ERROR_SIMUL_EX 2 |
| 244 | /* Encounter unexpected vm-exit due to delivery event. */ | 244 | /* Encounter unexpected vm-exit due to delivery event. */ |
| 245 | #define KVM_INTERNAL_ERROR_DELIVERY_EV 3 | 245 | #define KVM_INTERNAL_ERROR_DELIVERY_EV 3 |
| 246 | /* Encounter unexpected vm-exit reason */ | ||
| 247 | #define KVM_INTERNAL_ERROR_UNEXPECTED_EXIT_REASON 4 | ||
| 246 | 248 | ||
| 247 | /* for KVM_RUN, returned by mmap(vcpu_fd, offset=0) */ | 249 | /* for KVM_RUN, returned by mmap(vcpu_fd, offset=0) */ |
| 248 | struct kvm_run { | 250 | struct kvm_run { |