On 08/02/2018 09:57, Xiao Guangrong wrote: >> Maybe it should return RET_PF_EMULATE, which would cause an emulation >> failure and then an exit with KVM_EXIT_INTERNAL_ERROR. > > So the root cause is that a running vCPU accessing the memory whose memslot > is being updated (met the condition KVM_MEMSLOT_INVALID is set on the its > memslot). > > The normal #PF handler breaks KVM_RUN and returns -EFAULT to userspace, > we'd better to make ept-misconfig's handler follow this style as well. Why return -EFAULT and not attempt emulation (which will fail)? Paolo