Can guest vm memory be accessed by host kernel ?

when we start a guest vm with KVM, guest vm memory is allocated through KVM ioctl.
Does the guest memory(allocated by KVM) can be accessed by host kernel?
after KVM allocate memory to guest, Will KVM remove the allocated memory from host kernel address space( Remove these corresponding page table entry )?
Or guest vm just is a userspace process of host kernel, host kernel can access whole guest memory?