kvm_mmu_get_guest_pgd
root_pgd = kvm_mmu_get_guest_pgd(vcpu, mmu);
arch.cr3 = kvm_mmu_get_guest_pgd(vcpu, vcpu->arch.mmu);
work->arch.cr3 != kvm_mmu_get_guest_pgd(vcpu, vcpu->arch.mmu))
pte = kvm_mmu_get_guest_pgd(vcpu, mmu);