vmcs_setreg
ret = vmcs_setreg(vmcs, running, ident, val);
int vmcs_setreg(struct vmcs *vmcs, int running, int ident, uint64_t val);
error = vmcs_setreg(vmcs, 0, VMCS_IDENT(mask_ident), mask_value);
error = vmcs_setreg(vmcs, 0, VMCS_IDENT(shadow_ident), initial);
error = vmcs_setreg(vmcs, running, ident, gi);
error = vmcs_setreg(vcpu->vmcs, running, reg, val);
vmcs_setreg(vcpu->vmcs, running,
error = vmcs_setreg(vcpu->vmcs, running,