vmcb_msr_ptr
const uint64_t *msrp = vmcb_msr_ptr(vmcb, msr, NULL);
uint64_t *msrp = vmcb_msr_ptr(vmcb, msr, &dirty);
uint64_t *vmcb_msr_ptr(struct vmcb *vmcb, uint32_t ident, uint32_t *dirtyp);