void __init kvm_cma_reserve(void)
 {
        unsigned long align_size;
-       struct memblock_region *reg;
-       phys_addr_t selected_size = 0;
+       phys_addr_t selected_size;
 
        /*
         * We need CMA reservation only when we are in HV mode
         */
        if (!cpu_has_feature(CPU_FTR_HVMODE))
                return;
-       /*
-        * We cannot use memblock_phys_mem_size() here, because
-        * memblock_analyze() has not been called yet.
-        */
-       for_each_memblock(memory, reg)
-               selected_size += memblock_region_memory_end_pfn(reg) -
-                                memblock_region_memory_base_pfn(reg);
 
-       selected_size = (selected_size * kvm_cma_resv_ratio / 100) << PAGE_SHIFT;
+       selected_size = PAGE_ALIGN(memblock_phys_mem_size() * kvm_cma_resv_ratio / 100);
        if (selected_size) {
                pr_info("%s: reserving %ld MiB for global area\n", __func__,
                         (unsigned long)selected_size / SZ_1M);