1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (C) 2020 - Google LLC 4 * Author: Quentin Perret <qperret@google.com> 5 */ 6 7 #include <linux/kvm_host.h> 8 #include <linux/memblock.h> 9 #include <linux/sort.h> 10 11 #include <asm/kvm_pkvm.h> 12 13 #include "hyp_constants.h" 14 15 static struct memblock_region *hyp_memory = kvm_nvhe_sym(hyp_memory); 16 static unsigned int *hyp_memblock_nr_ptr = &kvm_nvhe_sym(hyp_memblock_nr); 17 18 phys_addr_t hyp_mem_base; 19 phys_addr_t hyp_mem_size; 20 21 static int cmp_hyp_memblock(const void *p1, const void *p2) 22 { 23 const struct memblock_region *r1 = p1; 24 const struct memblock_region *r2 = p2; 25 26 return r1->base < r2->base ? -1 : (r1->base > r2->base); 27 } 28 29 static void __init sort_memblock_regions(void) 30 { 31 sort(hyp_memory, 32 *hyp_memblock_nr_ptr, 33 sizeof(struct memblock_region), 34 cmp_hyp_memblock, 35 NULL); 36 } 37 38 static int __init register_memblock_regions(void) 39 { 40 struct memblock_region *reg; 41 42 for_each_mem_region(reg) { 43 if (*hyp_memblock_nr_ptr >= HYP_MEMBLOCK_REGIONS) 44 return -ENOMEM; 45 46 hyp_memory[*hyp_memblock_nr_ptr] = *reg; 47 (*hyp_memblock_nr_ptr)++; 48 } 49 sort_memblock_regions(); 50 51 return 0; 52 } 53 54 void __init kvm_hyp_reserve(void) 55 { 56 u64 nr_pages, prev, hyp_mem_pages = 0; 57 int ret; 58 59 if (!is_hyp_mode_available() || is_kernel_in_hyp_mode()) 60 return; 61 62 if (kvm_get_mode() != KVM_MODE_PROTECTED) 63 return; 64 65 ret = register_memblock_regions(); 66 if (ret) { 67 *hyp_memblock_nr_ptr = 0; 68 kvm_err("Failed to register hyp memblocks: %d\n", ret); 69 return; 70 } 71 72 hyp_mem_pages += hyp_s1_pgtable_pages(); 73 hyp_mem_pages += host_s2_pgtable_pages(); 74 75 /* 76 * The hyp_vmemmap needs to be backed by pages, but these pages 77 * themselves need to be present in the vmemmap, so compute the number 78 * of pages needed by looking for a fixed point. 79 */ 80 nr_pages = 0; 81 do { 82 prev = nr_pages; 83 nr_pages = hyp_mem_pages + prev; 84 nr_pages = DIV_ROUND_UP(nr_pages * STRUCT_HYP_PAGE_SIZE, 85 PAGE_SIZE); 86 nr_pages += __hyp_pgtable_max_pages(nr_pages); 87 } while (nr_pages != prev); 88 hyp_mem_pages += nr_pages; 89 90 /* 91 * Try to allocate a PMD-aligned region to reduce TLB pressure once 92 * this is unmapped from the host stage-2, and fallback to PAGE_SIZE. 93 */ 94 hyp_mem_size = hyp_mem_pages << PAGE_SHIFT; 95 hyp_mem_base = memblock_phys_alloc(ALIGN(hyp_mem_size, PMD_SIZE), 96 PMD_SIZE); 97 if (!hyp_mem_base) 98 hyp_mem_base = memblock_phys_alloc(hyp_mem_size, PAGE_SIZE); 99 else 100 hyp_mem_size = ALIGN(hyp_mem_size, PMD_SIZE); 101 102 if (!hyp_mem_base) { 103 kvm_err("Failed to reserve hyp memory\n"); 104 return; 105 } 106 107 kvm_info("Reserved %lld MiB at 0x%llx\n", hyp_mem_size >> 20, 108 hyp_mem_base); 109 } 110