1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) 2020 Google LLC 4 * Author: Quentin Perret <qperret@google.com> 5 */ 6 7 #include <linux/kvm_host.h> 8 #include <asm/kvm_hyp.h> 9 #include <asm/kvm_mmu.h> 10 #include <asm/kvm_pgtable.h> 11 12 #include <nvhe/early_alloc.h> 13 #include <nvhe/gfp.h> 14 #include <nvhe/memory.h> 15 #include <nvhe/mem_protect.h> 16 #include <nvhe/mm.h> 17 #include <nvhe/trap_handler.h> 18 19 struct hyp_pool hpool; 20 struct kvm_pgtable_mm_ops pkvm_pgtable_mm_ops; 21 unsigned long hyp_nr_cpus; 22 23 #define hyp_percpu_size ((unsigned long)__per_cpu_end - \ 24 (unsigned long)__per_cpu_start) 25 26 static void *vmemmap_base; 27 static void *hyp_pgt_base; 28 static void *host_s2_mem_pgt_base; 29 static void *host_s2_dev_pgt_base; 30 31 static int divide_memory_pool(void *virt, unsigned long size) 32 { 33 unsigned long vstart, vend, nr_pages; 34 35 hyp_early_alloc_init(virt, size); 36 37 hyp_vmemmap_range(__hyp_pa(virt), size, &vstart, &vend); 38 nr_pages = (vend - vstart) >> PAGE_SHIFT; 39 vmemmap_base = hyp_early_alloc_contig(nr_pages); 40 if (!vmemmap_base) 41 return -ENOMEM; 42 43 nr_pages = hyp_s1_pgtable_pages(); 44 hyp_pgt_base = hyp_early_alloc_contig(nr_pages); 45 if (!hyp_pgt_base) 46 return -ENOMEM; 47 48 nr_pages = host_s2_mem_pgtable_pages(); 49 host_s2_mem_pgt_base = hyp_early_alloc_contig(nr_pages); 50 if (!host_s2_mem_pgt_base) 51 return -ENOMEM; 52 53 nr_pages = host_s2_dev_pgtable_pages(); 54 host_s2_dev_pgt_base = hyp_early_alloc_contig(nr_pages); 55 if (!host_s2_dev_pgt_base) 56 return -ENOMEM; 57 58 return 0; 59 } 60 61 static int recreate_hyp_mappings(phys_addr_t phys, unsigned long size, 62 unsigned long *per_cpu_base, 63 u32 hyp_va_bits) 64 { 65 void *start, *end, *virt = hyp_phys_to_virt(phys); 66 unsigned long pgt_size = hyp_s1_pgtable_pages() << PAGE_SHIFT; 67 int ret, i; 68 69 /* Recreate the hyp page-table using the early page allocator */ 70 hyp_early_alloc_init(hyp_pgt_base, pgt_size); 71 ret = kvm_pgtable_hyp_init(&pkvm_pgtable, hyp_va_bits, 72 &hyp_early_alloc_mm_ops); 73 if (ret) 74 return ret; 75 76 ret = hyp_create_idmap(hyp_va_bits); 77 if (ret) 78 return ret; 79 80 ret = hyp_map_vectors(); 81 if (ret) 82 return ret; 83 84 ret = hyp_back_vmemmap(phys, size, hyp_virt_to_phys(vmemmap_base)); 85 if (ret) 86 return ret; 87 88 ret = pkvm_create_mappings(__hyp_text_start, __hyp_text_end, PAGE_HYP_EXEC); 89 if (ret) 90 return ret; 91 92 ret = pkvm_create_mappings(__start_rodata, __end_rodata, PAGE_HYP_RO); 93 if (ret) 94 return ret; 95 96 ret = pkvm_create_mappings(__hyp_rodata_start, __hyp_rodata_end, PAGE_HYP_RO); 97 if (ret) 98 return ret; 99 100 ret = pkvm_create_mappings(__hyp_bss_start, __hyp_bss_end, PAGE_HYP); 101 if (ret) 102 return ret; 103 104 ret = pkvm_create_mappings(__hyp_bss_end, __bss_stop, PAGE_HYP_RO); 105 if (ret) 106 return ret; 107 108 ret = pkvm_create_mappings(virt, virt + size, PAGE_HYP); 109 if (ret) 110 return ret; 111 112 for (i = 0; i < hyp_nr_cpus; i++) { 113 start = (void *)kern_hyp_va(per_cpu_base[i]); 114 end = start + PAGE_ALIGN(hyp_percpu_size); 115 ret = pkvm_create_mappings(start, end, PAGE_HYP); 116 if (ret) 117 return ret; 118 119 end = (void *)per_cpu_ptr(&kvm_init_params, i)->stack_hyp_va; 120 start = end - PAGE_SIZE; 121 ret = pkvm_create_mappings(start, end, PAGE_HYP); 122 if (ret) 123 return ret; 124 } 125 126 return 0; 127 } 128 129 static void update_nvhe_init_params(void) 130 { 131 struct kvm_nvhe_init_params *params; 132 unsigned long i; 133 134 for (i = 0; i < hyp_nr_cpus; i++) { 135 params = per_cpu_ptr(&kvm_init_params, i); 136 params->pgd_pa = __hyp_pa(pkvm_pgtable.pgd); 137 __flush_dcache_area(params, sizeof(*params)); 138 } 139 } 140 141 static void *hyp_zalloc_hyp_page(void *arg) 142 { 143 return hyp_alloc_pages(&hpool, 0); 144 } 145 146 void __noreturn __pkvm_init_finalise(void) 147 { 148 struct kvm_host_data *host_data = this_cpu_ptr(&kvm_host_data); 149 struct kvm_cpu_context *host_ctxt = &host_data->host_ctxt; 150 unsigned long nr_pages, reserved_pages, pfn; 151 int ret; 152 153 /* Now that the vmemmap is backed, install the full-fledged allocator */ 154 pfn = hyp_virt_to_pfn(hyp_pgt_base); 155 nr_pages = hyp_s1_pgtable_pages(); 156 reserved_pages = hyp_early_alloc_nr_used_pages(); 157 ret = hyp_pool_init(&hpool, pfn, nr_pages, reserved_pages); 158 if (ret) 159 goto out; 160 161 ret = kvm_host_prepare_stage2(host_s2_mem_pgt_base, host_s2_dev_pgt_base); 162 if (ret) 163 goto out; 164 165 pkvm_pgtable_mm_ops = (struct kvm_pgtable_mm_ops) { 166 .zalloc_page = hyp_zalloc_hyp_page, 167 .phys_to_virt = hyp_phys_to_virt, 168 .virt_to_phys = hyp_virt_to_phys, 169 .get_page = hyp_get_page, 170 .put_page = hyp_put_page, 171 }; 172 pkvm_pgtable.mm_ops = &pkvm_pgtable_mm_ops; 173 174 out: 175 /* 176 * We tail-called to here from handle___pkvm_init() and will not return, 177 * so make sure to propagate the return value to the host. 178 */ 179 cpu_reg(host_ctxt, 1) = ret; 180 181 __host_enter(host_ctxt); 182 } 183 184 int __pkvm_init(phys_addr_t phys, unsigned long size, unsigned long nr_cpus, 185 unsigned long *per_cpu_base, u32 hyp_va_bits) 186 { 187 struct kvm_nvhe_init_params *params; 188 void *virt = hyp_phys_to_virt(phys); 189 void (*fn)(phys_addr_t params_pa, void *finalize_fn_va); 190 int ret; 191 192 if (!PAGE_ALIGNED(phys) || !PAGE_ALIGNED(size)) 193 return -EINVAL; 194 195 hyp_spin_lock_init(&pkvm_pgd_lock); 196 hyp_nr_cpus = nr_cpus; 197 198 ret = divide_memory_pool(virt, size); 199 if (ret) 200 return ret; 201 202 ret = recreate_hyp_mappings(phys, size, per_cpu_base, hyp_va_bits); 203 if (ret) 204 return ret; 205 206 update_nvhe_init_params(); 207 208 /* Jump in the idmap page to switch to the new page-tables */ 209 params = this_cpu_ptr(&kvm_init_params); 210 fn = (typeof(fn))__hyp_pa(__pkvm_init_switch_pgd); 211 fn(__hyp_pa(params), __pkvm_init_finalise); 212 213 unreachable(); 214 } 215