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 unsigned long hyp_nr_cpus; 21 22 #define hyp_percpu_size ((unsigned long)__per_cpu_end - \ 23 (unsigned long)__per_cpu_start) 24 25 static void *vmemmap_base; 26 static void *hyp_pgt_base; 27 static void *host_s2_pgt_base; 28 static struct kvm_pgtable_mm_ops pkvm_pgtable_mm_ops; 29 30 static int divide_memory_pool(void *virt, unsigned long size) 31 { 32 unsigned long vstart, vend, nr_pages; 33 34 hyp_early_alloc_init(virt, size); 35 36 hyp_vmemmap_range(__hyp_pa(virt), size, &vstart, &vend); 37 nr_pages = (vend - vstart) >> PAGE_SHIFT; 38 vmemmap_base = hyp_early_alloc_contig(nr_pages); 39 if (!vmemmap_base) 40 return -ENOMEM; 41 42 nr_pages = hyp_s1_pgtable_pages(); 43 hyp_pgt_base = hyp_early_alloc_contig(nr_pages); 44 if (!hyp_pgt_base) 45 return -ENOMEM; 46 47 nr_pages = host_s2_pgtable_pages(); 48 host_s2_pgt_base = hyp_early_alloc_contig(nr_pages); 49 if (!host_s2_pgt_base) 50 return -ENOMEM; 51 52 return 0; 53 } 54 55 static int recreate_hyp_mappings(phys_addr_t phys, unsigned long size, 56 unsigned long *per_cpu_base, 57 u32 hyp_va_bits) 58 { 59 void *start, *end, *virt = hyp_phys_to_virt(phys); 60 unsigned long pgt_size = hyp_s1_pgtable_pages() << PAGE_SHIFT; 61 int ret, i; 62 63 /* Recreate the hyp page-table using the early page allocator */ 64 hyp_early_alloc_init(hyp_pgt_base, pgt_size); 65 ret = kvm_pgtable_hyp_init(&pkvm_pgtable, hyp_va_bits, 66 &hyp_early_alloc_mm_ops); 67 if (ret) 68 return ret; 69 70 ret = hyp_create_idmap(hyp_va_bits); 71 if (ret) 72 return ret; 73 74 ret = hyp_map_vectors(); 75 if (ret) 76 return ret; 77 78 ret = hyp_back_vmemmap(phys, size, hyp_virt_to_phys(vmemmap_base)); 79 if (ret) 80 return ret; 81 82 ret = pkvm_create_mappings(__hyp_text_start, __hyp_text_end, PAGE_HYP_EXEC); 83 if (ret) 84 return ret; 85 86 ret = pkvm_create_mappings(__start_rodata, __end_rodata, PAGE_HYP_RO); 87 if (ret) 88 return ret; 89 90 ret = pkvm_create_mappings(__hyp_rodata_start, __hyp_rodata_end, PAGE_HYP_RO); 91 if (ret) 92 return ret; 93 94 ret = pkvm_create_mappings(__hyp_bss_start, __hyp_bss_end, PAGE_HYP); 95 if (ret) 96 return ret; 97 98 ret = pkvm_create_mappings(__hyp_bss_end, __bss_stop, PAGE_HYP_RO); 99 if (ret) 100 return ret; 101 102 ret = pkvm_create_mappings(virt, virt + size, PAGE_HYP); 103 if (ret) 104 return ret; 105 106 for (i = 0; i < hyp_nr_cpus; i++) { 107 start = (void *)kern_hyp_va(per_cpu_base[i]); 108 end = start + PAGE_ALIGN(hyp_percpu_size); 109 ret = pkvm_create_mappings(start, end, PAGE_HYP); 110 if (ret) 111 return ret; 112 113 end = (void *)per_cpu_ptr(&kvm_init_params, i)->stack_hyp_va; 114 start = end - PAGE_SIZE; 115 ret = pkvm_create_mappings(start, end, PAGE_HYP); 116 if (ret) 117 return ret; 118 } 119 120 return 0; 121 } 122 123 static void update_nvhe_init_params(void) 124 { 125 struct kvm_nvhe_init_params *params; 126 unsigned long i; 127 128 for (i = 0; i < hyp_nr_cpus; i++) { 129 params = per_cpu_ptr(&kvm_init_params, i); 130 params->pgd_pa = __hyp_pa(pkvm_pgtable.pgd); 131 dcache_clean_inval_poc((unsigned long)params, 132 (unsigned long)params + sizeof(*params)); 133 } 134 } 135 136 static void *hyp_zalloc_hyp_page(void *arg) 137 { 138 return hyp_alloc_pages(&hpool, 0); 139 } 140 141 static void hpool_get_page(void *addr) 142 { 143 hyp_get_page(&hpool, addr); 144 } 145 146 static void hpool_put_page(void *addr) 147 { 148 hyp_put_page(&hpool, addr); 149 } 150 151 void __noreturn __pkvm_init_finalise(void) 152 { 153 struct kvm_host_data *host_data = this_cpu_ptr(&kvm_host_data); 154 struct kvm_cpu_context *host_ctxt = &host_data->host_ctxt; 155 unsigned long nr_pages, reserved_pages, pfn; 156 int ret; 157 158 /* Now that the vmemmap is backed, install the full-fledged allocator */ 159 pfn = hyp_virt_to_pfn(hyp_pgt_base); 160 nr_pages = hyp_s1_pgtable_pages(); 161 reserved_pages = hyp_early_alloc_nr_used_pages(); 162 ret = hyp_pool_init(&hpool, pfn, nr_pages, reserved_pages); 163 if (ret) 164 goto out; 165 166 ret = kvm_host_prepare_stage2(host_s2_pgt_base); 167 if (ret) 168 goto out; 169 170 pkvm_pgtable_mm_ops = (struct kvm_pgtable_mm_ops) { 171 .zalloc_page = hyp_zalloc_hyp_page, 172 .phys_to_virt = hyp_phys_to_virt, 173 .virt_to_phys = hyp_virt_to_phys, 174 .get_page = hpool_get_page, 175 .put_page = hpool_put_page, 176 }; 177 pkvm_pgtable.mm_ops = &pkvm_pgtable_mm_ops; 178 179 out: 180 /* 181 * We tail-called to here from handle___pkvm_init() and will not return, 182 * so make sure to propagate the return value to the host. 183 */ 184 cpu_reg(host_ctxt, 1) = ret; 185 186 __host_enter(host_ctxt); 187 } 188 189 int __pkvm_init(phys_addr_t phys, unsigned long size, unsigned long nr_cpus, 190 unsigned long *per_cpu_base, u32 hyp_va_bits) 191 { 192 struct kvm_nvhe_init_params *params; 193 void *virt = hyp_phys_to_virt(phys); 194 void (*fn)(phys_addr_t params_pa, void *finalize_fn_va); 195 int ret; 196 197 if (!PAGE_ALIGNED(phys) || !PAGE_ALIGNED(size)) 198 return -EINVAL; 199 200 hyp_spin_lock_init(&pkvm_pgd_lock); 201 hyp_nr_cpus = nr_cpus; 202 203 ret = divide_memory_pool(virt, size); 204 if (ret) 205 return ret; 206 207 ret = recreate_hyp_mappings(phys, size, per_cpu_base, hyp_va_bits); 208 if (ret) 209 return ret; 210 211 update_nvhe_init_params(); 212 213 /* Jump in the idmap page to switch to the new page-tables */ 214 params = this_cpu_ptr(&kvm_init_params); 215 fn = (typeof(fn))__hyp_pa(__pkvm_init_switch_pgd); 216 fn(__hyp_pa(params), __pkvm_init_finalise); 217 218 unreachable(); 219 } 220