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 #include <asm/spectre.h> 12 13 #include <nvhe/early_alloc.h> 14 #include <nvhe/gfp.h> 15 #include <nvhe/memory.h> 16 #include <nvhe/mm.h> 17 #include <nvhe/spinlock.h> 18 19 struct kvm_pgtable pkvm_pgtable; 20 hyp_spinlock_t pkvm_pgd_lock; 21 u64 __io_map_base; 22 23 struct memblock_region hyp_memory[HYP_MEMBLOCK_REGIONS]; 24 unsigned int hyp_memblock_nr; 25 26 int __pkvm_create_mappings(unsigned long start, unsigned long size, 27 unsigned long phys, enum kvm_pgtable_prot prot) 28 { 29 int err; 30 31 hyp_spin_lock(&pkvm_pgd_lock); 32 err = kvm_pgtable_hyp_map(&pkvm_pgtable, start, size, phys, prot); 33 hyp_spin_unlock(&pkvm_pgd_lock); 34 35 return err; 36 } 37 38 unsigned long __pkvm_create_private_mapping(phys_addr_t phys, size_t size, 39 enum kvm_pgtable_prot prot) 40 { 41 unsigned long addr; 42 int err; 43 44 hyp_spin_lock(&pkvm_pgd_lock); 45 46 size = PAGE_ALIGN(size + offset_in_page(phys)); 47 addr = __io_map_base; 48 __io_map_base += size; 49 50 /* Are we overflowing on the vmemmap ? */ 51 if (__io_map_base > __hyp_vmemmap) { 52 __io_map_base -= size; 53 addr = (unsigned long)ERR_PTR(-ENOMEM); 54 goto out; 55 } 56 57 err = kvm_pgtable_hyp_map(&pkvm_pgtable, addr, size, phys, prot); 58 if (err) { 59 addr = (unsigned long)ERR_PTR(err); 60 goto out; 61 } 62 63 addr = addr + offset_in_page(phys); 64 out: 65 hyp_spin_unlock(&pkvm_pgd_lock); 66 67 return addr; 68 } 69 70 int pkvm_create_mappings(void *from, void *to, enum kvm_pgtable_prot prot) 71 { 72 unsigned long start = (unsigned long)from; 73 unsigned long end = (unsigned long)to; 74 unsigned long virt_addr; 75 phys_addr_t phys; 76 77 start = start & PAGE_MASK; 78 end = PAGE_ALIGN(end); 79 80 for (virt_addr = start; virt_addr < end; virt_addr += PAGE_SIZE) { 81 int err; 82 83 phys = hyp_virt_to_phys((void *)virt_addr); 84 err = __pkvm_create_mappings(virt_addr, PAGE_SIZE, phys, prot); 85 if (err) 86 return err; 87 } 88 89 return 0; 90 } 91 92 int hyp_back_vmemmap(phys_addr_t phys, unsigned long size, phys_addr_t back) 93 { 94 unsigned long start, end; 95 96 hyp_vmemmap_range(phys, size, &start, &end); 97 98 return __pkvm_create_mappings(start, end - start, back, PAGE_HYP); 99 } 100 101 static void *__hyp_bp_vect_base; 102 int pkvm_cpu_set_vector(enum arm64_hyp_spectre_vector slot) 103 { 104 void *vector; 105 106 switch (slot) { 107 case HYP_VECTOR_DIRECT: { 108 vector = __kvm_hyp_vector; 109 break; 110 } 111 case HYP_VECTOR_SPECTRE_DIRECT: { 112 vector = __bp_harden_hyp_vecs; 113 break; 114 } 115 case HYP_VECTOR_INDIRECT: 116 case HYP_VECTOR_SPECTRE_INDIRECT: { 117 vector = (void *)__hyp_bp_vect_base; 118 break; 119 } 120 default: 121 return -EINVAL; 122 } 123 124 vector = __kvm_vector_slot2addr(vector, slot); 125 *this_cpu_ptr(&kvm_hyp_vector) = (unsigned long)vector; 126 127 return 0; 128 } 129 130 int hyp_map_vectors(void) 131 { 132 phys_addr_t phys; 133 void *bp_base; 134 135 if (!cpus_have_const_cap(ARM64_SPECTRE_V3A)) 136 return 0; 137 138 phys = __hyp_pa(__bp_harden_hyp_vecs); 139 bp_base = (void *)__pkvm_create_private_mapping(phys, 140 __BP_HARDEN_HYP_VECS_SZ, 141 PAGE_HYP_EXEC); 142 if (IS_ERR_OR_NULL(bp_base)) 143 return PTR_ERR(bp_base); 144 145 __hyp_bp_vect_base = bp_base; 146 147 return 0; 148 } 149 150 int hyp_create_idmap(u32 hyp_va_bits) 151 { 152 unsigned long start, end; 153 154 start = hyp_virt_to_phys((void *)__hyp_idmap_text_start); 155 start = ALIGN_DOWN(start, PAGE_SIZE); 156 157 end = hyp_virt_to_phys((void *)__hyp_idmap_text_end); 158 end = ALIGN(end, PAGE_SIZE); 159 160 /* 161 * One half of the VA space is reserved to linearly map portions of 162 * memory -- see va_layout.c for more details. The other half of the VA 163 * space contains the trampoline page, and needs some care. Split that 164 * second half in two and find the quarter of VA space not conflicting 165 * with the idmap to place the IOs and the vmemmap. IOs use the lower 166 * half of the quarter and the vmemmap the upper half. 167 */ 168 __io_map_base = start & BIT(hyp_va_bits - 2); 169 __io_map_base ^= BIT(hyp_va_bits - 2); 170 __hyp_vmemmap = __io_map_base | BIT(hyp_va_bits - 3); 171 172 return __pkvm_create_mappings(start, end - start, start, PAGE_HYP_EXEC); 173 } 174