1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (C) 2020 - Google LLC
4 * Author: Quentin Perret <qperret@google.com>
7 #include <linux/init.h>
8 #include <linux/kmemleak.h>
9 #include <linux/kvm_host.h>
10 #include <linux/memblock.h>
11 #include <linux/mutex.h>
12 #include <linux/sort.h>
14 #include <asm/kvm_pkvm.h>
16 #include "hyp_constants.h"
18 DEFINE_STATIC_KEY_FALSE(kvm_protected_mode_initialized);
20 static struct memblock_region *hyp_memory = kvm_nvhe_sym(hyp_memory);
21 static unsigned int *hyp_memblock_nr_ptr = &kvm_nvhe_sym(hyp_memblock_nr);
23 phys_addr_t hyp_mem_base;
24 phys_addr_t hyp_mem_size;
26 static int cmp_hyp_memblock(const void *p1, const void *p2)
28 const struct memblock_region *r1 = p1;
29 const struct memblock_region *r2 = p2;
31 return r1->base < r2->base ? -1 : (r1->base > r2->base);
34 static void __init sort_memblock_regions(void)
38 sizeof(struct memblock_region),
43 static int __init register_memblock_regions(void)
45 struct memblock_region *reg;
47 for_each_mem_region(reg) {
48 if (*hyp_memblock_nr_ptr >= HYP_MEMBLOCK_REGIONS)
51 hyp_memory[*hyp_memblock_nr_ptr] = *reg;
52 (*hyp_memblock_nr_ptr)++;
54 sort_memblock_regions();
59 void __init kvm_hyp_reserve(void)
61 u64 hyp_mem_pages = 0;
64 if (!is_hyp_mode_available() || is_kernel_in_hyp_mode())
67 if (kvm_get_mode() != KVM_MODE_PROTECTED)
70 ret = register_memblock_regions();
72 *hyp_memblock_nr_ptr = 0;
73 kvm_err("Failed to register hyp memblocks: %d\n", ret);
77 hyp_mem_pages += hyp_s1_pgtable_pages();
78 hyp_mem_pages += host_s2_pgtable_pages();
79 hyp_mem_pages += hyp_vm_table_pages();
80 hyp_mem_pages += hyp_vmemmap_pages(STRUCT_HYP_PAGE_SIZE);
81 hyp_mem_pages += hyp_ffa_proxy_pages();
84 * Try to allocate a PMD-aligned region to reduce TLB pressure once
85 * this is unmapped from the host stage-2, and fallback to PAGE_SIZE.
87 hyp_mem_size = hyp_mem_pages << PAGE_SHIFT;
88 hyp_mem_base = memblock_phys_alloc(ALIGN(hyp_mem_size, PMD_SIZE),
91 hyp_mem_base = memblock_phys_alloc(hyp_mem_size, PAGE_SIZE);
93 hyp_mem_size = ALIGN(hyp_mem_size, PMD_SIZE);
96 kvm_err("Failed to reserve hyp memory\n");
100 kvm_info("Reserved %lld MiB at 0x%llx\n", hyp_mem_size >> 20,
105 * Allocates and donates memory for hypervisor VM structs at EL2.
107 * Allocates space for the VM state, which includes the hyp vm as well as
110 * Stores an opaque handler in the kvm struct for future reference.
112 * Return 0 on success, negative error code on failure.
114 static int __pkvm_create_hyp_vm(struct kvm *host_kvm)
116 size_t pgd_sz, hyp_vm_sz, hyp_vcpu_sz;
117 struct kvm_vcpu *host_vcpu;
118 pkvm_handle_t handle;
123 if (host_kvm->created_vcpus < 1)
126 pgd_sz = kvm_pgtable_stage2_pgd_size(host_kvm->arch.mmu.vtcr);
129 * The PGD pages will be reclaimed using a hyp_memcache which implies
130 * page granularity. So, use alloc_pages_exact() to get individual
133 pgd = alloc_pages_exact(pgd_sz, GFP_KERNEL_ACCOUNT);
137 /* Allocate memory to donate to hyp for vm and vcpu pointers. */
138 hyp_vm_sz = PAGE_ALIGN(size_add(PKVM_HYP_VM_SIZE,
139 size_mul(sizeof(void *),
140 host_kvm->created_vcpus)));
141 hyp_vm = alloc_pages_exact(hyp_vm_sz, GFP_KERNEL_ACCOUNT);
147 /* Donate the VM memory to hyp and let hyp initialize it. */
148 ret = kvm_call_hyp_nvhe(__pkvm_init_vm, host_kvm, hyp_vm, pgd);
154 host_kvm->arch.pkvm.handle = handle;
156 /* Donate memory for the vcpus at hyp and initialize it. */
157 hyp_vcpu_sz = PAGE_ALIGN(PKVM_HYP_VCPU_SIZE);
158 kvm_for_each_vcpu(idx, host_vcpu, host_kvm) {
161 /* Indexing of the vcpus to be sequential starting at 0. */
162 if (WARN_ON(host_vcpu->vcpu_idx != idx)) {
167 hyp_vcpu = alloc_pages_exact(hyp_vcpu_sz, GFP_KERNEL_ACCOUNT);
173 ret = kvm_call_hyp_nvhe(__pkvm_init_vcpu, handle, host_vcpu,
176 free_pages_exact(hyp_vcpu, hyp_vcpu_sz);
184 pkvm_destroy_hyp_vm(host_kvm);
187 free_pages_exact(hyp_vm, hyp_vm_sz);
189 free_pages_exact(pgd, pgd_sz);
193 int pkvm_create_hyp_vm(struct kvm *host_kvm)
197 mutex_lock(&host_kvm->lock);
198 if (!host_kvm->arch.pkvm.handle)
199 ret = __pkvm_create_hyp_vm(host_kvm);
200 mutex_unlock(&host_kvm->lock);
205 void pkvm_destroy_hyp_vm(struct kvm *host_kvm)
207 if (host_kvm->arch.pkvm.handle) {
208 WARN_ON(kvm_call_hyp_nvhe(__pkvm_teardown_vm,
209 host_kvm->arch.pkvm.handle));
212 host_kvm->arch.pkvm.handle = 0;
213 free_hyp_memcache(&host_kvm->arch.pkvm.teardown_mc);
216 int pkvm_init_host_vm(struct kvm *host_kvm)
218 mutex_init(&host_kvm->lock);
222 static void __init _kvm_host_prot_finalize(void *arg)
226 if (WARN_ON(kvm_call_hyp_nvhe(__pkvm_prot_finalize)))
227 WRITE_ONCE(*err, -EINVAL);
230 static int __init pkvm_drop_host_privileges(void)
235 * Flip the static key upfront as that may no longer be possible
236 * once the host stage 2 is installed.
238 static_branch_enable(&kvm_protected_mode_initialized);
239 on_each_cpu(_kvm_host_prot_finalize, &ret, 1);
243 static int __init finalize_pkvm(void)
247 if (!is_protected_kvm_enabled() || !is_kvm_arm_initialised())
251 * Exclude HYP sections from kmemleak so that they don't get peeked
252 * at, which would end badly once inaccessible.
254 kmemleak_free_part(__hyp_bss_start, __hyp_bss_end - __hyp_bss_start);
255 kmemleak_free_part_phys(hyp_mem_base, hyp_mem_size);
257 ret = pkvm_drop_host_privileges();
259 pr_err("Failed to finalize Hyp protection: %d\n", ret);
263 device_initcall_sync(finalize_pkvm);