| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * Copyright (C) 2020 - Google LLC |
| * Author: Quentin Perret <qperret@google.com> |
| */ |
| |
| #include <linux/init.h> |
| #include <linux/kmemleak.h> |
| #include <linux/kvm_host.h> |
| #include <linux/memblock.h> |
| #include <linux/mutex.h> |
| #include <linux/sort.h> |
| |
| #include <asm/kvm_pkvm.h> |
| |
| #include "hyp_constants.h" |
| |
| DEFINE_STATIC_KEY_FALSE(kvm_protected_mode_initialized); |
| |
| static struct memblock_region *hyp_memory = kvm_nvhe_sym(hyp_memory); |
| static unsigned int *hyp_memblock_nr_ptr = &kvm_nvhe_sym(hyp_memblock_nr); |
| |
| phys_addr_t hyp_mem_base; |
| phys_addr_t hyp_mem_size; |
| |
| static int cmp_hyp_memblock(const void *p1, const void *p2) |
| { |
| const struct memblock_region *r1 = p1; |
| const struct memblock_region *r2 = p2; |
| |
| return r1->base < r2->base ? -1 : (r1->base > r2->base); |
| } |
| |
| static void __init sort_memblock_regions(void) |
| { |
| sort(hyp_memory, |
| *hyp_memblock_nr_ptr, |
| sizeof(struct memblock_region), |
| cmp_hyp_memblock, |
| NULL); |
| } |
| |
| static int __init register_memblock_regions(void) |
| { |
| struct memblock_region *reg; |
| |
| for_each_mem_region(reg) { |
| if (*hyp_memblock_nr_ptr >= HYP_MEMBLOCK_REGIONS) |
| return -ENOMEM; |
| |
| hyp_memory[*hyp_memblock_nr_ptr] = *reg; |
| (*hyp_memblock_nr_ptr)++; |
| } |
| sort_memblock_regions(); |
| |
| return 0; |
| } |
| |
| void __init kvm_hyp_reserve(void) |
| { |
| u64 hyp_mem_pages = 0; |
| int ret; |
| |
| if (!is_hyp_mode_available() || is_kernel_in_hyp_mode()) |
| return; |
| |
| if (kvm_get_mode() != KVM_MODE_PROTECTED) |
| return; |
| |
| ret = register_memblock_regions(); |
| if (ret) { |
| *hyp_memblock_nr_ptr = 0; |
| kvm_err("Failed to register hyp memblocks: %d\n", ret); |
| return; |
| } |
| |
| hyp_mem_pages += hyp_s1_pgtable_pages(); |
| hyp_mem_pages += host_s2_pgtable_pages(); |
| hyp_mem_pages += hyp_vm_table_pages(); |
| hyp_mem_pages += hyp_vmemmap_pages(STRUCT_HYP_PAGE_SIZE); |
| hyp_mem_pages += hyp_ffa_proxy_pages(); |
| |
| /* |
| * Try to allocate a PMD-aligned region to reduce TLB pressure once |
| * this is unmapped from the host stage-2, and fallback to PAGE_SIZE. |
| */ |
| hyp_mem_size = hyp_mem_pages << PAGE_SHIFT; |
| hyp_mem_base = memblock_phys_alloc(ALIGN(hyp_mem_size, PMD_SIZE), |
| PMD_SIZE); |
| if (!hyp_mem_base) |
| hyp_mem_base = memblock_phys_alloc(hyp_mem_size, PAGE_SIZE); |
| else |
| hyp_mem_size = ALIGN(hyp_mem_size, PMD_SIZE); |
| |
| if (!hyp_mem_base) { |
| kvm_err("Failed to reserve hyp memory\n"); |
| return; |
| } |
| |
| kvm_info("Reserved %lld MiB at 0x%llx\n", hyp_mem_size >> 20, |
| hyp_mem_base); |
| } |
| |
| /* |
| * Allocates and donates memory for hypervisor VM structs at EL2. |
| * |
| * Allocates space for the VM state, which includes the hyp vm as well as |
| * the hyp vcpus. |
| * |
| * Stores an opaque handler in the kvm struct for future reference. |
| * |
| * Return 0 on success, negative error code on failure. |
| */ |
| static int __pkvm_create_hyp_vm(struct kvm *host_kvm) |
| { |
| size_t pgd_sz, hyp_vm_sz, hyp_vcpu_sz; |
| struct kvm_vcpu *host_vcpu; |
| pkvm_handle_t handle; |
| void *pgd, *hyp_vm; |
| unsigned long idx; |
| int ret; |
| |
| if (host_kvm->created_vcpus < 1) |
| return -EINVAL; |
| |
| pgd_sz = kvm_pgtable_stage2_pgd_size(host_kvm->arch.vtcr); |
| |
| /* |
| * The PGD pages will be reclaimed using a hyp_memcache which implies |
| * page granularity. So, use alloc_pages_exact() to get individual |
| * refcounts. |
| */ |
| pgd = alloc_pages_exact(pgd_sz, GFP_KERNEL_ACCOUNT); |
| if (!pgd) |
| return -ENOMEM; |
| |
| /* Allocate memory to donate to hyp for vm and vcpu pointers. */ |
| hyp_vm_sz = PAGE_ALIGN(size_add(PKVM_HYP_VM_SIZE, |
| size_mul(sizeof(void *), |
| host_kvm->created_vcpus))); |
| hyp_vm = alloc_pages_exact(hyp_vm_sz, GFP_KERNEL_ACCOUNT); |
| if (!hyp_vm) { |
| ret = -ENOMEM; |
| goto free_pgd; |
| } |
| |
| /* Donate the VM memory to hyp and let hyp initialize it. */ |
| ret = kvm_call_hyp_nvhe(__pkvm_init_vm, host_kvm, hyp_vm, pgd); |
| if (ret < 0) |
| goto free_vm; |
| |
| handle = ret; |
| |
| host_kvm->arch.pkvm.handle = handle; |
| |
| /* Donate memory for the vcpus at hyp and initialize it. */ |
| hyp_vcpu_sz = PAGE_ALIGN(PKVM_HYP_VCPU_SIZE); |
| kvm_for_each_vcpu(idx, host_vcpu, host_kvm) { |
| void *hyp_vcpu; |
| |
| /* Indexing of the vcpus to be sequential starting at 0. */ |
| if (WARN_ON(host_vcpu->vcpu_idx != idx)) { |
| ret = -EINVAL; |
| goto destroy_vm; |
| } |
| |
| hyp_vcpu = alloc_pages_exact(hyp_vcpu_sz, GFP_KERNEL_ACCOUNT); |
| if (!hyp_vcpu) { |
| ret = -ENOMEM; |
| goto destroy_vm; |
| } |
| |
| ret = kvm_call_hyp_nvhe(__pkvm_init_vcpu, handle, host_vcpu, |
| hyp_vcpu); |
| if (ret) { |
| free_pages_exact(hyp_vcpu, hyp_vcpu_sz); |
| goto destroy_vm; |
| } |
| } |
| |
| return 0; |
| |
| destroy_vm: |
| pkvm_destroy_hyp_vm(host_kvm); |
| return ret; |
| free_vm: |
| free_pages_exact(hyp_vm, hyp_vm_sz); |
| free_pgd: |
| free_pages_exact(pgd, pgd_sz); |
| return ret; |
| } |
| |
| int pkvm_create_hyp_vm(struct kvm *host_kvm) |
| { |
| int ret = 0; |
| |
| mutex_lock(&host_kvm->lock); |
| if (!host_kvm->arch.pkvm.handle) |
| ret = __pkvm_create_hyp_vm(host_kvm); |
| mutex_unlock(&host_kvm->lock); |
| |
| return ret; |
| } |
| |
| void pkvm_destroy_hyp_vm(struct kvm *host_kvm) |
| { |
| if (host_kvm->arch.pkvm.handle) { |
| WARN_ON(kvm_call_hyp_nvhe(__pkvm_teardown_vm, |
| host_kvm->arch.pkvm.handle)); |
| } |
| |
| host_kvm->arch.pkvm.handle = 0; |
| free_hyp_memcache(&host_kvm->arch.pkvm.teardown_mc); |
| } |
| |
| int pkvm_init_host_vm(struct kvm *host_kvm) |
| { |
| mutex_init(&host_kvm->lock); |
| return 0; |
| } |
| |
| static void __init _kvm_host_prot_finalize(void *arg) |
| { |
| int *err = arg; |
| |
| if (WARN_ON(kvm_call_hyp_nvhe(__pkvm_prot_finalize))) |
| WRITE_ONCE(*err, -EINVAL); |
| } |
| |
| static int __init pkvm_drop_host_privileges(void) |
| { |
| int ret = 0; |
| |
| /* |
| * Flip the static key upfront as that may no longer be possible |
| * once the host stage 2 is installed. |
| */ |
| static_branch_enable(&kvm_protected_mode_initialized); |
| on_each_cpu(_kvm_host_prot_finalize, &ret, 1); |
| return ret; |
| } |
| |
| static int __init finalize_pkvm(void) |
| { |
| int ret; |
| |
| if (!is_protected_kvm_enabled() || !is_kvm_arm_initialised()) |
| return 0; |
| |
| /* |
| * Exclude HYP sections from kmemleak so that they don't get peeked |
| * at, which would end badly once inaccessible. |
| */ |
| kmemleak_free_part(__hyp_bss_start, __hyp_bss_end - __hyp_bss_start); |
| kmemleak_free_part_phys(hyp_mem_base, hyp_mem_size); |
| |
| ret = pkvm_drop_host_privileges(); |
| if (ret) |
| pr_err("Failed to finalize Hyp protection: %d\n", ret); |
| |
| return ret; |
| } |
| device_initcall_sync(finalize_pkvm); |