// SPDX-License-Identifier: GPL-2.0 /* * Copyright (C) 2020 - Google LLC * Author: Quentin Perret */ #include #include #include #include #include #include #include #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); } static 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); } /* * 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.mmu.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->arch.config_lock); if (!host_kvm->arch.pkvm.handle) ret = __pkvm_create_hyp_vm(host_kvm); mutex_unlock(&host_kvm->arch.config_lock); return ret; } void pkvm_destroy_hyp_vm(struct kvm *host_kvm) { mutex_lock(&host_kvm->arch.config_lock); __pkvm_destroy_hyp_vm(host_kvm); mutex_unlock(&host_kvm->arch.config_lock); } 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);