diff options
Diffstat (limited to 'arch/arm64/kvm/hyp/nvhe/setup.c')
-rw-r--r-- | arch/arm64/kvm/hyp/nvhe/setup.c | 346 |
1 files changed, 346 insertions, 0 deletions
diff --git a/arch/arm64/kvm/hyp/nvhe/setup.c b/arch/arm64/kvm/hyp/nvhe/setup.c new file mode 100644 index 0000000000..0d5e0a89dd --- /dev/null +++ b/arch/arm64/kvm/hyp/nvhe/setup.c @@ -0,0 +1,346 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2020 Google LLC + * Author: Quentin Perret <qperret@google.com> + */ + +#include <linux/kvm_host.h> +#include <asm/kvm_hyp.h> +#include <asm/kvm_mmu.h> +#include <asm/kvm_pgtable.h> +#include <asm/kvm_pkvm.h> + +#include <nvhe/early_alloc.h> +#include <nvhe/ffa.h> +#include <nvhe/fixed_config.h> +#include <nvhe/gfp.h> +#include <nvhe/memory.h> +#include <nvhe/mem_protect.h> +#include <nvhe/mm.h> +#include <nvhe/pkvm.h> +#include <nvhe/trap_handler.h> + +unsigned long hyp_nr_cpus; + +#define hyp_percpu_size ((unsigned long)__per_cpu_end - \ + (unsigned long)__per_cpu_start) + +static void *vmemmap_base; +static void *vm_table_base; +static void *hyp_pgt_base; +static void *host_s2_pgt_base; +static void *ffa_proxy_pages; +static struct kvm_pgtable_mm_ops pkvm_pgtable_mm_ops; +static struct hyp_pool hpool; + +static int divide_memory_pool(void *virt, unsigned long size) +{ + unsigned long nr_pages; + + hyp_early_alloc_init(virt, size); + + nr_pages = hyp_vmemmap_pages(sizeof(struct hyp_page)); + vmemmap_base = hyp_early_alloc_contig(nr_pages); + if (!vmemmap_base) + return -ENOMEM; + + nr_pages = hyp_vm_table_pages(); + vm_table_base = hyp_early_alloc_contig(nr_pages); + if (!vm_table_base) + return -ENOMEM; + + nr_pages = hyp_s1_pgtable_pages(); + hyp_pgt_base = hyp_early_alloc_contig(nr_pages); + if (!hyp_pgt_base) + return -ENOMEM; + + nr_pages = host_s2_pgtable_pages(); + host_s2_pgt_base = hyp_early_alloc_contig(nr_pages); + if (!host_s2_pgt_base) + return -ENOMEM; + + nr_pages = hyp_ffa_proxy_pages(); + ffa_proxy_pages = hyp_early_alloc_contig(nr_pages); + if (!ffa_proxy_pages) + return -ENOMEM; + + return 0; +} + +static int recreate_hyp_mappings(phys_addr_t phys, unsigned long size, + unsigned long *per_cpu_base, + u32 hyp_va_bits) +{ + void *start, *end, *virt = hyp_phys_to_virt(phys); + unsigned long pgt_size = hyp_s1_pgtable_pages() << PAGE_SHIFT; + enum kvm_pgtable_prot prot; + int ret, i; + + /* Recreate the hyp page-table using the early page allocator */ + hyp_early_alloc_init(hyp_pgt_base, pgt_size); + ret = kvm_pgtable_hyp_init(&pkvm_pgtable, hyp_va_bits, + &hyp_early_alloc_mm_ops); + if (ret) + return ret; + + ret = hyp_create_idmap(hyp_va_bits); + if (ret) + return ret; + + ret = hyp_map_vectors(); + if (ret) + return ret; + + ret = hyp_back_vmemmap(hyp_virt_to_phys(vmemmap_base)); + if (ret) + return ret; + + ret = pkvm_create_mappings(__hyp_text_start, __hyp_text_end, PAGE_HYP_EXEC); + if (ret) + return ret; + + ret = pkvm_create_mappings(__hyp_rodata_start, __hyp_rodata_end, PAGE_HYP_RO); + if (ret) + return ret; + + ret = pkvm_create_mappings(__hyp_bss_start, __hyp_bss_end, PAGE_HYP); + if (ret) + return ret; + + ret = pkvm_create_mappings(virt, virt + size, PAGE_HYP); + if (ret) + return ret; + + for (i = 0; i < hyp_nr_cpus; i++) { + struct kvm_nvhe_init_params *params = per_cpu_ptr(&kvm_init_params, i); + + start = (void *)kern_hyp_va(per_cpu_base[i]); + end = start + PAGE_ALIGN(hyp_percpu_size); + ret = pkvm_create_mappings(start, end, PAGE_HYP); + if (ret) + return ret; + + ret = pkvm_create_stack(params->stack_pa, ¶ms->stack_hyp_va); + if (ret) + return ret; + } + + /* + * Map the host sections RO in the hypervisor, but transfer the + * ownership from the host to the hypervisor itself to make sure they + * can't be donated or shared with another entity. + * + * The ownership transition requires matching changes in the host + * stage-2. This will be done later (see finalize_host_mappings()) once + * the hyp_vmemmap is addressable. + */ + prot = pkvm_mkstate(PAGE_HYP_RO, PKVM_PAGE_SHARED_OWNED); + ret = pkvm_create_mappings(&kvm_vgic_global_state, + &kvm_vgic_global_state + 1, prot); + if (ret) + return ret; + + return 0; +} + +static void update_nvhe_init_params(void) +{ + struct kvm_nvhe_init_params *params; + unsigned long i; + + for (i = 0; i < hyp_nr_cpus; i++) { + params = per_cpu_ptr(&kvm_init_params, i); + params->pgd_pa = __hyp_pa(pkvm_pgtable.pgd); + dcache_clean_inval_poc((unsigned long)params, + (unsigned long)params + sizeof(*params)); + } +} + +static void *hyp_zalloc_hyp_page(void *arg) +{ + return hyp_alloc_pages(&hpool, 0); +} + +static void hpool_get_page(void *addr) +{ + hyp_get_page(&hpool, addr); +} + +static void hpool_put_page(void *addr) +{ + hyp_put_page(&hpool, addr); +} + +static int fix_host_ownership_walker(const struct kvm_pgtable_visit_ctx *ctx, + enum kvm_pgtable_walk_flags visit) +{ + enum kvm_pgtable_prot prot; + enum pkvm_page_state state; + phys_addr_t phys; + + if (!kvm_pte_valid(ctx->old)) + return 0; + + if (ctx->level != (KVM_PGTABLE_MAX_LEVELS - 1)) + return -EINVAL; + + phys = kvm_pte_to_phys(ctx->old); + if (!addr_is_memory(phys)) + return -EINVAL; + + /* + * Adjust the host stage-2 mappings to match the ownership attributes + * configured in the hypervisor stage-1. + */ + state = pkvm_getstate(kvm_pgtable_hyp_pte_prot(ctx->old)); + switch (state) { + case PKVM_PAGE_OWNED: + return host_stage2_set_owner_locked(phys, PAGE_SIZE, PKVM_ID_HYP); + case PKVM_PAGE_SHARED_OWNED: + prot = pkvm_mkstate(PKVM_HOST_MEM_PROT, PKVM_PAGE_SHARED_BORROWED); + break; + case PKVM_PAGE_SHARED_BORROWED: + prot = pkvm_mkstate(PKVM_HOST_MEM_PROT, PKVM_PAGE_SHARED_OWNED); + break; + default: + return -EINVAL; + } + + return host_stage2_idmap_locked(phys, PAGE_SIZE, prot); +} + +static int fix_hyp_pgtable_refcnt_walker(const struct kvm_pgtable_visit_ctx *ctx, + enum kvm_pgtable_walk_flags visit) +{ + /* + * Fix-up the refcount for the page-table pages as the early allocator + * was unable to access the hyp_vmemmap and so the buddy allocator has + * initialised the refcount to '1'. + */ + if (kvm_pte_valid(ctx->old)) + ctx->mm_ops->get_page(ctx->ptep); + + return 0; +} + +static int fix_host_ownership(void) +{ + struct kvm_pgtable_walker walker = { + .cb = fix_host_ownership_walker, + .flags = KVM_PGTABLE_WALK_LEAF, + }; + int i, ret; + + for (i = 0; i < hyp_memblock_nr; i++) { + struct memblock_region *reg = &hyp_memory[i]; + u64 start = (u64)hyp_phys_to_virt(reg->base); + + ret = kvm_pgtable_walk(&pkvm_pgtable, start, reg->size, &walker); + if (ret) + return ret; + } + + return 0; +} + +static int fix_hyp_pgtable_refcnt(void) +{ + struct kvm_pgtable_walker walker = { + .cb = fix_hyp_pgtable_refcnt_walker, + .flags = KVM_PGTABLE_WALK_LEAF | KVM_PGTABLE_WALK_TABLE_POST, + .arg = pkvm_pgtable.mm_ops, + }; + + return kvm_pgtable_walk(&pkvm_pgtable, 0, BIT(pkvm_pgtable.ia_bits), + &walker); +} + +void __noreturn __pkvm_init_finalise(void) +{ + struct kvm_host_data *host_data = this_cpu_ptr(&kvm_host_data); + struct kvm_cpu_context *host_ctxt = &host_data->host_ctxt; + unsigned long nr_pages, reserved_pages, pfn; + int ret; + + /* Now that the vmemmap is backed, install the full-fledged allocator */ + pfn = hyp_virt_to_pfn(hyp_pgt_base); + nr_pages = hyp_s1_pgtable_pages(); + reserved_pages = hyp_early_alloc_nr_used_pages(); + ret = hyp_pool_init(&hpool, pfn, nr_pages, reserved_pages); + if (ret) + goto out; + + ret = kvm_host_prepare_stage2(host_s2_pgt_base); + if (ret) + goto out; + + pkvm_pgtable_mm_ops = (struct kvm_pgtable_mm_ops) { + .zalloc_page = hyp_zalloc_hyp_page, + .phys_to_virt = hyp_phys_to_virt, + .virt_to_phys = hyp_virt_to_phys, + .get_page = hpool_get_page, + .put_page = hpool_put_page, + .page_count = hyp_page_count, + }; + pkvm_pgtable.mm_ops = &pkvm_pgtable_mm_ops; + + ret = fix_host_ownership(); + if (ret) + goto out; + + ret = fix_hyp_pgtable_refcnt(); + if (ret) + goto out; + + ret = hyp_create_pcpu_fixmap(); + if (ret) + goto out; + + ret = hyp_ffa_init(ffa_proxy_pages); + if (ret) + goto out; + + pkvm_hyp_vm_table_init(vm_table_base); +out: + /* + * We tail-called to here from handle___pkvm_init() and will not return, + * so make sure to propagate the return value to the host. + */ + cpu_reg(host_ctxt, 1) = ret; + + __host_enter(host_ctxt); +} + +int __pkvm_init(phys_addr_t phys, unsigned long size, unsigned long nr_cpus, + unsigned long *per_cpu_base, u32 hyp_va_bits) +{ + struct kvm_nvhe_init_params *params; + void *virt = hyp_phys_to_virt(phys); + void (*fn)(phys_addr_t params_pa, void *finalize_fn_va); + int ret; + + BUG_ON(kvm_check_pvm_sysreg_table()); + + if (!PAGE_ALIGNED(phys) || !PAGE_ALIGNED(size)) + return -EINVAL; + + hyp_spin_lock_init(&pkvm_pgd_lock); + hyp_nr_cpus = nr_cpus; + + ret = divide_memory_pool(virt, size); + if (ret) + return ret; + + ret = recreate_hyp_mappings(phys, size, per_cpu_base, hyp_va_bits); + if (ret) + return ret; + + update_nvhe_init_params(); + + /* Jump in the idmap page to switch to the new page-tables */ + params = this_cpu_ptr(&kvm_init_params); + fn = (typeof(fn))__hyp_pa(__pkvm_init_switch_pgd); + fn(__hyp_pa(params), __pkvm_init_finalise); + + unreachable(); +} |