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285 lines
7.0 KiB
285 lines
7.0 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* Copyright (C) 2020 Google LLC |
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* Author: Quentin Perret <[email protected]> |
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*/ |
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#include <linux/kvm_host.h> |
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#include <asm/kvm_hyp.h> |
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#include <asm/kvm_mmu.h> |
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#include <asm/kvm_pgtable.h> |
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#include <nvhe/early_alloc.h> |
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#include <nvhe/gfp.h> |
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#include <nvhe/memory.h> |
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#include <nvhe/mem_protect.h> |
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#include <nvhe/mm.h> |
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#include <nvhe/trap_handler.h> |
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struct hyp_pool hpool; |
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unsigned long hyp_nr_cpus; |
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#define hyp_percpu_size ((unsigned long)__per_cpu_end - \ |
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(unsigned long)__per_cpu_start) |
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static void *vmemmap_base; |
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static void *hyp_pgt_base; |
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static void *host_s2_pgt_base; |
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static struct kvm_pgtable_mm_ops pkvm_pgtable_mm_ops; |
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static int divide_memory_pool(void *virt, unsigned long size) |
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{ |
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unsigned long vstart, vend, nr_pages; |
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hyp_early_alloc_init(virt, size); |
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hyp_vmemmap_range(__hyp_pa(virt), size, &vstart, &vend); |
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nr_pages = (vend - vstart) >> PAGE_SHIFT; |
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vmemmap_base = hyp_early_alloc_contig(nr_pages); |
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if (!vmemmap_base) |
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return -ENOMEM; |
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nr_pages = hyp_s1_pgtable_pages(); |
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hyp_pgt_base = hyp_early_alloc_contig(nr_pages); |
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if (!hyp_pgt_base) |
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return -ENOMEM; |
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nr_pages = host_s2_pgtable_pages(); |
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host_s2_pgt_base = hyp_early_alloc_contig(nr_pages); |
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if (!host_s2_pgt_base) |
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return -ENOMEM; |
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return 0; |
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} |
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static int recreate_hyp_mappings(phys_addr_t phys, unsigned long size, |
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unsigned long *per_cpu_base, |
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u32 hyp_va_bits) |
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{ |
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void *start, *end, *virt = hyp_phys_to_virt(phys); |
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unsigned long pgt_size = hyp_s1_pgtable_pages() << PAGE_SHIFT; |
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enum kvm_pgtable_prot prot; |
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int ret, i; |
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/* Recreate the hyp page-table using the early page allocator */ |
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hyp_early_alloc_init(hyp_pgt_base, pgt_size); |
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ret = kvm_pgtable_hyp_init(&pkvm_pgtable, hyp_va_bits, |
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&hyp_early_alloc_mm_ops); |
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if (ret) |
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return ret; |
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ret = hyp_create_idmap(hyp_va_bits); |
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if (ret) |
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return ret; |
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ret = hyp_map_vectors(); |
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if (ret) |
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return ret; |
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ret = hyp_back_vmemmap(phys, size, hyp_virt_to_phys(vmemmap_base)); |
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if (ret) |
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return ret; |
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ret = pkvm_create_mappings(__hyp_text_start, __hyp_text_end, PAGE_HYP_EXEC); |
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if (ret) |
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return ret; |
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ret = pkvm_create_mappings(__hyp_rodata_start, __hyp_rodata_end, PAGE_HYP_RO); |
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if (ret) |
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return ret; |
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ret = pkvm_create_mappings(__hyp_bss_start, __hyp_bss_end, PAGE_HYP); |
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if (ret) |
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return ret; |
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ret = pkvm_create_mappings(virt, virt + size, PAGE_HYP); |
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if (ret) |
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return ret; |
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for (i = 0; i < hyp_nr_cpus; i++) { |
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start = (void *)kern_hyp_va(per_cpu_base[i]); |
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end = start + PAGE_ALIGN(hyp_percpu_size); |
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ret = pkvm_create_mappings(start, end, PAGE_HYP); |
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if (ret) |
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return ret; |
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end = (void *)per_cpu_ptr(&kvm_init_params, i)->stack_hyp_va; |
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start = end - PAGE_SIZE; |
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ret = pkvm_create_mappings(start, end, PAGE_HYP); |
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if (ret) |
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return ret; |
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} |
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/* |
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* Map the host's .bss and .rodata sections RO in the hypervisor, but |
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* transfer the ownership from the host to the hypervisor itself to |
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* make sure it can't be donated or shared with another entity. |
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* |
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* The ownership transition requires matching changes in the host |
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* stage-2. This will be done later (see finalize_host_mappings()) once |
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* the hyp_vmemmap is addressable. |
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*/ |
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prot = pkvm_mkstate(PAGE_HYP_RO, PKVM_PAGE_SHARED_OWNED); |
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ret = pkvm_create_mappings(__start_rodata, __end_rodata, prot); |
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if (ret) |
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return ret; |
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ret = pkvm_create_mappings(__hyp_bss_end, __bss_stop, prot); |
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if (ret) |
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return ret; |
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return 0; |
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} |
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static void update_nvhe_init_params(void) |
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{ |
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struct kvm_nvhe_init_params *params; |
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unsigned long i; |
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for (i = 0; i < hyp_nr_cpus; i++) { |
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params = per_cpu_ptr(&kvm_init_params, i); |
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params->pgd_pa = __hyp_pa(pkvm_pgtable.pgd); |
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dcache_clean_inval_poc((unsigned long)params, |
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(unsigned long)params + sizeof(*params)); |
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} |
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} |
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static void *hyp_zalloc_hyp_page(void *arg) |
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{ |
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return hyp_alloc_pages(&hpool, 0); |
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} |
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static void hpool_get_page(void *addr) |
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{ |
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hyp_get_page(&hpool, addr); |
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} |
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static void hpool_put_page(void *addr) |
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{ |
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hyp_put_page(&hpool, addr); |
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} |
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static int finalize_host_mappings_walker(u64 addr, u64 end, u32 level, |
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kvm_pte_t *ptep, |
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enum kvm_pgtable_walk_flags flag, |
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void * const arg) |
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{ |
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enum kvm_pgtable_prot prot; |
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enum pkvm_page_state state; |
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kvm_pte_t pte = *ptep; |
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phys_addr_t phys; |
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if (!kvm_pte_valid(pte)) |
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return 0; |
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if (level != (KVM_PGTABLE_MAX_LEVELS - 1)) |
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return -EINVAL; |
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phys = kvm_pte_to_phys(pte); |
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if (!addr_is_memory(phys)) |
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return 0; |
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/* |
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* Adjust the host stage-2 mappings to match the ownership attributes |
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* configured in the hypervisor stage-1. |
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*/ |
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state = pkvm_getstate(kvm_pgtable_hyp_pte_prot(pte)); |
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switch (state) { |
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case PKVM_PAGE_OWNED: |
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return host_stage2_set_owner_locked(phys, PAGE_SIZE, pkvm_hyp_id); |
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case PKVM_PAGE_SHARED_OWNED: |
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prot = pkvm_mkstate(PKVM_HOST_MEM_PROT, PKVM_PAGE_SHARED_BORROWED); |
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break; |
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case PKVM_PAGE_SHARED_BORROWED: |
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prot = pkvm_mkstate(PKVM_HOST_MEM_PROT, PKVM_PAGE_SHARED_OWNED); |
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break; |
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default: |
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return -EINVAL; |
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} |
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return host_stage2_idmap_locked(phys, PAGE_SIZE, prot); |
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} |
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static int finalize_host_mappings(void) |
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{ |
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struct kvm_pgtable_walker walker = { |
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.cb = finalize_host_mappings_walker, |
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.flags = KVM_PGTABLE_WALK_LEAF, |
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}; |
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return kvm_pgtable_walk(&pkvm_pgtable, 0, BIT(pkvm_pgtable.ia_bits), &walker); |
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} |
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void __noreturn __pkvm_init_finalise(void) |
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{ |
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struct kvm_host_data *host_data = this_cpu_ptr(&kvm_host_data); |
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struct kvm_cpu_context *host_ctxt = &host_data->host_ctxt; |
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unsigned long nr_pages, reserved_pages, pfn; |
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int ret; |
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/* Now that the vmemmap is backed, install the full-fledged allocator */ |
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pfn = hyp_virt_to_pfn(hyp_pgt_base); |
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nr_pages = hyp_s1_pgtable_pages(); |
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reserved_pages = hyp_early_alloc_nr_used_pages(); |
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ret = hyp_pool_init(&hpool, pfn, nr_pages, reserved_pages); |
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if (ret) |
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goto out; |
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ret = kvm_host_prepare_stage2(host_s2_pgt_base); |
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if (ret) |
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goto out; |
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ret = finalize_host_mappings(); |
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if (ret) |
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goto out; |
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pkvm_pgtable_mm_ops = (struct kvm_pgtable_mm_ops) { |
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.zalloc_page = hyp_zalloc_hyp_page, |
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.phys_to_virt = hyp_phys_to_virt, |
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.virt_to_phys = hyp_virt_to_phys, |
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.get_page = hpool_get_page, |
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.put_page = hpool_put_page, |
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}; |
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pkvm_pgtable.mm_ops = &pkvm_pgtable_mm_ops; |
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out: |
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/* |
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* We tail-called to here from handle___pkvm_init() and will not return, |
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* so make sure to propagate the return value to the host. |
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*/ |
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cpu_reg(host_ctxt, 1) = ret; |
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__host_enter(host_ctxt); |
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} |
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int __pkvm_init(phys_addr_t phys, unsigned long size, unsigned long nr_cpus, |
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unsigned long *per_cpu_base, u32 hyp_va_bits) |
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{ |
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struct kvm_nvhe_init_params *params; |
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void *virt = hyp_phys_to_virt(phys); |
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void (*fn)(phys_addr_t params_pa, void *finalize_fn_va); |
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int ret; |
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if (!PAGE_ALIGNED(phys) || !PAGE_ALIGNED(size)) |
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return -EINVAL; |
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hyp_spin_lock_init(&pkvm_pgd_lock); |
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hyp_nr_cpus = nr_cpus; |
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ret = divide_memory_pool(virt, size); |
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if (ret) |
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return ret; |
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ret = recreate_hyp_mappings(phys, size, per_cpu_base, hyp_va_bits); |
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if (ret) |
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return ret; |
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update_nvhe_init_params(); |
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/* Jump in the idmap page to switch to the new page-tables */ |
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params = this_cpu_ptr(&kvm_init_params); |
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fn = (typeof(fn))__hyp_pa(__pkvm_init_switch_pgd); |
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fn(__hyp_pa(params), __pkvm_init_finalise); |
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unreachable(); |
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}
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