2020-10-15 02:26:43 +08:00
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// SPDX-License-Identifier: GPL-2.0
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2020-10-15 02:26:44 +08:00
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#include "mmu.h"
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#include "mmu_internal.h"
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2020-10-15 02:26:50 +08:00
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#include "mmutrace.h"
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2020-10-15 02:26:45 +08:00
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#include "tdp_iter.h"
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2020-10-15 02:26:43 +08:00
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#include "tdp_mmu.h"
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2020-10-15 02:26:44 +08:00
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#include "spte.h"
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2020-10-15 02:26:43 +08:00
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2020-10-15 02:26:58 +08:00
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#ifdef CONFIG_X86_64
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2020-10-15 02:26:43 +08:00
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static bool __read_mostly tdp_mmu_enabled = false;
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2020-10-15 02:26:58 +08:00
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module_param_named(tdp_mmu, tdp_mmu_enabled, bool, 0644);
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#endif
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2020-10-15 02:26:43 +08:00
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static bool is_tdp_mmu_enabled(void)
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{
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#ifdef CONFIG_X86_64
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return tdp_enabled && READ_ONCE(tdp_mmu_enabled);
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#else
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return false;
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#endif /* CONFIG_X86_64 */
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}
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/* Initializes the TDP MMU for the VM, if enabled. */
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void kvm_mmu_init_tdp_mmu(struct kvm *kvm)
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{
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if (!is_tdp_mmu_enabled())
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return;
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/* This should not be changed for the lifetime of the VM. */
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kvm->arch.tdp_mmu_enabled = true;
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2020-10-15 02:26:44 +08:00
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INIT_LIST_HEAD(&kvm->arch.tdp_mmu_roots);
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2020-10-15 02:26:51 +08:00
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INIT_LIST_HEAD(&kvm->arch.tdp_mmu_pages);
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2020-10-15 02:26:43 +08:00
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}
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void kvm_mmu_uninit_tdp_mmu(struct kvm *kvm)
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{
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if (!kvm->arch.tdp_mmu_enabled)
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return;
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2020-10-15 02:26:44 +08:00
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WARN_ON(!list_empty(&kvm->arch.tdp_mmu_roots));
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}
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#define for_each_tdp_mmu_root(_kvm, _root) \
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list_for_each_entry(_root, &_kvm->arch.tdp_mmu_roots, link)
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bool is_tdp_mmu_root(struct kvm *kvm, hpa_t hpa)
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{
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struct kvm_mmu_page *sp;
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2020-11-15 21:55:43 +08:00
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if (!kvm->arch.tdp_mmu_enabled)
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return false;
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if (WARN_ON(!VALID_PAGE(hpa)))
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return false;
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2020-10-15 02:26:44 +08:00
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sp = to_shadow_page(hpa);
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2020-11-15 21:55:43 +08:00
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if (WARN_ON(!sp))
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return false;
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2020-10-15 02:26:44 +08:00
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return sp->tdp_mmu_page && sp->root_count;
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}
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2020-10-15 02:26:47 +08:00
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static bool zap_gfn_range(struct kvm *kvm, struct kvm_mmu_page *root,
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2020-10-15 02:26:52 +08:00
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gfn_t start, gfn_t end, bool can_yield);
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2020-10-15 02:26:47 +08:00
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2020-10-15 02:26:44 +08:00
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void kvm_tdp_mmu_free_root(struct kvm *kvm, struct kvm_mmu_page *root)
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{
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2020-12-04 07:11:20 +08:00
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gfn_t max_gfn = 1ULL << (shadow_phys_bits - PAGE_SHIFT);
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2020-10-15 02:26:47 +08:00
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2020-10-15 02:26:44 +08:00
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lockdep_assert_held(&kvm->mmu_lock);
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WARN_ON(root->root_count);
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WARN_ON(!root->tdp_mmu_page);
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list_del(&root->link);
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2020-10-15 02:26:52 +08:00
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zap_gfn_range(kvm, root, 0, max_gfn, false);
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2020-10-15 02:26:47 +08:00
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2020-10-15 02:26:44 +08:00
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free_page((unsigned long)root->spt);
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kmem_cache_free(mmu_page_header_cache, root);
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}
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static union kvm_mmu_page_role page_role_for_level(struct kvm_vcpu *vcpu,
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int level)
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{
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union kvm_mmu_page_role role;
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role = vcpu->arch.mmu->mmu_role.base;
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role.level = level;
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role.direct = true;
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role.gpte_is_8_bytes = true;
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role.access = ACC_ALL;
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return role;
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}
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static struct kvm_mmu_page *alloc_tdp_mmu_page(struct kvm_vcpu *vcpu, gfn_t gfn,
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int level)
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{
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struct kvm_mmu_page *sp;
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sp = kvm_mmu_memory_cache_alloc(&vcpu->arch.mmu_page_header_cache);
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sp->spt = kvm_mmu_memory_cache_alloc(&vcpu->arch.mmu_shadow_page_cache);
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set_page_private(virt_to_page(sp->spt), (unsigned long)sp);
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sp->role.word = page_role_for_level(vcpu, level).word;
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sp->gfn = gfn;
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sp->tdp_mmu_page = true;
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return sp;
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}
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static struct kvm_mmu_page *get_tdp_mmu_vcpu_root(struct kvm_vcpu *vcpu)
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{
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union kvm_mmu_page_role role;
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struct kvm *kvm = vcpu->kvm;
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struct kvm_mmu_page *root;
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role = page_role_for_level(vcpu, vcpu->arch.mmu->shadow_root_level);
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spin_lock(&kvm->mmu_lock);
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/* Check for an existing root before allocating a new one. */
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for_each_tdp_mmu_root(kvm, root) {
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if (root->role.word == role.word) {
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kvm_mmu_get_root(kvm, root);
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spin_unlock(&kvm->mmu_lock);
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return root;
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}
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}
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root = alloc_tdp_mmu_page(vcpu, 0, vcpu->arch.mmu->shadow_root_level);
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root->root_count = 1;
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list_add(&root->link, &kvm->arch.tdp_mmu_roots);
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spin_unlock(&kvm->mmu_lock);
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return root;
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}
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hpa_t kvm_tdp_mmu_get_vcpu_root_hpa(struct kvm_vcpu *vcpu)
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{
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struct kvm_mmu_page *root;
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root = get_tdp_mmu_vcpu_root(vcpu);
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if (!root)
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return INVALID_PAGE;
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return __pa(root->spt);
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2020-10-15 02:26:43 +08:00
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}
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2020-10-15 02:26:45 +08:00
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static void handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn,
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u64 old_spte, u64 new_spte, int level);
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2020-10-15 02:26:47 +08:00
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static int kvm_mmu_page_as_id(struct kvm_mmu_page *sp)
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{
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return sp->role.smm ? 1 : 0;
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}
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2020-10-15 02:26:53 +08:00
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static void handle_changed_spte_acc_track(u64 old_spte, u64 new_spte, int level)
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{
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bool pfn_changed = spte_to_pfn(old_spte) != spte_to_pfn(new_spte);
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if (!is_shadow_present_pte(old_spte) || !is_last_spte(old_spte, level))
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return;
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if (is_accessed_spte(old_spte) &&
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(!is_accessed_spte(new_spte) || pfn_changed))
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kvm_set_pfn_accessed(spte_to_pfn(old_spte));
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}
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2020-10-15 02:26:55 +08:00
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static void handle_changed_spte_dirty_log(struct kvm *kvm, int as_id, gfn_t gfn,
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u64 old_spte, u64 new_spte, int level)
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{
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bool pfn_changed;
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struct kvm_memory_slot *slot;
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if (level > PG_LEVEL_4K)
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return;
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pfn_changed = spte_to_pfn(old_spte) != spte_to_pfn(new_spte);
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if ((!is_writable_pte(old_spte) || pfn_changed) &&
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is_writable_pte(new_spte)) {
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slot = __gfn_to_memslot(__kvm_memslots(kvm, as_id), gfn);
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mark_page_dirty_in_slot(slot, gfn);
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}
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}
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2020-10-15 02:26:45 +08:00
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/**
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* handle_changed_spte - handle bookkeeping associated with an SPTE change
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* @kvm: kvm instance
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* @as_id: the address space of the paging structure the SPTE was a part of
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* @gfn: the base GFN that was mapped by the SPTE
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* @old_spte: The value of the SPTE before the change
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* @new_spte: The value of the SPTE after the change
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* @level: the level of the PT the SPTE is part of in the paging structure
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*
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* Handle bookkeeping that might result from the modification of a SPTE.
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* This function must be called for all TDP SPTE modifications.
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*/
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static void __handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn,
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u64 old_spte, u64 new_spte, int level)
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{
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bool was_present = is_shadow_present_pte(old_spte);
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bool is_present = is_shadow_present_pte(new_spte);
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bool was_leaf = was_present && is_last_spte(old_spte, level);
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bool is_leaf = is_present && is_last_spte(new_spte, level);
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bool pfn_changed = spte_to_pfn(old_spte) != spte_to_pfn(new_spte);
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u64 *pt;
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2020-10-15 02:26:51 +08:00
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struct kvm_mmu_page *sp;
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2020-10-15 02:26:45 +08:00
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u64 old_child_spte;
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int i;
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WARN_ON(level > PT64_ROOT_MAX_LEVEL);
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WARN_ON(level < PG_LEVEL_4K);
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2020-10-24 11:11:50 +08:00
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WARN_ON(gfn & (KVM_PAGES_PER_HPAGE(level) - 1));
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2020-10-15 02:26:45 +08:00
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/*
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* If this warning were to trigger it would indicate that there was a
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* missing MMU notifier or a race with some notifier handler.
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* A present, leaf SPTE should never be directly replaced with another
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* present leaf SPTE pointing to a differnt PFN. A notifier handler
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* should be zapping the SPTE before the main MM's page table is
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* changed, or the SPTE should be zeroed, and the TLBs flushed by the
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* thread before replacement.
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*/
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if (was_leaf && is_leaf && pfn_changed) {
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pr_err("Invalid SPTE change: cannot replace a present leaf\n"
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"SPTE with another present leaf SPTE mapping a\n"
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"different PFN!\n"
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"as_id: %d gfn: %llx old_spte: %llx new_spte: %llx level: %d",
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as_id, gfn, old_spte, new_spte, level);
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/*
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* Crash the host to prevent error propagation and guest data
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* courruption.
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*/
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BUG();
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}
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if (old_spte == new_spte)
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return;
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/*
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* The only times a SPTE should be changed from a non-present to
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* non-present state is when an MMIO entry is installed/modified/
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* removed. In that case, there is nothing to do here.
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*/
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if (!was_present && !is_present) {
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/*
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* If this change does not involve a MMIO SPTE, it is
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* unexpected. Log the change, though it should not impact the
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* guest since both the former and current SPTEs are nonpresent.
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*/
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if (WARN_ON(!is_mmio_spte(old_spte) && !is_mmio_spte(new_spte)))
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pr_err("Unexpected SPTE change! Nonpresent SPTEs\n"
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"should not be replaced with another,\n"
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"different nonpresent SPTE, unless one or both\n"
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"are MMIO SPTEs.\n"
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"as_id: %d gfn: %llx old_spte: %llx new_spte: %llx level: %d",
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as_id, gfn, old_spte, new_spte, level);
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return;
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}
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if (was_leaf && is_dirty_spte(old_spte) &&
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(!is_dirty_spte(new_spte) || pfn_changed))
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kvm_set_pfn_dirty(spte_to_pfn(old_spte));
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/*
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* Recursively handle child PTs if the change removed a subtree from
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* the paging structure.
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*/
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if (was_present && !was_leaf && (pfn_changed || !is_present)) {
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pt = spte_to_child_pt(old_spte, level);
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2020-10-15 02:26:51 +08:00
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sp = sptep_to_sp(pt);
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list_del(&sp->link);
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2020-10-15 02:26:45 +08:00
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2020-10-15 02:27:00 +08:00
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if (sp->lpage_disallowed)
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unaccount_huge_nx_page(kvm, sp);
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2020-10-15 02:26:45 +08:00
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for (i = 0; i < PT64_ENT_PER_PAGE; i++) {
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old_child_spte = READ_ONCE(*(pt + i));
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WRITE_ONCE(*(pt + i), 0);
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handle_changed_spte(kvm, as_id,
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gfn + (i * KVM_PAGES_PER_HPAGE(level - 1)),
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old_child_spte, 0, level - 1);
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}
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kvm_flush_remote_tlbs_with_address(kvm, gfn,
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KVM_PAGES_PER_HPAGE(level));
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free_page((unsigned long)pt);
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2020-10-15 02:26:51 +08:00
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kmem_cache_free(mmu_page_header_cache, sp);
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2020-10-15 02:26:45 +08:00
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}
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}
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static void handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn,
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u64 old_spte, u64 new_spte, int level)
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{
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__handle_changed_spte(kvm, as_id, gfn, old_spte, new_spte, level);
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2020-10-15 02:26:53 +08:00
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handle_changed_spte_acc_track(old_spte, new_spte, level);
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2020-10-15 02:26:55 +08:00
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handle_changed_spte_dirty_log(kvm, as_id, gfn, old_spte,
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new_spte, level);
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2020-10-15 02:26:45 +08:00
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}
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2020-10-15 02:26:47 +08:00
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2020-10-15 02:26:53 +08:00
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static inline void __tdp_mmu_set_spte(struct kvm *kvm, struct tdp_iter *iter,
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2020-10-15 02:26:55 +08:00
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u64 new_spte, bool record_acc_track,
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bool record_dirty_log)
|
2020-10-15 02:26:47 +08:00
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{
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u64 *root_pt = tdp_iter_root_pt(iter);
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struct kvm_mmu_page *root = sptep_to_sp(root_pt);
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int as_id = kvm_mmu_page_as_id(root);
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2020-10-15 02:26:53 +08:00
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WRITE_ONCE(*iter->sptep, new_spte);
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__handle_changed_spte(kvm, as_id, iter->gfn, iter->old_spte, new_spte,
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iter->level);
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if (record_acc_track)
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handle_changed_spte_acc_track(iter->old_spte, new_spte,
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iter->level);
|
2020-10-15 02:26:55 +08:00
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if (record_dirty_log)
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handle_changed_spte_dirty_log(kvm, as_id, iter->gfn,
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iter->old_spte, new_spte,
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iter->level);
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2020-10-15 02:26:53 +08:00
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}
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static inline void tdp_mmu_set_spte(struct kvm *kvm, struct tdp_iter *iter,
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u64 new_spte)
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{
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2020-10-15 02:26:55 +08:00
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__tdp_mmu_set_spte(kvm, iter, new_spte, true, true);
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2020-10-15 02:26:53 +08:00
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}
|
2020-10-15 02:26:47 +08:00
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|
2020-10-15 02:26:53 +08:00
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static inline void tdp_mmu_set_spte_no_acc_track(struct kvm *kvm,
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struct tdp_iter *iter,
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u64 new_spte)
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{
|
2020-10-15 02:26:55 +08:00
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__tdp_mmu_set_spte(kvm, iter, new_spte, false, true);
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}
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static inline void tdp_mmu_set_spte_no_dirty_log(struct kvm *kvm,
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struct tdp_iter *iter,
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u64 new_spte)
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{
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__tdp_mmu_set_spte(kvm, iter, new_spte, true, false);
|
2020-10-15 02:26:47 +08:00
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}
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#define tdp_root_for_each_pte(_iter, _root, _start, _end) \
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for_each_tdp_pte(_iter, _root->spt, _root->role.level, _start, _end)
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|
2020-10-15 02:26:53 +08:00
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#define tdp_root_for_each_leaf_pte(_iter, _root, _start, _end) \
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tdp_root_for_each_pte(_iter, _root, _start, _end) \
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if (!is_shadow_present_pte(_iter.old_spte) || \
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!is_last_spte(_iter.old_spte, _iter.level)) \
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continue; \
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else
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|
2020-10-15 02:26:50 +08:00
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#define tdp_mmu_for_each_pte(_iter, _mmu, _start, _end) \
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for_each_tdp_pte(_iter, __va(_mmu->root_hpa), \
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_mmu->shadow_root_level, _start, _end)
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|
2020-10-15 02:26:47 +08:00
|
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/*
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* Flush the TLB if the process should drop kvm->mmu_lock.
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* Return whether the caller still needs to flush the tlb.
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*/
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static bool tdp_mmu_iter_flush_cond_resched(struct kvm *kvm, struct tdp_iter *iter)
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{
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if (need_resched() || spin_needbreak(&kvm->mmu_lock)) {
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kvm_flush_remote_tlbs(kvm);
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cond_resched_lock(&kvm->mmu_lock);
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tdp_iter_refresh_walk(iter);
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return false;
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} else {
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return true;
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}
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}
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|
2020-10-15 02:26:55 +08:00
|
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static void tdp_mmu_iter_cond_resched(struct kvm *kvm, struct tdp_iter *iter)
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{
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if (need_resched() || spin_needbreak(&kvm->mmu_lock)) {
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cond_resched_lock(&kvm->mmu_lock);
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tdp_iter_refresh_walk(iter);
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}
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}
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|
|
|
|
2020-10-15 02:26:47 +08:00
|
|
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/*
|
|
|
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* Tears down the mappings for the range of gfns, [start, end), and frees the
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|
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* non-root pages mapping GFNs strictly within that range. Returns true if
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|
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* SPTEs have been cleared and a TLB flush is needed before releasing the
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|
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* MMU lock.
|
2020-10-15 02:26:52 +08:00
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* If can_yield is true, will release the MMU lock and reschedule if the
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|
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* scheduler needs the CPU or there is contention on the MMU lock. If this
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|
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* function cannot yield, it will not release the MMU lock or reschedule and
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* the caller must ensure it does not supply too large a GFN range, or the
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* operation can cause a soft lockup.
|
2020-10-15 02:26:47 +08:00
|
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|
*/
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|
static bool zap_gfn_range(struct kvm *kvm, struct kvm_mmu_page *root,
|
2020-10-15 02:26:52 +08:00
|
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|
gfn_t start, gfn_t end, bool can_yield)
|
2020-10-15 02:26:47 +08:00
|
|
|
{
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|
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|
struct tdp_iter iter;
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|
bool flush_needed = false;
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tdp_root_for_each_pte(iter, root, start, end) {
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if (!is_shadow_present_pte(iter.old_spte))
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|
continue;
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/*
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* If this is a non-last-level SPTE that covers a larger range
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* than should be zapped, continue, and zap the mappings at a
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* lower level.
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|
*/
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|
if ((iter.gfn < start ||
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|
iter.gfn + KVM_PAGES_PER_HPAGE(iter.level) > end) &&
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|
!is_last_spte(iter.old_spte, iter.level))
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|
|
|
continue;
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|
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|
tdp_mmu_set_spte(kvm, &iter, 0);
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|
|
|
2020-10-15 02:26:52 +08:00
|
|
|
if (can_yield)
|
|
|
|
flush_needed = tdp_mmu_iter_flush_cond_resched(kvm, &iter);
|
|
|
|
else
|
|
|
|
flush_needed = true;
|
2020-10-15 02:26:47 +08:00
|
|
|
}
|
|
|
|
return flush_needed;
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Tears down the mappings for the range of gfns, [start, end), and frees the
|
|
|
|
* non-root pages mapping GFNs strictly within that range. Returns true if
|
|
|
|
* SPTEs have been cleared and a TLB flush is needed before releasing the
|
|
|
|
* MMU lock.
|
|
|
|
*/
|
|
|
|
bool kvm_tdp_mmu_zap_gfn_range(struct kvm *kvm, gfn_t start, gfn_t end)
|
|
|
|
{
|
|
|
|
struct kvm_mmu_page *root;
|
|
|
|
bool flush = false;
|
|
|
|
|
|
|
|
for_each_tdp_mmu_root(kvm, root) {
|
|
|
|
/*
|
|
|
|
* Take a reference on the root so that it cannot be freed if
|
|
|
|
* this thread releases the MMU lock and yields in this loop.
|
|
|
|
*/
|
|
|
|
kvm_mmu_get_root(kvm, root);
|
|
|
|
|
2020-10-15 02:26:52 +08:00
|
|
|
flush |= zap_gfn_range(kvm, root, start, end, true);
|
2020-10-15 02:26:47 +08:00
|
|
|
|
|
|
|
kvm_mmu_put_root(kvm, root);
|
|
|
|
}
|
|
|
|
|
|
|
|
return flush;
|
|
|
|
}
|
|
|
|
|
|
|
|
void kvm_tdp_mmu_zap_all(struct kvm *kvm)
|
|
|
|
{
|
2020-12-04 07:11:20 +08:00
|
|
|
gfn_t max_gfn = 1ULL << (shadow_phys_bits - PAGE_SHIFT);
|
2020-10-15 02:26:47 +08:00
|
|
|
bool flush;
|
|
|
|
|
|
|
|
flush = kvm_tdp_mmu_zap_gfn_range(kvm, 0, max_gfn);
|
|
|
|
if (flush)
|
|
|
|
kvm_flush_remote_tlbs(kvm);
|
|
|
|
}
|
2020-10-15 02:26:50 +08:00
|
|
|
|
|
|
|
/*
|
|
|
|
* Installs a last-level SPTE to handle a TDP page fault.
|
|
|
|
* (NPT/EPT violation/misconfiguration)
|
|
|
|
*/
|
|
|
|
static int tdp_mmu_map_handle_target_level(struct kvm_vcpu *vcpu, int write,
|
|
|
|
int map_writable,
|
|
|
|
struct tdp_iter *iter,
|
|
|
|
kvm_pfn_t pfn, bool prefault)
|
|
|
|
{
|
|
|
|
u64 new_spte;
|
|
|
|
int ret = 0;
|
|
|
|
int make_spte_ret = 0;
|
|
|
|
|
|
|
|
if (unlikely(is_noslot_pfn(pfn))) {
|
|
|
|
new_spte = make_mmio_spte(vcpu, iter->gfn, ACC_ALL);
|
|
|
|
trace_mark_mmio_spte(iter->sptep, iter->gfn, new_spte);
|
|
|
|
} else
|
|
|
|
make_spte_ret = make_spte(vcpu, ACC_ALL, iter->level, iter->gfn,
|
|
|
|
pfn, iter->old_spte, prefault, true,
|
|
|
|
map_writable, !shadow_accessed_mask,
|
|
|
|
&new_spte);
|
|
|
|
|
|
|
|
if (new_spte == iter->old_spte)
|
|
|
|
ret = RET_PF_SPURIOUS;
|
|
|
|
else
|
|
|
|
tdp_mmu_set_spte(vcpu->kvm, iter, new_spte);
|
|
|
|
|
|
|
|
/*
|
|
|
|
* If the page fault was caused by a write but the page is write
|
|
|
|
* protected, emulation is needed. If the emulation was skipped,
|
|
|
|
* the vCPU would have the same fault again.
|
|
|
|
*/
|
|
|
|
if (make_spte_ret & SET_SPTE_WRITE_PROTECTED_PT) {
|
|
|
|
if (write)
|
|
|
|
ret = RET_PF_EMULATE;
|
|
|
|
kvm_make_request(KVM_REQ_TLB_FLUSH_CURRENT, vcpu);
|
|
|
|
}
|
|
|
|
|
|
|
|
/* If a MMIO SPTE is installed, the MMIO will need to be emulated. */
|
|
|
|
if (unlikely(is_mmio_spte(new_spte)))
|
|
|
|
ret = RET_PF_EMULATE;
|
|
|
|
|
|
|
|
trace_kvm_mmu_set_spte(iter->level, iter->gfn, iter->sptep);
|
|
|
|
if (!prefault)
|
|
|
|
vcpu->stat.pf_fixed++;
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Handle a TDP page fault (NPT/EPT violation/misconfiguration) by installing
|
|
|
|
* page tables and SPTEs to translate the faulting guest physical address.
|
|
|
|
*/
|
|
|
|
int kvm_tdp_mmu_map(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code,
|
|
|
|
int map_writable, int max_level, kvm_pfn_t pfn,
|
|
|
|
bool prefault)
|
|
|
|
{
|
|
|
|
bool nx_huge_page_workaround_enabled = is_nx_huge_page_enabled();
|
|
|
|
bool write = error_code & PFERR_WRITE_MASK;
|
|
|
|
bool exec = error_code & PFERR_FETCH_MASK;
|
|
|
|
bool huge_page_disallowed = exec && nx_huge_page_workaround_enabled;
|
|
|
|
struct kvm_mmu *mmu = vcpu->arch.mmu;
|
|
|
|
struct tdp_iter iter;
|
2020-10-15 02:26:51 +08:00
|
|
|
struct kvm_mmu_page *sp;
|
2020-10-15 02:26:50 +08:00
|
|
|
u64 *child_pt;
|
|
|
|
u64 new_spte;
|
|
|
|
int ret;
|
|
|
|
gfn_t gfn = gpa >> PAGE_SHIFT;
|
|
|
|
int level;
|
|
|
|
int req_level;
|
|
|
|
|
|
|
|
if (WARN_ON(!VALID_PAGE(vcpu->arch.mmu->root_hpa)))
|
|
|
|
return RET_PF_RETRY;
|
|
|
|
if (WARN_ON(!is_tdp_mmu_root(vcpu->kvm, vcpu->arch.mmu->root_hpa)))
|
|
|
|
return RET_PF_RETRY;
|
|
|
|
|
|
|
|
level = kvm_mmu_hugepage_adjust(vcpu, gfn, max_level, &pfn,
|
|
|
|
huge_page_disallowed, &req_level);
|
|
|
|
|
|
|
|
trace_kvm_mmu_spte_requested(gpa, level, pfn);
|
|
|
|
tdp_mmu_for_each_pte(iter, mmu, gfn, gfn + 1) {
|
|
|
|
if (nx_huge_page_workaround_enabled)
|
|
|
|
disallowed_hugepage_adjust(iter.old_spte, gfn,
|
|
|
|
iter.level, &pfn, &level);
|
|
|
|
|
|
|
|
if (iter.level == level)
|
|
|
|
break;
|
|
|
|
|
|
|
|
/*
|
|
|
|
* If there is an SPTE mapping a large page at a higher level
|
|
|
|
* than the target, that SPTE must be cleared and replaced
|
|
|
|
* with a non-leaf SPTE.
|
|
|
|
*/
|
|
|
|
if (is_shadow_present_pte(iter.old_spte) &&
|
|
|
|
is_large_pte(iter.old_spte)) {
|
|
|
|
tdp_mmu_set_spte(vcpu->kvm, &iter, 0);
|
|
|
|
|
|
|
|
kvm_flush_remote_tlbs_with_address(vcpu->kvm, iter.gfn,
|
|
|
|
KVM_PAGES_PER_HPAGE(iter.level));
|
|
|
|
|
|
|
|
/*
|
|
|
|
* The iter must explicitly re-read the spte here
|
|
|
|
* because the new value informs the !present
|
|
|
|
* path below.
|
|
|
|
*/
|
|
|
|
iter.old_spte = READ_ONCE(*iter.sptep);
|
|
|
|
}
|
|
|
|
|
|
|
|
if (!is_shadow_present_pte(iter.old_spte)) {
|
2020-10-15 02:26:51 +08:00
|
|
|
sp = alloc_tdp_mmu_page(vcpu, iter.gfn, iter.level);
|
|
|
|
list_add(&sp->link, &vcpu->kvm->arch.tdp_mmu_pages);
|
|
|
|
child_pt = sp->spt;
|
2020-10-15 02:26:50 +08:00
|
|
|
clear_page(child_pt);
|
|
|
|
new_spte = make_nonleaf_spte(child_pt,
|
|
|
|
!shadow_accessed_mask);
|
|
|
|
|
|
|
|
trace_kvm_mmu_get_page(sp, true);
|
2020-10-15 02:27:00 +08:00
|
|
|
if (huge_page_disallowed && req_level >= iter.level)
|
|
|
|
account_huge_nx_page(vcpu->kvm, sp);
|
|
|
|
|
2020-10-15 02:26:50 +08:00
|
|
|
tdp_mmu_set_spte(vcpu->kvm, &iter, new_spte);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
if (WARN_ON(iter.level != level))
|
|
|
|
return RET_PF_RETRY;
|
|
|
|
|
|
|
|
ret = tdp_mmu_map_handle_target_level(vcpu, write, map_writable, &iter,
|
|
|
|
pfn, prefault);
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
}
|
2020-10-15 02:26:52 +08:00
|
|
|
|
|
|
|
static int kvm_tdp_mmu_handle_hva_range(struct kvm *kvm, unsigned long start,
|
|
|
|
unsigned long end, unsigned long data,
|
|
|
|
int (*handler)(struct kvm *kvm, struct kvm_memory_slot *slot,
|
|
|
|
struct kvm_mmu_page *root, gfn_t start,
|
|
|
|
gfn_t end, unsigned long data))
|
|
|
|
{
|
|
|
|
struct kvm_memslots *slots;
|
|
|
|
struct kvm_memory_slot *memslot;
|
|
|
|
struct kvm_mmu_page *root;
|
|
|
|
int ret = 0;
|
|
|
|
int as_id;
|
|
|
|
|
|
|
|
for_each_tdp_mmu_root(kvm, root) {
|
|
|
|
/*
|
|
|
|
* Take a reference on the root so that it cannot be freed if
|
|
|
|
* this thread releases the MMU lock and yields in this loop.
|
|
|
|
*/
|
|
|
|
kvm_mmu_get_root(kvm, root);
|
|
|
|
|
|
|
|
as_id = kvm_mmu_page_as_id(root);
|
|
|
|
slots = __kvm_memslots(kvm, as_id);
|
|
|
|
kvm_for_each_memslot(memslot, slots) {
|
|
|
|
unsigned long hva_start, hva_end;
|
|
|
|
gfn_t gfn_start, gfn_end;
|
|
|
|
|
|
|
|
hva_start = max(start, memslot->userspace_addr);
|
|
|
|
hva_end = min(end, memslot->userspace_addr +
|
|
|
|
(memslot->npages << PAGE_SHIFT));
|
|
|
|
if (hva_start >= hva_end)
|
|
|
|
continue;
|
|
|
|
/*
|
|
|
|
* {gfn(page) | page intersects with [hva_start, hva_end)} =
|
|
|
|
* {gfn_start, gfn_start+1, ..., gfn_end-1}.
|
|
|
|
*/
|
|
|
|
gfn_start = hva_to_gfn_memslot(hva_start, memslot);
|
|
|
|
gfn_end = hva_to_gfn_memslot(hva_end + PAGE_SIZE - 1, memslot);
|
|
|
|
|
|
|
|
ret |= handler(kvm, memslot, root, gfn_start,
|
|
|
|
gfn_end, data);
|
|
|
|
}
|
|
|
|
|
|
|
|
kvm_mmu_put_root(kvm, root);
|
|
|
|
}
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
|
|
|
static int zap_gfn_range_hva_wrapper(struct kvm *kvm,
|
|
|
|
struct kvm_memory_slot *slot,
|
|
|
|
struct kvm_mmu_page *root, gfn_t start,
|
|
|
|
gfn_t end, unsigned long unused)
|
|
|
|
{
|
|
|
|
return zap_gfn_range(kvm, root, start, end, false);
|
|
|
|
}
|
|
|
|
|
|
|
|
int kvm_tdp_mmu_zap_hva_range(struct kvm *kvm, unsigned long start,
|
|
|
|
unsigned long end)
|
|
|
|
{
|
|
|
|
return kvm_tdp_mmu_handle_hva_range(kvm, start, end, 0,
|
|
|
|
zap_gfn_range_hva_wrapper);
|
|
|
|
}
|
2020-10-15 02:26:53 +08:00
|
|
|
|
|
|
|
/*
|
|
|
|
* Mark the SPTEs range of GFNs [start, end) unaccessed and return non-zero
|
|
|
|
* if any of the GFNs in the range have been accessed.
|
|
|
|
*/
|
|
|
|
static int age_gfn_range(struct kvm *kvm, struct kvm_memory_slot *slot,
|
|
|
|
struct kvm_mmu_page *root, gfn_t start, gfn_t end,
|
|
|
|
unsigned long unused)
|
|
|
|
{
|
|
|
|
struct tdp_iter iter;
|
|
|
|
int young = 0;
|
|
|
|
u64 new_spte = 0;
|
|
|
|
|
|
|
|
tdp_root_for_each_leaf_pte(iter, root, start, end) {
|
|
|
|
/*
|
|
|
|
* If we have a non-accessed entry we don't need to change the
|
|
|
|
* pte.
|
|
|
|
*/
|
|
|
|
if (!is_accessed_spte(iter.old_spte))
|
|
|
|
continue;
|
|
|
|
|
|
|
|
new_spte = iter.old_spte;
|
|
|
|
|
|
|
|
if (spte_ad_enabled(new_spte)) {
|
|
|
|
clear_bit((ffs(shadow_accessed_mask) - 1),
|
|
|
|
(unsigned long *)&new_spte);
|
|
|
|
} else {
|
|
|
|
/*
|
|
|
|
* Capture the dirty status of the page, so that it doesn't get
|
|
|
|
* lost when the SPTE is marked for access tracking.
|
|
|
|
*/
|
|
|
|
if (is_writable_pte(new_spte))
|
|
|
|
kvm_set_pfn_dirty(spte_to_pfn(new_spte));
|
|
|
|
|
|
|
|
new_spte = mark_spte_for_access_track(new_spte);
|
|
|
|
}
|
2020-10-15 02:26:55 +08:00
|
|
|
new_spte &= ~shadow_dirty_mask;
|
2020-10-15 02:26:53 +08:00
|
|
|
|
|
|
|
tdp_mmu_set_spte_no_acc_track(kvm, &iter, new_spte);
|
|
|
|
young = 1;
|
|
|
|
}
|
|
|
|
|
|
|
|
return young;
|
|
|
|
}
|
|
|
|
|
|
|
|
int kvm_tdp_mmu_age_hva_range(struct kvm *kvm, unsigned long start,
|
|
|
|
unsigned long end)
|
|
|
|
{
|
|
|
|
return kvm_tdp_mmu_handle_hva_range(kvm, start, end, 0,
|
|
|
|
age_gfn_range);
|
|
|
|
}
|
|
|
|
|
|
|
|
static int test_age_gfn(struct kvm *kvm, struct kvm_memory_slot *slot,
|
|
|
|
struct kvm_mmu_page *root, gfn_t gfn, gfn_t unused,
|
|
|
|
unsigned long unused2)
|
|
|
|
{
|
|
|
|
struct tdp_iter iter;
|
|
|
|
|
|
|
|
tdp_root_for_each_leaf_pte(iter, root, gfn, gfn + 1)
|
|
|
|
if (is_accessed_spte(iter.old_spte))
|
|
|
|
return 1;
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
int kvm_tdp_mmu_test_age_hva(struct kvm *kvm, unsigned long hva)
|
|
|
|
{
|
|
|
|
return kvm_tdp_mmu_handle_hva_range(kvm, hva, hva + 1, 0,
|
|
|
|
test_age_gfn);
|
|
|
|
}
|
2020-10-15 02:26:54 +08:00
|
|
|
|
|
|
|
/*
|
|
|
|
* Handle the changed_pte MMU notifier for the TDP MMU.
|
|
|
|
* data is a pointer to the new pte_t mapping the HVA specified by the MMU
|
|
|
|
* notifier.
|
|
|
|
* Returns non-zero if a flush is needed before releasing the MMU lock.
|
|
|
|
*/
|
|
|
|
static int set_tdp_spte(struct kvm *kvm, struct kvm_memory_slot *slot,
|
|
|
|
struct kvm_mmu_page *root, gfn_t gfn, gfn_t unused,
|
|
|
|
unsigned long data)
|
|
|
|
{
|
|
|
|
struct tdp_iter iter;
|
|
|
|
pte_t *ptep = (pte_t *)data;
|
|
|
|
kvm_pfn_t new_pfn;
|
|
|
|
u64 new_spte;
|
|
|
|
int need_flush = 0;
|
|
|
|
|
|
|
|
WARN_ON(pte_huge(*ptep));
|
|
|
|
|
|
|
|
new_pfn = pte_pfn(*ptep);
|
|
|
|
|
|
|
|
tdp_root_for_each_pte(iter, root, gfn, gfn + 1) {
|
|
|
|
if (iter.level != PG_LEVEL_4K)
|
|
|
|
continue;
|
|
|
|
|
|
|
|
if (!is_shadow_present_pte(iter.old_spte))
|
|
|
|
break;
|
|
|
|
|
|
|
|
tdp_mmu_set_spte(kvm, &iter, 0);
|
|
|
|
|
|
|
|
kvm_flush_remote_tlbs_with_address(kvm, iter.gfn, 1);
|
|
|
|
|
|
|
|
if (!pte_write(*ptep)) {
|
|
|
|
new_spte = kvm_mmu_changed_pte_notifier_make_spte(
|
|
|
|
iter.old_spte, new_pfn);
|
|
|
|
|
|
|
|
tdp_mmu_set_spte(kvm, &iter, new_spte);
|
|
|
|
}
|
|
|
|
|
|
|
|
need_flush = 1;
|
|
|
|
}
|
|
|
|
|
|
|
|
if (need_flush)
|
|
|
|
kvm_flush_remote_tlbs_with_address(kvm, gfn, 1);
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
int kvm_tdp_mmu_set_spte_hva(struct kvm *kvm, unsigned long address,
|
|
|
|
pte_t *host_ptep)
|
|
|
|
{
|
|
|
|
return kvm_tdp_mmu_handle_hva_range(kvm, address, address + 1,
|
|
|
|
(unsigned long)host_ptep,
|
|
|
|
set_tdp_spte);
|
|
|
|
}
|
|
|
|
|
2020-10-15 02:26:55 +08:00
|
|
|
/*
|
|
|
|
* Remove write access from all the SPTEs mapping GFNs [start, end). If
|
|
|
|
* skip_4k is set, SPTEs that map 4k pages, will not be write-protected.
|
|
|
|
* Returns true if an SPTE has been changed and the TLBs need to be flushed.
|
|
|
|
*/
|
|
|
|
static bool wrprot_gfn_range(struct kvm *kvm, struct kvm_mmu_page *root,
|
|
|
|
gfn_t start, gfn_t end, int min_level)
|
|
|
|
{
|
|
|
|
struct tdp_iter iter;
|
|
|
|
u64 new_spte;
|
|
|
|
bool spte_set = false;
|
|
|
|
|
|
|
|
BUG_ON(min_level > KVM_MAX_HUGEPAGE_LEVEL);
|
|
|
|
|
|
|
|
for_each_tdp_pte_min_level(iter, root->spt, root->role.level,
|
|
|
|
min_level, start, end) {
|
|
|
|
if (!is_shadow_present_pte(iter.old_spte) ||
|
|
|
|
!is_last_spte(iter.old_spte, iter.level))
|
|
|
|
continue;
|
|
|
|
|
|
|
|
new_spte = iter.old_spte & ~PT_WRITABLE_MASK;
|
|
|
|
|
|
|
|
tdp_mmu_set_spte_no_dirty_log(kvm, &iter, new_spte);
|
|
|
|
spte_set = true;
|
|
|
|
|
|
|
|
tdp_mmu_iter_cond_resched(kvm, &iter);
|
|
|
|
}
|
|
|
|
return spte_set;
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Remove write access from all the SPTEs mapping GFNs in the memslot. Will
|
|
|
|
* only affect leaf SPTEs down to min_level.
|
|
|
|
* Returns true if an SPTE has been changed and the TLBs need to be flushed.
|
|
|
|
*/
|
|
|
|
bool kvm_tdp_mmu_wrprot_slot(struct kvm *kvm, struct kvm_memory_slot *slot,
|
|
|
|
int min_level)
|
|
|
|
{
|
|
|
|
struct kvm_mmu_page *root;
|
|
|
|
int root_as_id;
|
|
|
|
bool spte_set = false;
|
|
|
|
|
|
|
|
for_each_tdp_mmu_root(kvm, root) {
|
|
|
|
root_as_id = kvm_mmu_page_as_id(root);
|
|
|
|
if (root_as_id != slot->as_id)
|
|
|
|
continue;
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Take a reference on the root so that it cannot be freed if
|
|
|
|
* this thread releases the MMU lock and yields in this loop.
|
|
|
|
*/
|
|
|
|
kvm_mmu_get_root(kvm, root);
|
|
|
|
|
|
|
|
spte_set |= wrprot_gfn_range(kvm, root, slot->base_gfn,
|
|
|
|
slot->base_gfn + slot->npages, min_level);
|
|
|
|
|
|
|
|
kvm_mmu_put_root(kvm, root);
|
|
|
|
}
|
|
|
|
|
|
|
|
return spte_set;
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Clear the dirty status of all the SPTEs mapping GFNs in the memslot. If
|
|
|
|
* AD bits are enabled, this will involve clearing the dirty bit on each SPTE.
|
|
|
|
* If AD bits are not enabled, this will require clearing the writable bit on
|
|
|
|
* each SPTE. Returns true if an SPTE has been changed and the TLBs need to
|
|
|
|
* be flushed.
|
|
|
|
*/
|
|
|
|
static bool clear_dirty_gfn_range(struct kvm *kvm, struct kvm_mmu_page *root,
|
|
|
|
gfn_t start, gfn_t end)
|
|
|
|
{
|
|
|
|
struct tdp_iter iter;
|
|
|
|
u64 new_spte;
|
|
|
|
bool spte_set = false;
|
|
|
|
|
|
|
|
tdp_root_for_each_leaf_pte(iter, root, start, end) {
|
|
|
|
if (spte_ad_need_write_protect(iter.old_spte)) {
|
|
|
|
if (is_writable_pte(iter.old_spte))
|
|
|
|
new_spte = iter.old_spte & ~PT_WRITABLE_MASK;
|
|
|
|
else
|
|
|
|
continue;
|
|
|
|
} else {
|
|
|
|
if (iter.old_spte & shadow_dirty_mask)
|
|
|
|
new_spte = iter.old_spte & ~shadow_dirty_mask;
|
|
|
|
else
|
|
|
|
continue;
|
|
|
|
}
|
|
|
|
|
|
|
|
tdp_mmu_set_spte_no_dirty_log(kvm, &iter, new_spte);
|
|
|
|
spte_set = true;
|
|
|
|
|
|
|
|
tdp_mmu_iter_cond_resched(kvm, &iter);
|
|
|
|
}
|
|
|
|
return spte_set;
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Clear the dirty status of all the SPTEs mapping GFNs in the memslot. If
|
|
|
|
* AD bits are enabled, this will involve clearing the dirty bit on each SPTE.
|
|
|
|
* If AD bits are not enabled, this will require clearing the writable bit on
|
|
|
|
* each SPTE. Returns true if an SPTE has been changed and the TLBs need to
|
|
|
|
* be flushed.
|
|
|
|
*/
|
|
|
|
bool kvm_tdp_mmu_clear_dirty_slot(struct kvm *kvm, struct kvm_memory_slot *slot)
|
|
|
|
{
|
|
|
|
struct kvm_mmu_page *root;
|
|
|
|
int root_as_id;
|
|
|
|
bool spte_set = false;
|
|
|
|
|
|
|
|
for_each_tdp_mmu_root(kvm, root) {
|
|
|
|
root_as_id = kvm_mmu_page_as_id(root);
|
|
|
|
if (root_as_id != slot->as_id)
|
|
|
|
continue;
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Take a reference on the root so that it cannot be freed if
|
|
|
|
* this thread releases the MMU lock and yields in this loop.
|
|
|
|
*/
|
|
|
|
kvm_mmu_get_root(kvm, root);
|
|
|
|
|
|
|
|
spte_set |= clear_dirty_gfn_range(kvm, root, slot->base_gfn,
|
|
|
|
slot->base_gfn + slot->npages);
|
|
|
|
|
|
|
|
kvm_mmu_put_root(kvm, root);
|
|
|
|
}
|
|
|
|
|
|
|
|
return spte_set;
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Clears the dirty status of all the 4k SPTEs mapping GFNs for which a bit is
|
|
|
|
* set in mask, starting at gfn. The given memslot is expected to contain all
|
|
|
|
* the GFNs represented by set bits in the mask. If AD bits are enabled,
|
|
|
|
* clearing the dirty status will involve clearing the dirty bit on each SPTE
|
|
|
|
* or, if AD bits are not enabled, clearing the writable bit on each SPTE.
|
|
|
|
*/
|
|
|
|
static void clear_dirty_pt_masked(struct kvm *kvm, struct kvm_mmu_page *root,
|
|
|
|
gfn_t gfn, unsigned long mask, bool wrprot)
|
|
|
|
{
|
|
|
|
struct tdp_iter iter;
|
|
|
|
u64 new_spte;
|
|
|
|
|
|
|
|
tdp_root_for_each_leaf_pte(iter, root, gfn + __ffs(mask),
|
|
|
|
gfn + BITS_PER_LONG) {
|
|
|
|
if (!mask)
|
|
|
|
break;
|
|
|
|
|
|
|
|
if (iter.level > PG_LEVEL_4K ||
|
|
|
|
!(mask & (1UL << (iter.gfn - gfn))))
|
|
|
|
continue;
|
|
|
|
|
|
|
|
if (wrprot || spte_ad_need_write_protect(iter.old_spte)) {
|
|
|
|
if (is_writable_pte(iter.old_spte))
|
|
|
|
new_spte = iter.old_spte & ~PT_WRITABLE_MASK;
|
|
|
|
else
|
|
|
|
continue;
|
|
|
|
} else {
|
|
|
|
if (iter.old_spte & shadow_dirty_mask)
|
|
|
|
new_spte = iter.old_spte & ~shadow_dirty_mask;
|
|
|
|
else
|
|
|
|
continue;
|
|
|
|
}
|
|
|
|
|
|
|
|
tdp_mmu_set_spte_no_dirty_log(kvm, &iter, new_spte);
|
|
|
|
|
|
|
|
mask &= ~(1UL << (iter.gfn - gfn));
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Clears the dirty status of all the 4k SPTEs mapping GFNs for which a bit is
|
|
|
|
* set in mask, starting at gfn. The given memslot is expected to contain all
|
|
|
|
* the GFNs represented by set bits in the mask. If AD bits are enabled,
|
|
|
|
* clearing the dirty status will involve clearing the dirty bit on each SPTE
|
|
|
|
* or, if AD bits are not enabled, clearing the writable bit on each SPTE.
|
|
|
|
*/
|
|
|
|
void kvm_tdp_mmu_clear_dirty_pt_masked(struct kvm *kvm,
|
|
|
|
struct kvm_memory_slot *slot,
|
|
|
|
gfn_t gfn, unsigned long mask,
|
|
|
|
bool wrprot)
|
|
|
|
{
|
|
|
|
struct kvm_mmu_page *root;
|
|
|
|
int root_as_id;
|
|
|
|
|
|
|
|
lockdep_assert_held(&kvm->mmu_lock);
|
|
|
|
for_each_tdp_mmu_root(kvm, root) {
|
|
|
|
root_as_id = kvm_mmu_page_as_id(root);
|
|
|
|
if (root_as_id != slot->as_id)
|
|
|
|
continue;
|
|
|
|
|
|
|
|
clear_dirty_pt_masked(kvm, root, gfn, mask, wrprot);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Set the dirty status of all the SPTEs mapping GFNs in the memslot. This is
|
|
|
|
* only used for PML, and so will involve setting the dirty bit on each SPTE.
|
|
|
|
* Returns true if an SPTE has been changed and the TLBs need to be flushed.
|
|
|
|
*/
|
|
|
|
static bool set_dirty_gfn_range(struct kvm *kvm, struct kvm_mmu_page *root,
|
|
|
|
gfn_t start, gfn_t end)
|
|
|
|
{
|
|
|
|
struct tdp_iter iter;
|
|
|
|
u64 new_spte;
|
|
|
|
bool spte_set = false;
|
|
|
|
|
|
|
|
tdp_root_for_each_pte(iter, root, start, end) {
|
|
|
|
if (!is_shadow_present_pte(iter.old_spte))
|
|
|
|
continue;
|
|
|
|
|
|
|
|
new_spte = iter.old_spte | shadow_dirty_mask;
|
|
|
|
|
|
|
|
tdp_mmu_set_spte(kvm, &iter, new_spte);
|
|
|
|
spte_set = true;
|
|
|
|
|
|
|
|
tdp_mmu_iter_cond_resched(kvm, &iter);
|
|
|
|
}
|
|
|
|
|
|
|
|
return spte_set;
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Set the dirty status of all the SPTEs mapping GFNs in the memslot. This is
|
|
|
|
* only used for PML, and so will involve setting the dirty bit on each SPTE.
|
|
|
|
* Returns true if an SPTE has been changed and the TLBs need to be flushed.
|
|
|
|
*/
|
|
|
|
bool kvm_tdp_mmu_slot_set_dirty(struct kvm *kvm, struct kvm_memory_slot *slot)
|
|
|
|
{
|
|
|
|
struct kvm_mmu_page *root;
|
|
|
|
int root_as_id;
|
|
|
|
bool spte_set = false;
|
|
|
|
|
|
|
|
for_each_tdp_mmu_root(kvm, root) {
|
|
|
|
root_as_id = kvm_mmu_page_as_id(root);
|
|
|
|
if (root_as_id != slot->as_id)
|
|
|
|
continue;
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Take a reference on the root so that it cannot be freed if
|
|
|
|
* this thread releases the MMU lock and yields in this loop.
|
|
|
|
*/
|
|
|
|
kvm_mmu_get_root(kvm, root);
|
|
|
|
|
|
|
|
spte_set |= set_dirty_gfn_range(kvm, root, slot->base_gfn,
|
|
|
|
slot->base_gfn + slot->npages);
|
|
|
|
|
|
|
|
kvm_mmu_put_root(kvm, root);
|
|
|
|
}
|
|
|
|
return spte_set;
|
|
|
|
}
|
|
|
|
|
2020-10-15 02:26:56 +08:00
|
|
|
/*
|
|
|
|
* Clear non-leaf entries (and free associated page tables) which could
|
|
|
|
* be replaced by large mappings, for GFNs within the slot.
|
|
|
|
*/
|
|
|
|
static void zap_collapsible_spte_range(struct kvm *kvm,
|
|
|
|
struct kvm_mmu_page *root,
|
|
|
|
gfn_t start, gfn_t end)
|
|
|
|
{
|
|
|
|
struct tdp_iter iter;
|
|
|
|
kvm_pfn_t pfn;
|
|
|
|
bool spte_set = false;
|
|
|
|
|
|
|
|
tdp_root_for_each_pte(iter, root, start, end) {
|
|
|
|
if (!is_shadow_present_pte(iter.old_spte) ||
|
|
|
|
is_last_spte(iter.old_spte, iter.level))
|
|
|
|
continue;
|
|
|
|
|
|
|
|
pfn = spte_to_pfn(iter.old_spte);
|
|
|
|
if (kvm_is_reserved_pfn(pfn) ||
|
|
|
|
!PageTransCompoundMap(pfn_to_page(pfn)))
|
|
|
|
continue;
|
|
|
|
|
|
|
|
tdp_mmu_set_spte(kvm, &iter, 0);
|
|
|
|
|
|
|
|
spte_set = tdp_mmu_iter_flush_cond_resched(kvm, &iter);
|
|
|
|
}
|
|
|
|
|
|
|
|
if (spte_set)
|
|
|
|
kvm_flush_remote_tlbs(kvm);
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Clear non-leaf entries (and free associated page tables) which could
|
|
|
|
* be replaced by large mappings, for GFNs within the slot.
|
|
|
|
*/
|
|
|
|
void kvm_tdp_mmu_zap_collapsible_sptes(struct kvm *kvm,
|
|
|
|
const struct kvm_memory_slot *slot)
|
|
|
|
{
|
|
|
|
struct kvm_mmu_page *root;
|
|
|
|
int root_as_id;
|
|
|
|
|
|
|
|
for_each_tdp_mmu_root(kvm, root) {
|
|
|
|
root_as_id = kvm_mmu_page_as_id(root);
|
|
|
|
if (root_as_id != slot->as_id)
|
|
|
|
continue;
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Take a reference on the root so that it cannot be freed if
|
|
|
|
* this thread releases the MMU lock and yields in this loop.
|
|
|
|
*/
|
|
|
|
kvm_mmu_get_root(kvm, root);
|
|
|
|
|
|
|
|
zap_collapsible_spte_range(kvm, root, slot->base_gfn,
|
|
|
|
slot->base_gfn + slot->npages);
|
|
|
|
|
|
|
|
kvm_mmu_put_root(kvm, root);
|
|
|
|
}
|
|
|
|
}
|
2020-10-15 02:26:57 +08:00
|
|
|
|
|
|
|
/*
|
|
|
|
* Removes write access on the last level SPTE mapping this GFN and unsets the
|
|
|
|
* SPTE_MMU_WRITABLE bit to ensure future writes continue to be intercepted.
|
|
|
|
* Returns true if an SPTE was set and a TLB flush is needed.
|
|
|
|
*/
|
|
|
|
static bool write_protect_gfn(struct kvm *kvm, struct kvm_mmu_page *root,
|
|
|
|
gfn_t gfn)
|
|
|
|
{
|
|
|
|
struct tdp_iter iter;
|
|
|
|
u64 new_spte;
|
|
|
|
bool spte_set = false;
|
|
|
|
|
|
|
|
tdp_root_for_each_leaf_pte(iter, root, gfn, gfn + 1) {
|
|
|
|
if (!is_writable_pte(iter.old_spte))
|
|
|
|
break;
|
|
|
|
|
|
|
|
new_spte = iter.old_spte &
|
|
|
|
~(PT_WRITABLE_MASK | SPTE_MMU_WRITEABLE);
|
|
|
|
|
|
|
|
tdp_mmu_set_spte(kvm, &iter, new_spte);
|
|
|
|
spte_set = true;
|
|
|
|
}
|
|
|
|
|
|
|
|
return spte_set;
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Removes write access on the last level SPTE mapping this GFN and unsets the
|
|
|
|
* SPTE_MMU_WRITABLE bit to ensure future writes continue to be intercepted.
|
|
|
|
* Returns true if an SPTE was set and a TLB flush is needed.
|
|
|
|
*/
|
|
|
|
bool kvm_tdp_mmu_write_protect_gfn(struct kvm *kvm,
|
|
|
|
struct kvm_memory_slot *slot, gfn_t gfn)
|
|
|
|
{
|
|
|
|
struct kvm_mmu_page *root;
|
|
|
|
int root_as_id;
|
|
|
|
bool spte_set = false;
|
|
|
|
|
|
|
|
lockdep_assert_held(&kvm->mmu_lock);
|
|
|
|
for_each_tdp_mmu_root(kvm, root) {
|
|
|
|
root_as_id = kvm_mmu_page_as_id(root);
|
|
|
|
if (root_as_id != slot->as_id)
|
|
|
|
continue;
|
|
|
|
|
|
|
|
spte_set |= write_protect_gfn(kvm, root, gfn);
|
|
|
|
}
|
|
|
|
return spte_set;
|
|
|
|
}
|
|
|
|
|
2020-10-15 02:26:58 +08:00
|
|
|
/*
|
|
|
|
* Return the level of the lowest level SPTE added to sptes.
|
|
|
|
* That SPTE may be non-present.
|
|
|
|
*/
|
|
|
|
int kvm_tdp_mmu_get_walk(struct kvm_vcpu *vcpu, u64 addr, u64 *sptes)
|
|
|
|
{
|
|
|
|
struct tdp_iter iter;
|
|
|
|
struct kvm_mmu *mmu = vcpu->arch.mmu;
|
|
|
|
gfn_t gfn = addr >> PAGE_SHIFT;
|
2020-12-18 08:31:36 +08:00
|
|
|
int leaf = -1;
|
2020-10-15 02:26:58 +08:00
|
|
|
|
|
|
|
tdp_mmu_for_each_pte(iter, mmu, gfn, gfn + 1) {
|
|
|
|
leaf = iter.level;
|
|
|
|
sptes[leaf - 1] = iter.old_spte;
|
|
|
|
}
|
|
|
|
|
|
|
|
return leaf;
|
|
|
|
}
|