KVM: MMU: use page array in unsync walk
Instead of invoking the handler directly collect pages into an array so the caller can work with it. Simplifies TLB flush collapsing. Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
This commit is contained in:
Marcelo Tosatti
Avi Kivity
Родитель
fbce554e94
Коммит
60c8aec6e2
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@ -200,7 +200,7 @@ struct kvm_mmu_page {
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int multimapped; /* More than one parent_pte? */
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int root_count; /* Currently serving as active root */
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bool unsync;
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bool unsync_children;
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unsigned int unsync_children;
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union {
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u64 *parent_pte; /* !multimapped */
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struct hlist_head parent_ptes; /* multimapped, kvm_pte_chain */
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@ -908,8 +908,9 @@ static void kvm_mmu_update_unsync_bitmap(u64 *spte)
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struct kvm_mmu_page *sp = page_header(__pa(spte));
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index = spte - sp->spt;
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__set_bit(index, sp->unsync_child_bitmap);
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sp->unsync_children = 1;
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if (!__test_and_set_bit(index, sp->unsync_child_bitmap))
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sp->unsync_children++;
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WARN_ON(!sp->unsync_children);
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}
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static void kvm_mmu_update_parents_unsync(struct kvm_mmu_page *sp)
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@ -936,7 +937,6 @@ static void kvm_mmu_update_parents_unsync(struct kvm_mmu_page *sp)
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static int unsync_walk_fn(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
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{
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sp->unsync_children = 1;
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kvm_mmu_update_parents_unsync(sp);
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return 1;
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}
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@ -967,18 +967,41 @@ static void nonpaging_invlpg(struct kvm_vcpu *vcpu, gva_t gva)
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{
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}
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#define KVM_PAGE_ARRAY_NR 16
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struct kvm_mmu_pages {
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struct mmu_page_and_offset {
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struct kvm_mmu_page *sp;
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unsigned int idx;
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} page[KVM_PAGE_ARRAY_NR];
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unsigned int nr;
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};
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#define for_each_unsync_children(bitmap, idx) \
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for (idx = find_first_bit(bitmap, 512); \
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idx < 512; \
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idx = find_next_bit(bitmap, 512, idx+1))
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static int mmu_unsync_walk(struct kvm_mmu_page *sp,
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struct kvm_unsync_walk *walker)
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int mmu_pages_add(struct kvm_mmu_pages *pvec, struct kvm_mmu_page *sp,
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int idx)
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{
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int i, ret;
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int i;
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if (!sp->unsync_children)
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return 0;
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if (sp->unsync)
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for (i=0; i < pvec->nr; i++)
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if (pvec->page[i].sp == sp)
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return 0;
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pvec->page[pvec->nr].sp = sp;
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pvec->page[pvec->nr].idx = idx;
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pvec->nr++;
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return (pvec->nr == KVM_PAGE_ARRAY_NR);
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}
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static int __mmu_unsync_walk(struct kvm_mmu_page *sp,
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struct kvm_mmu_pages *pvec)
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{
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int i, ret, nr_unsync_leaf = 0;
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for_each_unsync_children(sp->unsync_child_bitmap, i) {
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u64 ent = sp->spt[i];
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@ -988,17 +1011,22 @@ static int mmu_unsync_walk(struct kvm_mmu_page *sp,
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child = page_header(ent & PT64_BASE_ADDR_MASK);
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if (child->unsync_children) {
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ret = mmu_unsync_walk(child, walker);
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if (ret)
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if (mmu_pages_add(pvec, child, i))
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return -ENOSPC;
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ret = __mmu_unsync_walk(child, pvec);
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if (!ret)
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__clear_bit(i, sp->unsync_child_bitmap);
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else if (ret > 0)
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nr_unsync_leaf += ret;
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else
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return ret;
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__clear_bit(i, sp->unsync_child_bitmap);
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}
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if (child->unsync) {
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ret = walker->entry(child, walker);
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__clear_bit(i, sp->unsync_child_bitmap);
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if (ret)
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return ret;
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nr_unsync_leaf++;
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if (mmu_pages_add(pvec, child, i))
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return -ENOSPC;
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}
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}
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}
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@ -1006,7 +1034,17 @@ static int mmu_unsync_walk(struct kvm_mmu_page *sp,
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if (find_first_bit(sp->unsync_child_bitmap, 512) == 512)
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sp->unsync_children = 0;
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return 0;
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return nr_unsync_leaf;
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}
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static int mmu_unsync_walk(struct kvm_mmu_page *sp,
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struct kvm_mmu_pages *pvec)
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{
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if (!sp->unsync_children)
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return 0;
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mmu_pages_add(pvec, sp, 0);
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return __mmu_unsync_walk(sp, pvec);
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}
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static struct kvm_mmu_page *kvm_mmu_lookup_page(struct kvm *kvm, gfn_t gfn)
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@ -1056,30 +1094,81 @@ static int kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
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return 0;
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}
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struct sync_walker {
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struct kvm_vcpu *vcpu;
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struct kvm_unsync_walk walker;
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struct mmu_page_path {
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struct kvm_mmu_page *parent[PT64_ROOT_LEVEL-1];
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unsigned int idx[PT64_ROOT_LEVEL-1];
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};
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static int mmu_sync_fn(struct kvm_mmu_page *sp, struct kvm_unsync_walk *walk)
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{
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struct sync_walker *sync_walk = container_of(walk, struct sync_walker,
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walker);
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struct kvm_vcpu *vcpu = sync_walk->vcpu;
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#define for_each_sp(pvec, sp, parents, i) \
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for (i = mmu_pages_next(&pvec, &parents, -1), \
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sp = pvec.page[i].sp; \
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i < pvec.nr && ({ sp = pvec.page[i].sp; 1;}); \
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i = mmu_pages_next(&pvec, &parents, i))
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kvm_sync_page(vcpu, sp);
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return (need_resched() || spin_needbreak(&vcpu->kvm->mmu_lock));
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int mmu_pages_next(struct kvm_mmu_pages *pvec, struct mmu_page_path *parents,
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int i)
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{
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int n;
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for (n = i+1; n < pvec->nr; n++) {
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struct kvm_mmu_page *sp = pvec->page[n].sp;
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if (sp->role.level == PT_PAGE_TABLE_LEVEL) {
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parents->idx[0] = pvec->page[n].idx;
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return n;
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}
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parents->parent[sp->role.level-2] = sp;
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parents->idx[sp->role.level-1] = pvec->page[n].idx;
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}
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return n;
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}
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static void mmu_sync_children(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
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void mmu_pages_clear_parents(struct mmu_page_path *parents)
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{
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struct sync_walker walker = {
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.walker = { .entry = mmu_sync_fn, },
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.vcpu = vcpu,
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};
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struct kvm_mmu_page *sp;
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unsigned int level = 0;
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while (mmu_unsync_walk(sp, &walker.walker))
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do {
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unsigned int idx = parents->idx[level];
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sp = parents->parent[level];
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if (!sp)
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return;
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--sp->unsync_children;
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WARN_ON((int)sp->unsync_children < 0);
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__clear_bit(idx, sp->unsync_child_bitmap);
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level++;
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} while (level < PT64_ROOT_LEVEL-1 && !sp->unsync_children);
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}
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static void kvm_mmu_pages_init(struct kvm_mmu_page *parent,
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struct mmu_page_path *parents,
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struct kvm_mmu_pages *pvec)
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{
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parents->parent[parent->role.level-1] = NULL;
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pvec->nr = 0;
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}
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static void mmu_sync_children(struct kvm_vcpu *vcpu,
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struct kvm_mmu_page *parent)
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{
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int i;
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struct kvm_mmu_page *sp;
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struct mmu_page_path parents;
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struct kvm_mmu_pages pages;
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kvm_mmu_pages_init(parent, &parents, &pages);
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while (mmu_unsync_walk(parent, &pages)) {
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for_each_sp(pages, sp, parents, i) {
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kvm_sync_page(vcpu, sp);
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mmu_pages_clear_parents(&parents);
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}
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cond_resched_lock(&vcpu->kvm->mmu_lock);
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kvm_mmu_pages_init(parent, &parents, &pages);
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}
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}
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static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
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@ -1245,33 +1334,29 @@ static void kvm_mmu_unlink_parents(struct kvm *kvm, struct kvm_mmu_page *sp)
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}
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}
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struct zap_walker {
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struct kvm_unsync_walk walker;
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struct kvm *kvm;
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int zapped;
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};
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static int mmu_zap_fn(struct kvm_mmu_page *sp, struct kvm_unsync_walk *walk)
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static int mmu_zap_unsync_children(struct kvm *kvm,
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struct kvm_mmu_page *parent)
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{
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struct zap_walker *zap_walk = container_of(walk, struct zap_walker,
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walker);
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kvm_mmu_zap_page(zap_walk->kvm, sp);
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zap_walk->zapped = 1;
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return 0;
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}
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int i, zapped = 0;
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struct mmu_page_path parents;
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struct kvm_mmu_pages pages;
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static int mmu_zap_unsync_children(struct kvm *kvm, struct kvm_mmu_page *sp)
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{
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struct zap_walker walker = {
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.walker = { .entry = mmu_zap_fn, },
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.kvm = kvm,
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.zapped = 0,
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};
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if (sp->role.level == PT_PAGE_TABLE_LEVEL)
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if (parent->role.level == PT_PAGE_TABLE_LEVEL)
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return 0;
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mmu_unsync_walk(sp, &walker.walker);
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return walker.zapped;
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kvm_mmu_pages_init(parent, &parents, &pages);
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while (mmu_unsync_walk(parent, &pages)) {
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struct kvm_mmu_page *sp;
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for_each_sp(pages, sp, parents, i) {
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kvm_mmu_zap_page(kvm, sp);
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mmu_pages_clear_parents(&parents);
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}
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zapped += pages.nr;
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kvm_mmu_pages_init(parent, &parents, &pages);
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}
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return zapped;
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}
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static int kvm_mmu_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp)
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