1 // SPDX-License-Identifier: GPL-2.0
8  * Recalculates the pointer to the SPTE for the current GFN and level and
13 	iter->sptep = iter->pt_path[iter->level - 1] +  in tdp_iter_refresh_sptep()
14 		SPTE_INDEX(iter->gfn << PAGE_SHIFT, iter->level);  in tdp_iter_refresh_sptep()
15 	iter->old_spte = kvm_tdp_mmu_read_spte(iter->sptep);  in tdp_iter_refresh_sptep()
18 static gfn_t round_gfn_for_level(gfn_t gfn, int level)  in round_gfn_for_level()  argument
20 	return gfn & -KVM_PAGES_PER_HPAGE(level);  in round_gfn_for_level()
29 	iter->yielded = false;  in tdp_iter_restart()
30 	iter->yielded_gfn = iter->next_last_level_gfn;  in tdp_iter_restart()
31 	iter->level = iter->root_level;  in tdp_iter_restart()
33 	iter->gfn = round_gfn_for_level(iter->next_last_level_gfn, iter->level);  in tdp_iter_restart()
36 	iter->valid = true;  in tdp_iter_restart()
40  * Sets a TDP iterator to walk a pre-order traversal of the paging structure
46 	int root_level = root->role.level;  in tdp_iter_start()
51 	iter->next_last_level_gfn = next_last_level_gfn;  in tdp_iter_start()
52 	iter->root_level = root_level;  in tdp_iter_start()
53 	iter->min_level = min_level;  in tdp_iter_start()
54 	iter->pt_path[iter->root_level - 1] = (tdp_ptep_t)root->spt;  in tdp_iter_start()
55 	iter->as_id = kvm_mmu_page_as_id(root);  in tdp_iter_start()
61  * Given an SPTE and its level, returns a pointer containing the host virtual
65 tdp_ptep_t spte_to_child_pt(u64 spte, int level)  in spte_to_child_pt()  argument
69 	 * last-level entry.  in spte_to_child_pt()
71 	if (!is_shadow_present_pte(spte) || is_last_spte(spte, level))  in spte_to_child_pt()
78  * Steps down one level in the paging structure towards the goal GFN. Returns
79  * true if the iterator was able to step down a level, false otherwise.
85 	if (iter->level == iter->min_level)  in try_step_down()
92 	iter->old_spte = kvm_tdp_mmu_read_spte(iter->sptep);  in try_step_down()
94 	child_pt = spte_to_child_pt(iter->old_spte, iter->level);  in try_step_down()
98 	iter->level--;  in try_step_down()
99 	iter->pt_path[iter->level - 1] = child_pt;  in try_step_down()
100 	iter->gfn = round_gfn_for_level(iter->next_last_level_gfn, iter->level);  in try_step_down()
108  * level. The next entry could point to a page backing guest memory or another
109  * page table, or it could be non-present. Returns true if the iterator was
119 	if (SPTE_INDEX(iter->gfn << PAGE_SHIFT, iter->level) ==  in try_step_side()
120 	    (SPTE_ENT_PER_PAGE - 1))  in try_step_side()
123 	iter->gfn += KVM_PAGES_PER_HPAGE(iter->level);  in try_step_side()
124 	iter->next_last_level_gfn = iter->gfn;  in try_step_side()
125 	iter->sptep++;  in try_step_side()
126 	iter->old_spte = kvm_tdp_mmu_read_spte(iter->sptep);  in try_step_side()
132  * Tries to traverse back up a level in the paging structure so that the walk
138 	if (iter->level == iter->root_level)  in try_step_up()
141 	iter->level++;  in try_step_up()
142 	iter->gfn = round_gfn_for_level(iter->gfn, iter->level);  in try_step_up()
149  * Step to the next SPTE in a pre-order traversal of the paging structure.
151  * GFN, if at a present, non-last-level SPTE, or over to a SPTE mapping a
155  * 1. If the current SPTE is a non-last-level SPTE, step down into the page
166 	if (iter->yielded) {  in tdp_iter_next()
178 	iter->valid = false;  in tdp_iter_next()