1 // SPDX-License-Identifier: GPL-2.0 2 3 #ifndef __KVM_X86_MMU_TDP_ITER_H 4 #define __KVM_X86_MMU_TDP_ITER_H 5 6 #include <linux/kvm_host.h> 7 8 #include "mmu.h" 9 10 typedef u64 __rcu *tdp_ptep_t; 11 12 /* 13 * A TDP iterator performs a pre-order walk over a TDP paging structure. 14 */ 15 struct tdp_iter { 16 /* 17 * The iterator will traverse the paging structure towards the mapping 18 * for this GFN. 19 */ 20 gfn_t next_last_level_gfn; 21 /* 22 * The next_last_level_gfn at the time when the thread last 23 * yielded. Only yielding when the next_last_level_gfn != 24 * yielded_gfn helps ensure forward progress. 25 */ 26 gfn_t yielded_gfn; 27 /* Pointers to the page tables traversed to reach the current SPTE */ 28 tdp_ptep_t pt_path[PT64_ROOT_MAX_LEVEL]; 29 /* A pointer to the current SPTE */ 30 tdp_ptep_t sptep; 31 /* The lowest GFN mapped by the current SPTE */ 32 gfn_t gfn; 33 /* The level of the root page given to the iterator */ 34 int root_level; 35 /* The lowest level the iterator should traverse to */ 36 int min_level; 37 /* The iterator's current level within the paging structure */ 38 int level; 39 /* The address space ID, i.e. SMM vs. regular. */ 40 int as_id; 41 /* A snapshot of the value at sptep */ 42 u64 old_spte; 43 /* 44 * Whether the iterator has a valid state. This will be false if the 45 * iterator walks off the end of the paging structure. 46 */ 47 bool valid; 48 /* 49 * True if KVM dropped mmu_lock and yielded in the middle of a walk, in 50 * which case tdp_iter_next() needs to restart the walk at the root 51 * level instead of advancing to the next entry. 52 */ 53 bool yielded; 54 }; 55 56 /* 57 * Iterates over every SPTE mapping the GFN range [start, end) in a 58 * preorder traversal. 59 */ 60 #define for_each_tdp_pte_min_level(iter, root, root_level, min_level, start, end) \ 61 for (tdp_iter_start(&iter, root, root_level, min_level, start); \ 62 iter.valid && iter.gfn < end; \ 63 tdp_iter_next(&iter)) 64 65 #define for_each_tdp_pte(iter, root, root_level, start, end) \ 66 for_each_tdp_pte_min_level(iter, root, root_level, PG_LEVEL_4K, start, end) 67 68 tdp_ptep_t spte_to_child_pt(u64 pte, int level); 69 70 void tdp_iter_start(struct tdp_iter *iter, u64 *root_pt, int root_level, 71 int min_level, gfn_t next_last_level_gfn); 72 void tdp_iter_next(struct tdp_iter *iter); 73 void tdp_iter_restart(struct tdp_iter *iter); 74 75 #endif /* __KVM_X86_MMU_TDP_ITER_H */ 76