1 // SPDX-License-Identifier: GPL-2.0
3 #ifndef __KVM_X86_MMU_TDP_ITER_H
4 #define __KVM_X86_MMU_TDP_ITER_H
6 #include <linux/kvm_host.h>
11 * TDP MMU SPTEs are RCU protected to allow paging structures (non-leaf SPTEs)
12 * to be zapped while holding mmu_lock for read, and to allow TLB flushes to be
13 * batched without having to collect the list of zapped SPs. Flows that can
14 * remove SPs must service pending TLB flushes prior to dropping RCU protection.
16 static inline u64 kvm_tdp_mmu_read_spte(tdp_ptep_t sptep)
18 return READ_ONCE(*rcu_dereference(sptep));
20 static inline void kvm_tdp_mmu_write_spte(tdp_ptep_t sptep, u64 val)
22 WRITE_ONCE(*rcu_dereference(sptep), val);
26 * A TDP iterator performs a pre-order walk over a TDP paging structure.
30 * The iterator will traverse the paging structure towards the mapping
33 gfn_t next_last_level_gfn;
35 * The next_last_level_gfn at the time when the thread last
36 * yielded. Only yielding when the next_last_level_gfn !=
37 * yielded_gfn helps ensure forward progress.
40 /* Pointers to the page tables traversed to reach the current SPTE */
41 tdp_ptep_t pt_path[PT64_ROOT_MAX_LEVEL];
42 /* A pointer to the current SPTE */
44 /* The lowest GFN mapped by the current SPTE */
46 /* The level of the root page given to the iterator */
48 /* The lowest level the iterator should traverse to */
50 /* The iterator's current level within the paging structure */
52 /* The address space ID, i.e. SMM vs. regular. */
54 /* A snapshot of the value at sptep */
57 * Whether the iterator has a valid state. This will be false if the
58 * iterator walks off the end of the paging structure.
62 * True if KVM dropped mmu_lock and yielded in the middle of a walk, in
63 * which case tdp_iter_next() needs to restart the walk at the root
64 * level instead of advancing to the next entry.
70 * Iterates over every SPTE mapping the GFN range [start, end) in a
73 #define for_each_tdp_pte_min_level(iter, root, min_level, start, end) \
74 for (tdp_iter_start(&iter, root, min_level, start); \
75 iter.valid && iter.gfn < end; \
78 #define for_each_tdp_pte(iter, root, start, end) \
79 for_each_tdp_pte_min_level(iter, root, PG_LEVEL_4K, start, end)
81 tdp_ptep_t spte_to_child_pt(u64 pte, int level);
83 void tdp_iter_start(struct tdp_iter *iter, struct kvm_mmu_page *root,
84 int min_level, gfn_t next_last_level_gfn);
85 void tdp_iter_next(struct tdp_iter *iter);
86 void tdp_iter_restart(struct tdp_iter *iter);
88 #endif /* __KVM_X86_MMU_TDP_ITER_H */