linux/arch/x86/kvm/mmu/tdp_iter.h
Ben Gardon faaf05b00a kvm: x86/mmu: Support zapping SPTEs in the TDP MMU
Add functions to zap SPTEs to the TDP MMU. These are needed to tear down
TDP MMU roots properly and implement other MMU functions which require
tearing down mappings. Future patches will add functions to populate the
page tables, but as for this patch there will not be any work for these
functions to do.

Tested by running kvm-unit-tests and KVM selftests on an Intel Haswell
machine. This series introduced no new failures.

This series can be viewed in Gerrit at:
	https://linux-review.googlesource.com/c/virt/kvm/kvm/+/2538

Signed-off-by: Ben Gardon <bgardon@google.com>
Message-Id: <20201014182700.2888246-8-bgardon@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-21 18:17:02 -04:00

58 lines
1.6 KiB
C

// SPDX-License-Identifier: GPL-2.0
#ifndef __KVM_X86_MMU_TDP_ITER_H
#define __KVM_X86_MMU_TDP_ITER_H
#include <linux/kvm_host.h>
#include "mmu.h"
/*
* A TDP iterator performs a pre-order walk over a TDP paging structure.
*/
struct tdp_iter {
/*
* The iterator will traverse the paging structure towards the mapping
* for this GFN.
*/
gfn_t goal_gfn;
/* Pointers to the page tables traversed to reach the current SPTE */
u64 *pt_path[PT64_ROOT_MAX_LEVEL];
/* A pointer to the current SPTE */
u64 *sptep;
/* The lowest GFN mapped by the current SPTE */
gfn_t gfn;
/* The level of the root page given to the iterator */
int root_level;
/* The lowest level the iterator should traverse to */
int min_level;
/* The iterator's current level within the paging structure */
int level;
/* A snapshot of the value at sptep */
u64 old_spte;
/*
* Whether the iterator has a valid state. This will be false if the
* iterator walks off the end of the paging structure.
*/
bool valid;
};
/*
* Iterates over every SPTE mapping the GFN range [start, end) in a
* preorder traversal.
*/
#define for_each_tdp_pte(iter, root, root_level, start, end) \
for (tdp_iter_start(&iter, root, root_level, PG_LEVEL_4K, start); \
iter.valid && iter.gfn < end; \
tdp_iter_next(&iter))
u64 *spte_to_child_pt(u64 pte, int level);
void tdp_iter_start(struct tdp_iter *iter, u64 *root_pt, int root_level,
int min_level, gfn_t goal_gfn);
void tdp_iter_next(struct tdp_iter *iter);
void tdp_iter_refresh_walk(struct tdp_iter *iter);
u64 *tdp_iter_root_pt(struct tdp_iter *iter);
#endif /* __KVM_X86_MMU_TDP_ITER_H */